Actron 9580 snapshot scan tool

I get a few questions about using snapshot mode on automotive scanners. It is one of the features I use often when the diagnosis is getting complicated. It’s one of my favorite features of the tool because it can also be useful in pinpointing intermittent car problems that can be difficult to find using other reliable methods.

Let’s say you have an intermittent problem that is caused by a loose or corroded electrical connection to an automotive sensor. The problem turns on the check engine light or causes an issue when the vehicle hits a bump or slams a pothole in the road. The automotive scanner with a snapshot mode can provide data for diagnosis.

Information from the data stream can be reviewed right before and after the vehicle hits the bump or pothole. I have written some reviews of automotive scanners in several price ranges and a few of them are capable of taking these diagnostic snapshots of the data stream. When it comes to Diy auto mechanics it seems that this feature is underutilized.

The automotive computer is your friend

Car Computer

When you get right down to it the primary purpose of OBD II is to make the diagnosis of many automotive problems less complicated. Note that OBD II was deployed on vehicles beginning with the model year 1996 and is still used on present day automobiles. This latest generation of on-board computers also brings a uniform diagnostic platform across all vehicles whether they are foreign or domestic.

One of the things that’s included in this standardized diagnostic protocol is the snapshot feature. Some mechanics call this feature freeze frame mode instead of snapshot but it is basically the same thing. My definition of it is the computer’s ability to record data from all of the sensors and actuators at a time when the system turns on the check engine light or sets a pending fault.

General Motors has taken this one step further and expanded the capability to include failure reports which does the same thing as the snapshot or freeze-frame but also includes any faults stored in the memory. Not just those related to the emission control system. This is helpful because a failure report can include information from the transmission control module responsible for transmission shifting and operation as well as the body computer that is responsible for ABS braking systems, traction control and airbag information on many vehicles.

The basic advantage of using snapshot mode on automotive scanners is the ability to look at the existing conditions when the code was set. This is especially valuable for diagnosing intermittent problems as I mentioned above. Whenever codes are set a record of all related activities is stored in the main computer’s memory. This record allows the mechanic to look at the action of the sensors and the actuators at the time the code was triggered. This can often help identify or pinpoint the cars problem.

I love automotive scanners

Auto Scanner Kit

When I started this article about using snapshot mode on automotive scanners I realized that it sounds more complicated than it actually is. The automobile scanners that are available today provide excellent documentation usually in the form of a CD that ships with the tool. It does a good job of walking you through the different features that the tool is capable of including the freeze-frame or snapshot mode.

A wide variety of car Scan tools are available today. The strength of the included documentation will vary depending on the make and model. I have seen people complain about the directions included with some off brands. When you boil it down the scan tool is a microprocessor designed to communicate with the vehicle’s computer. It is connected to the OBD II diagnostic connector that is usually located just left of the steering column.

The scan tool can access trouble codes, run tests and if it is capable of reading the data stream it can show you the activity of the different sensors in the system. Most people buy these scan tools and just use them for pulling trouble codes and maybe resetting the check engine light. If you spend the money on one these scan tools why not take the time and learn how to get the most out of it! For more recent articles this next link will take you back to the auto repair information blog homepage.

Cadillac SRX Tires

There are lots of places to go to get answers to automobile tire questions. If you have just read that last sentence I’m hoping that I will get a chance to provide some information to you. As a certified master technician I know a lot about the subject. God I love writing about tires. The way the rubber smells when there freshly manufactured, the little nubs on the treads ( Sorry).

I also recently replaced the original equipment tires on my 2009 Cadillac SRX. Not only are the tires expensive but the vehicle only had about 27,000 miles. The whole ordeal was unexpected and expensive. On my vehicle the rear tires are a different size than the front ones. This prevents rotating them on a regular basis (thanks Cadillac). Due to weight distribution and the steering action of the front axle, tire rotation can actually reduce the overall wear therefore extending the life of the tread.

People often ask me including (very cheap) family members when should I replace tires. Usually the question is asked because deep down inside the driver knows that the time is either now or close at hand. For me I lean toward the side of caution and say go ahead and replace them when in doubt. The only contact the vehicle has with the road is through the tires. Add to this the fact that they are made from rubber and even the highest quality tire is going to wear out and need to be replaced at some point.

Checking tires for replacement

When fielding automobile tire questions sometimes I am asked about external damage. To provide a good answer I need to examine it closely. Sidewall damage is common and this could be considered the weakest part. Sidewalls are thinner and are not designed to take the beating that the tread surface does. A deep chunk in the sidewall will usually indicate that replacement is necessary. Especially if the chunk can be peeled back and fiber cords seen.

When I would perform end of car lease inspections the leasing company required that 4/32 of tread be remaining for the tire to be considered good. So for me as a rule of thumb anything less than that would indicate that replacement should be performed. If you are in an area of the country that has a lot of rain, ice or snow then you might want to replace them even earlier.

Tire sidewall

It is the job of the tread to channel away moisture, ice and snow to provide direct contact with the road surface. Tires have tread wear indicators molded into them. These are also called wear bars. When these wear bars show across the width of the tire it is considered worn beyond its limits or ability to do an effective job of channeling away water, ice and snow.

Besides the tread depth you should also check for bulges caused by impact breaks in the reinforcement cords as well as nails that might have been picked up from the road surface without your knowledge. Check them all then roll the car forward a couple of inches and look again.

Things to consider about replacement tires

One of the most important things to consider is your geographic location. This along with the roads that you drive on and their overall condition are sometimes overlooked. Different brands and models will provide different levels of traction, performance and longevity. Speaking with an expert from the tire store is recommended as a starting point. This will often be a person from your area who already knows what conditions you are faced with.

Cadillac tires

With that said you should always do your own research as well just in case the tire store representative is motivated to put you into a certain kind of tire. In my younger days when I worked at one of these specialized locations we were often provided with bonuses for moving a certain brand or model. A good place to go for a second opinion would be the tire rack.

Note that I am motivated to push you in that direction as I am an affiliate of that company. But you can still go there and not buy anything to receive additional assistance. What I like about the website is that it provides a lot of consumer survey results and reviews on different models and brands. I found them to be accurate when looking for replacement tires for my own vehicle.

That is actually why I decided to become an affiliate because of the level of quality of the overall service. To review if you think you need tires you probably do. A good place to go to get your automobile tire questions answered is the Tire Rack. I wrote an article in August that covers a few more options for getting tires. For more information and articles posted to this website this next link will take you to the homepage for the auto repair information blog.

crankshaft position sensor

As an example let’s say the crankshaft position Sensor has failed on your vehicle and it wouldn’t start. Parts and labor including towing would be covered under the base factory warranty. But what if external damage is what caused the problem to the car part.

External damage is considered an accident and not covered under the base warranty. Example: The factory will not be responsible if the automobile fell into a sinkhole and this broke the crank sensor. It would be considered an accident. This means that it is really up to the dealership to determine what has caused the part to fail and whether it will be covered under warranty.

Although many dealerships are honest about this I have worked for a few that were not. I have seen service advisers more interested in how much money that particular customer has spent at the dealership in prior visits and use this to decide what failure code would be entered in the claim.

The vehicle manufacturer has to trust the dealership to some extent because they cannot follow up on every single car problem from each individual customer. This trust does have its limits though. When a warranty problem is submitted to a car maker for reimbursement it contains several codes that help the manufacturer streamline the processing. This is somewhat like what goes on in a medical field.

What is factory warranty coverage

My factory warranty coverage

A warranty is an agreement by the auto manufacturer to have its authorized dealers repair and/or replace certain car parts if they become defective. This agreement normally lasts until the vehicle has been driven a certain number of miles or a certain length of time (whichever comes first).

Just a few years ago the base warranty was most commonly 3 years 36,000 miles. But increased competition and the different car-makers fighting for customers has increased the base warranty time on many models to five years and 50,000 miles or even 10 years and 100,000 miles. As a side effect this has made the extended car warranty harder to sell and cheaper to obtain.

In order for the manufacturer to honor the warranty or to cover the cost of parts and labor the failure must occur within the time and miles of the promised warranty. Often this is not cut and dry because manufacturers provide several levels of warranty coverage. The two most popular at the time of this writing would be the bumper-to-bumper warranty and the power train warranty.

Power train warranties usually last longer but cover less items whereas bumper-to-bumper coverage will last for shorter periods of time but cover many more items. To further complicate matters sometimes on these warranties the owners might be responsible for a partial payment known as a deductible. Then the manufacturer will kick in any money above this agreed-upon deductible this is not publicized on the commercials and ads like the length of coverage.

Things not covered under factory warranty

Cadillac warranty manual

This is where it gets tricky because a standard car warranty provided by the vehicle manufacturer will not cover many malfunctions. Some of the popular ways out would be to say that the failure is caused by an accident, misuse, poor maintenance or abuse or modifications made to the vehicle by the owner that voids the warranty.

What is covered and what is not covered is outlined in your vehicle’s owner manual. You should always read this section of the manual to refresh your memory before you take your vehicle in for what you believe will be a covered warranty service.

Ultimately whether it is covered or not will be up to the dealership that performs the diagnosis and determines not only what the failure is but the cause of that failure. A failed component due to no fault of the driver or owner should be covered under warranty. But the dealer will have to make that decision.

Is your car problem covered under warranty? You can run it by a dealership mechanic at Just Answer below to see what they think. For more of the latest posts this next link takes you back to the auto repair information blog homepage from this article about automotive problems covered under warranty.

New Fuel Tank

Although fuel tank problems are not very common, I have seen issues that needed to be addressed from time to time. Since it’s not a common automotive problem it is also not written about on the Internet very often.

Some of the problems with fuel tanks that we will talk about in this short article have to do with the overall construction of it. These over-sized liquid storage containers are more complicated than most people realize. We will also talk about a vehicle not taking fuel . This is where the fuel tank doesn’t accept the gas fast enough and the pump nozzle turns off while trying to fill it.

Sometimes we think that we will never have to worry about our fuel tanks at all. And in most cases you are correct this is one car part that is engineered well for safety and performance. However as I write this article ford is getting the word out to there customers that it has issued a recall on about a decade’s worth of F150s. Ford is going to replace the fuel tank retaining straps on these trucks because of heavy rusting.

They do not want gas tanks to start hitting the road surface during accidents. Although at this time I have not heard of any incidents of this happening. You can call your local dealer and provide them with your vehicle identification number to see if your truck is included in the gas tank strap recalls.

Sometimes gas tank problems are self-inflicted. As an example when I was a young man, I had a stereo system installed in my 79 Trans Am. the Car audio shop mounted an amplifier in the trunk. After I filled up the fuel tank a couple of times I noticed an overpowering gas smell in the car (not good for smoker). Upon further inspection I found that the stereo shop drilled holes to mount the amplifier right through the fuel tank. This is a good reason to learn how to install car audio and car alarms yourself.

Things to know about fuel tanks

The gas in the tank must survive very cold temperatures and then very hot temperatures as well. To contain vapors and allow for expansion and contraction of the petroleum fluid modern tanks have a separate air chamber that resembles a dome at the top. Also shape and mounting position of the fuel tank only allows for liquid to be installed in 90% of the compartment leaving 10% open for expansion and movement.

Most automotive fuel tanks have slosh baffles or surge plates to prevent gas from splashing around on the inside of the tank they also helps slow down the movement of it. Another advantage of these baffles is they can help funnel fuel to the pump when the tank is low and prevent the fuel pump from sucking dry.

Fuel tank vent

The fuel filler tube looks different depending on the year make and model. All the ones that I have seen have a built-in restriction that prevents the full entry of the larger diesel fuel nozzle. The filler tube itself is mounted well above the gas tank and is usually short in length to prevent kinking. The filler tube is one of the leading causes of a tank to refuse to take gas.

If the tube is damaged or crushed gasoline will not flow quick enough into the tank and the safety on the gas station pumps will kick off. Another reason for a tank not to take fuel would be problems with the venting system. Although car-makers are not allowed to vent fuel vapor into the atmosphere they still vent it to a holding tank. As liquid rushes into the tank pressure can build up during the process. Most modern tanks have a vent system of some kind and when this malfunctions it can make it hard to put gas in the tank.

Check my fuel tank for what

An occasional inspection should be performed and an immediate inspection performed if problems are suspected. They should be inspected for leaks, road damage; metal units should be checked for corrosion and rust, defective or damaged seams. Also the mounting hardware should be checked for tightness and damage.

As I mentioned above on my Trans Am the gas tank was drilled into. Holes in plastic and metal tanks can sometimes be repaired by using special tank repair kits. I do not recommend this personally. When I tried it on my Trans Am it didn’t work. Also you really want to maintain the integrity of the original design.

My last recommendation about gas tanks is if you have to remove one always drain it before you begin removal. It is really harder to pull one that has fuel in it. It can also be dangerous. Give this page a bookmark just in case you run into some problems down the road. Or share this article with a friend that is having fuel tank problems. For more interesting articles this next link will take you back to the home page for the auto repair information blog.

Fuel injection Test kit

I have written about fuel injectors on many occasions and even included instructions on how to do what I consider is one of the best tests. This would be how to perform an injector balance test. Having a fuel pressure gauge mounted up and firing the injector while physically seeing the pressure drop is in my opinion the best way to check a fuel injector.

With that being said not everybody has fuel injection test kit with a pressure gauge and an injector driver. Plus on some vehicles mounting these two testing devices can be difficult. There are several other ways to check fuel injectors.

Remember a fuel injector is nothing more than a solenoid actuated fuel valve. Its operation is quite basic in that as long as it is held open and the fuel pressure remains steady it delivers fuel until the solenoid valve is closed. A fuel injector that is not opening and closing properly can cause hard starting poor fuel economy and other engine problems such as hesitation or rough running.

This boils down to whether the injector is having a hard time opening and flowing the fuel or if the injector is having a hard time closing and shutting off the fuel (dripping).

Another way to check fuel injectors

Believe it or not you can use a mechanics stethoscope to check fuel injectors. This is known as a sound test. This is quite handy if the injectors electrical leads are difficult to access and a power balance test which is also recommended is difficult.

Mechanics Stethoscope

You can start the engine and use the mechanics stethoscope to listen for the correct injector operation. What do I mean by this? A good injector makes a rhythmic clicking sound as the solenoid is energized and de-energized several times a second. If a thud is heard instead of a steady click chances are the problem injector has been found.

On a six-cylinder port fuel injected engine there are six separate injectors. On most models they will be mounted near the intake valve on the cylinder head. You can move your mechanics stethoscope from injector to injector and more importantly then the clicking is that they all sound alike. In fact they should all sound exactly the same.

multi port injector

If a soft click or thud is heard instead of a snap click, cleaning or replacement might be in order. If an injector does not produce any clicking noise the injector connection wires should be checked and a signal from the electronic control module should be tested with a noid light.

If a fuel injector is clicking sometimes and not others the injector plunger may be sticking. This may be a sign of an injector that is beginning to fail. When there is absolutely no clicking from one single injector it is either a malfunction in the control circuit or completely failed part.

You can use an ohm meter to check for the total resistance before spending the money on a replacement part. Each manufacturer has a resistance specification but if the fuel injection windings are open (common on failed parts) the automotive meter will read infinite resistance or out of limits.

Lots of people think that their fuel injection might be the root cause of all of their problems and sometimes it is. But these problems can be verified with some diagnosis. Online auto repair manuals can supply these diagnostic tree charts. If you would like to see more posts to this site this next link brings you back to the auto repair information blog homepage.

Clean throttle body

When I got home I removed the air intake hose and shined a flashlight into the throttle body. It was perfectly clean and almost shiny. It most certainly did not need to be serviced and cleaned. This is not to say that a throttle body service is never needed in fact I do believe they should be done as required.

This would mean a visual inspection to verify it is needed. Therefore if someone recommends this service to you I would ask them why do I need it. If they tell you, because it’s dirty I would then ask them how they know.

The correct answer to this question is they removed the air intake hose and performed a visual inspection. Or they scanned the vehicle and monitored the IAC (Idle air control motor) steps at base idle. If they did not do this I would not purchase the service or at least seek out a second opinion.

What does a throttle body do?

Open throttle plate

The throttle body allows the driver to control the speed of the engine by controlling the amount of air that enters it. The driver pushes on the gas pedal and in the old days the cable would pull on the butterfly inside the throttle body assembly. Nowadays most of these throttle systems are what they call drive by wire.

You can ask Toyota engineers for more details on the system but Basically this means that your gas pedal is now a sensor that sends a signal to the throttle body about how far to open the throttle plate. Each type of throttle body assembly is designed to allow a certain amount of air to pass through it with a particular amount of throttle plate opening.

When the throttle plates are completely closed some air is still needed. This is where the idle air control valve or motor comes into play. The IAC valve meters a small amount of air into the intake manifold. The computer controls the idle air control valve and only allows enough air to keep the engine from stalling. This metering allows the computer to control the idle speed.

The IAC valve can be monitored on an automotive scan tool as mentioned above. How far the valve is opened is counted in steps. The dirtier the throttle body the more steps are required by the IAC valve to maintain engine idle.

Therefore you can actually use the steps to diagnose a gummed up throttle body. As an example if you observe on a scan tool that the IAC steps are around 50 this could be considered a little high. After a throttle body service is performed you would most likely see IAC steps at about half of that or below 25 steps.

How to service the throttle body

new throttle body kit

Modern vehicles are better equipped to compensate for a throttle body that is becoming dirty. So in my opinion the newer your vehicle and the lower your actual mileage, the less likely you need this service. On the flip side of this if you have a 1995 vehicle with 125,000 miles on it and you have never cleaned the throttle body I could just about guarantee that you need a throttle body service.

When carbon and varnish accumulates on the throttle plates or in the throttle bore the amount of air that can pass through into the engine can be reduced. Although this normally causes an idle problem these deposits can be cleaned off of the throttle body assembly and the airflow restored. It is quite possible that you could perform this service on your own in the driveway depending on your skill level.

The carbon deposits can be cleaned with spray type cleaners and wiped off with a cloth. The difficulty of the throttle body service depends on the application. In some cases the throttle body may need to be removed to properly clean the assembly. I use the very complete 3M Diy Fuel System Tune-Up Kit that comes with a DVD on how to perform the service. It is a three-step kit that includes a fuel additive to be installed in the tank.

To review you might need a throttle body service. If you take your vehicle in for regular maintenance or auto repairs chances are your shop will recommend the service to you. Ask them questions to verify that they really checked into it and are not just recommending it by mileage. I posted a video about engine stalling that shows how to do a throttle body service with the parts removed. Or you can use this next link to take you back to the auto repair information blog homepage.

common 4 wire oxygen sensor

Before you replace the oxygen sensor on your vehicle let me make an opening statement. In my own personal opinion this is one of the most often replaced sensors. To make matters worse way too often it doesn’t fix the problem with the car or truck.

In most cases this sensor is not a returnable item at your local parts store because it is considered an electronic component. This is to avoid the try it out before you buy it out driveway warrior. Another problem with replacing the oxygen sensor is deciding which one to replace.

Most vehicles have at least 2 of them installed and four sensor systems are even more common. They are installed in the exhaust stream to sample the exhaust gas.

A check engine light diagnostic trouble code can be set if the part is bad or if the exhaust gas itself is out of balance from a fuel system problem. So how do you determine which oxygen sensor is bad if any. First let’s learn about what an oxygen sensor does and why.

What does an o2 sensor do?

Universal catalytic converter

The signals from the upstream (before the catalytic converter) and the downstream (after the converter) exhaust gas oxygen sensors are used by the electronic control module or the main computer in the vehicle to monitor the current air fuel mixture.

This sensor is a key input signal that will help the vehicle meet or exceed the emissions requirements in the State that it operates in. It will also affect the overall fuel economy of the automobile. This is important to the manufacturers because they are required to meet minimum standards for fuel economy. This is known as c.a.f.e. or corporate average fuel economy. If the car falls below the Government standards it is subject to a gas guzzler tax when purchased new.

The oxygen sensors are threaded into the exhaust pipe near the engine and on some models are threaded into the exhaust manifold. The signal from an oxygen sensor is based on the amount of oxygen contained in the exhaust gases being expelled from the cylinders.

When the sensor signals indicate that this mixture is lean the computer increases the fuel mixture to the engine by increasing the injector on time. When the sensor is reading a rich exhaust mixture the computer would lean the air fuel mixture by reducing the fuel injector on time.

As a rule of thumb if the oxygen level is higher the voltage signal from the oxygen sensor will be low (below 500mv). Likewise if the oxygen level is low the sensors output will be high (above 500mv). This can be important when diagnosing oxygen sensor problems.

Heated o2 sensor

Because the oxygen sensor must operate properly quickly from a cold start most late model engines use a heated oxygen sensor. These sensors have an internal heating element that allows the sensor to reach its optimal operating temperature more quickly and maintain its temperature during periods of engine idling.

Now that the oxygen sensor has become so complicated they are capable of setting many different kinds of trouble codes. There are separate codes for heating system malfunctions as well as the response time of the oxygen sensor, overly lean or rich conditions detected, as well as onboard sensor diagnostics such as resistance determined by a reference signal.

With all the possibilities of things that can go wrong with the oxygen sensor it’s self, there are even more possibilities in the surrounding systems that can set trouble codes. This can make the oxygen sensor appear to be the problem. You can save yourself some time and money by following the individual diagnostic chart for the trouble code that is set in the vehicle’s memory.

These diagnostic tree charts take into account that the oxygen sensor may be indicating a symptom and not actually be the problem with the vehicle. You can visit my other site to learn more about web based versions of the car repair manual. For more articles on this website you can visit the homepage for more auto repair information.

kinds of hose clamps

There are three main things that should be inspected on all cooling system hoses on a regular basis. These would be (in no special order) leaking, chafing or rubbing and swelling. When it comes to checking for leaking hoses most often a problem that is developing will be visible at the hose clamp connection.

There are several different kinds of hose clamps and all of them are capable of having problems. The factory installed spring clamp can lose its spring force over time and develop small cooling leaks or seepage. A telltale sign of this common condition is a crusty or corroded looking area at the connection just in front of the clamp.

This is an invitation to solve the small car problem before it turns into a large one that requires a tow truck and a change of plans. Screw type hose clamps can also loosen up and have reduced clamping force. Back in my dealership days many services included tightening hose clamps during oil change services. You have to be gentle though because Screw clamps can also strip out and lose their ability to be tightened.

Checking cooling hoses video

A visual inspection of all coolant system hoses is a good idea before any road trip. I posted a video on my other website if you would like to take a look. It’s only three minutes and opens in a new window. It is provided by Haynes car care channel and talks about checking cooling hoses. One issue that is not covered real well in the video would be how you should check radiator hoses or rubbing or chafing.

On modern vehicles the engine compartment can be packed together with little room for mistakes or miss routing of coolant hoses. If a hose is out of position it can rub against a metal bracket or even a moving engine belt. This may not cause an instant problem but over time can wear away at the rubber outer wall and cause it to burst when it is under pressure.

Signs of coolant hose problems

new cooling hoses

Sometimes it can be hard to see that a hose is not in good condition because normally cooling system hoses begin to deteriorate from the inside. Any external bulging or cracking of these rubber parts is a definite sign of an imminent failure. You should change any hose that feels mushy or extremely brittle when squeezed firmly.

If a coolant system hose becomes soft it is a sign that it is deteriorating from the inside and it should be replaced before taking that long summer road trip. If the hose is hard or feels like it is crackling as it is squeezed this would be considered a brittle hose and this also should be replaced before hitting the road. Note that if you do not know what it supposed to feel like you can go into a parts store and squeeze a new one.

When it comes to cooling hoses that ruin a summer trip, the upper radiator hose is subject to the roughest service life of any of the rubber parts in the system. It must absorb more engine motion than any of the other hoses. It is exposed to the coolant at its hottest stage and is insulated by the hood which can cause even higher temperatures. This is why an upper radiator hose can be the first one to show signs of problems.

If you find an upper radiator hose that do need to be replaced consider replacing the other hoses and the engine thermostat for good measure. Especially if the vehicle has well over 100,000 miles and these parts are all original. In my opinion another hose that should be carefully inspected would be the bypass hose. This hose is usually small or short in overall length and on many models it is located between the water pump in the engine block.

This puts it in a position where it is also subject to a tremendous amount of heat with very little ventilation or a chance to dissipate the heat that is built up. Although chemical degradation of the rubber from engine coolant is the most common cause of a hose failure heat buildup is probably a close second when it comes to cooling system hoses that ruin a summer trip.

If you would like to see more articles and the most recent posts to this website this next link will take you back to the blog home page from this article about coolant hose problems. It may also be helpful to review the other articles in the auto repair information section before going on that summer road trip.

engine thermostat

When people have an engine overheating condition they often want to head straight for the thermostat. Although this component is a leading cause of overheating it is not the only one. This quick auto repair article is mostly about the other things that can cause high engine operating temperatures.

Often I have been brought a vehicle that was overheating and the customer said go ahead and replace the thermostat. I usually ask them if they would like me to diagnose the overheating or just go ahead and replace the thermostat. The educated consumers usually consent to the diagnosis of the car problem. This also leaves me wide open for the “I told you so”!

In either case if I replace the thermostat I usually go the extra mile and throw the old one into some boiling water and see if it physically opens. Before we move on to other common problems that can cause engine overheating let’s finish up with the thermostat and its technical definition.

The engine thermostat is a temperature responsive water flow control valve. When the engine is cold the thermostat will remain closed allowing coolant to circulate only inside the engine block. This lets the engine warm up fast while remaining at an even temperature. When it reaches the correct operating temperature the thermostat begins to allow some of the heated coolant to flow into the radiator.

Other causes of engine overheating

More than once I have replaced the thermostat, burped or removed the air in the cooling system, taken the vehicle for a ride and found that the temperature gauge still swings up past the normal range. While the car is cooling off the next thing I check for is the available airflow through the radiator and air-conditioning condenser.

engine radiator

On most models the air-conditioning condenser is mounted in front of the radiator. Air needs to flow freely through both of these heat exchanging parts for them to work properly. The operation of the cooling fan pulls air in, but can also pull in dirt, dust, small animals, insects and debris.

I usually take a trouble light and hold it close to the radiator from the inside while I perform my inspection from the outside looking through the grille. On most models this gives a good look at the situation. You should be able to see the light easily through both parts.

I have found some crazy things stuffed between the radiator and the condenser over the years. Some of the bigger offenders such as paper plates and plastic bags can cut off large portions of the radiator and easily cause an engine to overheat. In most cases you can pressure wash these components to get them clean. But in extreme cases sometimes the radiator needs to be removed to be cleaned properly.

Is the radiator clogged

Of course you cannot take off the radiator cap until the engine is cold. In fact when I’m going to inspect the inside of the radiator I prefer that the engine has not been run that day. When you take off the cap, you have to remove some engine coolant to see the condition of the internal passageways.

I have a fluid remover that looks like a turkey baster that works well. You can also put a drain pan under the radiator and squeeze the upper and lower hoses to push out some coolant. Regardless of the mixture of the coolant or the type of antifreeze used some lime, scale and rust will form in the cooling system.

Although some is normal excessive amounts can cause engines to run at higher than normal temperatures. On most radiators with some coolant removed you can see the inlet and outlets of the core passageways with a flashlight. In my opinion anything more than a 25% blockage should be addressed. Chemicals are available to clean rust and scale from the cooling system.

These chemical cleaners are commonly called radiator flushes. Note that when one of these flushing agents is used that they are installed and circulated prior to replacing or actually flushing the engine coolant. After one of these chemical flushes are used, the system should be totally drained, flushed with plain water, and refilled with fresh antifreeze and water mixed to the proper strength. If possible you should use distilled water because it contains fewer minerals than tap water.

Does radiator stop leak work

It is true that chemicals are also available to plug small leaks in an engine’s cooling system. In most cases I do not recommend the use of radiator stop leak. I have seen it because more problems than I have seen solved by using this kind of additive. In isolated cases these chemicals can work to seal leaks in the radiator. But remember they will not seal leaking rubber hoses or connections that flex during vehicle operation.

I have also seen a few cases where people have added multiple cans of radiator stop leak to a vehicle. In one case it ruined the radiator and the engine had to be disassembled to remove the hardened stop leak from the engine block cooling passages. Thinking back on this (Monte Carlo) it was actually the hardest engine overheating I ever diagnosed.

The car was traded in and eventually wound up purchased at auction so the vehicle history was unknown. When I inspected the radiator as explained above I didn’t see the stop leak because it had settled to the bottom of the radiator and sealed the passageways from about halfway down. After figuring that out and replacing the radiator, the vehicle still overheated because the cooling passages in the engine block were plugged with stop leak.

Yes, a thermostat is a common cause of engine overheating. And maybe it should be the first thing you replace, if the part is easy to access. But remember that there are a few other common causes that will make the engine overheat. For more of the most recent articles posted to this website this next link will take you back to the auto repair blog home page.

2002 Toyota Corolla

An ex-girlfriend contacted me on Facebook and was asking me about the recommended motor oil for her 2002 Toyota Corolla. Unfortunately she asked her question after she had her oil changed at a car wash that offered a quick oil change service.

It seems that they had talked her into performing an oil change using the most expensive synthetic oil. They explained to her that this was a much better quality of lubricant and she wouldn’t have to change her oil as much in the future stating it would actually save her money.

The service including a free car wash and was $110 total which is pretty high considering if she chose the conventional motor oil maintenance special it would be around $25 including the car wash. My problem with her going for the synthetic oil change is that I believe firmly in sticking to the vehicle manufacturer’s recommended motor oil.

In the case of a 2002 Toyota Corolla this recommendation is conventional motor oil with a weight of 5W-30. The reason I believe in sticking with the manufacturer’s suggestion is because it is supplied by the engineers and scientists that designed and built the vehicle. I do not believe that I am smarter than the scientists and engineers that studied and tested the engine so it would not require warranty service or in other words blow up. I also do not believe that a service adviser from a quick oil change center is smarter than those same scientists and engineers.

Should I use synthetic motor oil

Cadillac recommended motor oil

Some people ask me if they should use synthetic motor oil. The answer to the question is yes, only if your vehicle manufacturer recommends this type of oil. Again this is just my own personal opinion and many people will disagree including the author of the motor oil Bible. Although I do disagree with him on some areas it still is an interesting read.

Let me give you an example on my own personal vehicle. I own a 2009 Cadillac SRX with a 3.4 L V-6 engine that is also found in the new Camaro. When you look at the oil fill cap, not only does it recommend a synthetic grade oil of 5W 30 but it also recommends the Mobil one brand and includes the trademark symbol for the product.

When you look in the owner’s manual it does not say that you have to use Mobil one but instead gives a long list of API (American Petroleum Institute) standards that must match the engine oil installed in the vehicle if you want to keep the warranty intact. Although it does seem kind of shady that they recommend the Mobil one brand specifically on the oil fill cap, I hold true to what I’ve done for at least the last 25 years or more. I use the recommended motor oil without hesitation even though it is expensive.

Does synthetic motor oil last longer

My 2009 Cadillac SRX

I don’t know, but the recommendations in my owner’s manual states that the 2009 Cadillac SRX provides an oil life monitor and will notify me when oil changes are required. Checking into it a little more by speaking with a Cadillac dealership mechanic he informed me that the oil life monitor uses an advanced algorithm that monitors key cycles and hours of engine operation.

The oil life monitor will recommend an oil change at the 10,000 mile mark or one year since the last reset unless the above algorithm triggers the oil change before these parameters are met. So once again I follow the manufacturer guidelines and change the engine oil when the monitor says it is time to. An interesting development is I was notified of a recall that pertains to this exact subject.

Cadillac has determined that the oil life monitor needs to be reprogrammed so that it will require more frequent motor oil changes. The recall notice stated the reason for this change is they believe that the timing chain might experience excessive wear if you stick to the original guidelines. Therefore they have decided to change the algorithm of the monitor system so that more frequent maintenance will be performed.

It seems that the popularity of performing your own engine oil changes may actually rise and fall with the state of the economy. For those interested or currently performing their own vehicle maintenance I’ve put together a page on my other website that talks about three different recommended motor oil changing tips. If you would like to see the latest posts on this website this next link will take you to the homepage for the auto repair information blog.

2009 Cadillac SRX

This next article about automotive air filter maintenance is just an opinion from a mechanic. Sometimes since mechanics are educated in the ways of the automobile they may find themselves becoming more vigilant when it comes to their own maintenance of their beloved personal automobile or cars that belong to family members.

My latest vehicle a 2009 Cadillac SRX recommends in the service manual that the air filter be replaced every 25,000 miles. In my opinion this would just be a guideline because the operating conditions may require that the air filter be replaced more or less. When I bought the vehicle used it had 22,000 miles on it. I pulled the air filter for inspection and it was 90% blocked.

So before we get into the article about automotive air filter maintenance keep in mind that your results may vary depending on your operating conditions and what kind of air filter your vehicle is equipped with in addition to its physical size. Smaller air filters will become blocked easier than large surface area air cleaners.

What is an automotive air filter

checking automotive air filter

The primary function of the automotive air filter is to prevent airborne contaminants from entering the engine. If these contaminants are not filtered out they can cause serious damage and even shorten engine life.

Let me give you an example that I recently dealt with of a worst-case scenario. The county I work for has three trolleys that operate up-and-down the beach. Although they have bus bodies they have diesel pusher engines.

The air filter assembly that came from the factory had an air pickup that was mounted low to the ground on the right side of the engine compartment. This was a very bad position for these vehicles as the air filter would pick up sand and dust from the beach.

The air filters would become plugged quickly and some developed holes that aloud raw sand to be sucked into the combustion chamber of the engine. It wasn’t until the first engine failed within 15,000 miles that we notice what was going on. We changed the air filter design and relocated the air intake and the problem was solved.

How an automotive air filter works

Air filters are basically assemblies of pleated paper supported by a layer of fine mesh which can sometimes be made out of nylon or wire that resembles a screen. The screen provides the paper with some strength and also helps to filter out the extremely large particles such as leaves and big chunks of dirt.

Again your air filter may vary but it will have some kind of thick plastic or rubber like gasket material on the ends of the filter. This thick silicone or plastic like gasket also add strength to the automotive air filter and assures a good seal so that all air is filtered through the paper before it enters the intake manifold.

If the filter does not seal well in the housing dirt and dust can be pulled into the air stream and into the combustion chamber as I described in the problem with our trolleys above. The shape and size of the air filter element depends on the housing itself the two most common designs in modern vehicles would be a flat paper type like in my 2009 Cadillac SRX or a round or cone type automotive air filter that is popular with pickup truck manufacturers.

On some vehicles checking air filters is an easy operation. On the other hand some vehicles make it very difficult to remove the air filter for inspection. Check your auto repair manual for the procedure as well as the recommended guidelines for inspection and replacement. For more of the latest articles to this website you can visit this next link that takes you back to the auto repair information blog home page.

Floating disc brake caliper

I wanted to provide some standard brake job tips that can apply to both do it yourself driveway mechanics and auto repair consumers that plan on dropping their vehicle off for brake service. Learning a little about the process can help you get the most out of your brake jobs.

In some auto repair publications they have done tests that show that when only the pads are replaced without reconditioning or replacing the caliper hardware that the new pads can wear out faster than original equipment brake pads installed from the factory.

It is often rusting and corrosion that causes this premature wear. When the calipers do not float as per design intent then the brakes can drag slightly causing this increased wear. I have more details about the different kinds of disc brakes and how they work plus an auto repair video at the very end of this article.

This is my primary brake job tips recommendation! When you are performing your own brake service or you’re having a shop do it for you, replace or fully recondition the hardware that allows for the free movement of the calipers. Think about where this hardware is located. Down by the tire and close to the road where it is exposed to water, salt, potholes and road debris.

In fact most manufacturers recommend that these pins and bushings be replaced each time the caliper is removed. This is a good idea because the pins and bushings are usually inexpensive and will assure not only longer pad life but also more efficient even braking.

Getting a good brake job tips

As a mechanic when it comes to performing a brake job whether it’s on my own vehicle or a customer’s car I always insist on taking a road test before work begins. This way I know what the brakes feel like before I take them apart.

This can also greatly reduce poor communication between the mechanic and the driver. Sometimes people will take their vehicle in for a brake job, drop the vehicle off and say replace my front brakes. The driver of the vehicle may feel that a specific problem will be solved by that operation without notifying the shop of the problem.

Another major brake job tips is I will not release the vehicle after a brake service has been performed without driving the vehicle myself. Often mechanics and shops can be so pressed for time that they will install the pads and park the vehicle in the lot to be picked up by the customer.

First of all new brake pads may need some brake in time before they will feel like the old brake pads did. I road test the vehicle and perform both panic stops and regular braking to make sure everything went as planned. It is very important for the vehicle to stop the same way or better as when the driver dropped off the automobile for service.

Types of disk brakes

Single piston brake caliper

The disc brakes in use today are typically of two basic designs. I believe the most common would be the floating caliper design. But you can also find the fixed caliper design as well. There is also a sliding caliper but this is very similar to a floating caliper type disc brake system.

The difference between a sliding caliper and a floating one would be that the sliding type has a smooth machined surface that it moves up and back in. The floating calipers will slide on special pins, bolts and bushings. On this type there is a space called an air gap between the mounting bracket and the caliper. On full floating type brakes you will usually have pistons on only one side of the caliper.

Fixed caliper disc brakes have an assembly that is bolted in a fixed position and does not move when the brakes are applied. In this type of situation the caliper will have pistons on both sides that use hydraulic force multiplied from the driver’s foot to force the brake pads against the rotor. This friction is what stops the vehicle with authority.

Learning about what type of braking system is on your specific automobile and being able to discuss this from an educated position can increase the chances of getting a quality brake job. I have built a repair module on the you fix cars website that walks you through other important brake job tips. If you are interested in seeing the latest post on this site this next link takes you back to the auto repair information blog.

ABS warning light

Some drivers are known for putting off car repairs like regular maintenance. Things like oil changes, coolant flushes and tune-ups can seem unimportant when the car is running good.

Often drivers even put off diagnosing warning light problems such as abs lights, airbag light and check engine lights but few will ignore car brake problems.  Let me use my sister as an example (sorry Sis).

I got into her car the other day and the check engine light was on. I asked her how long the light had been shinning in her face. She told me that it’s been about 10 days and she was meaning to talk to me about it. When this same young lady had a brake system problem she called me immediately so that I could diagnose it.

Some common car brake problems

Disc brake rotor

A lot of times drivers will complain about the way the brake pedal feels when they apply the brakes. A sinking brake pedal can give you the feeling that the vehicle may not stop. A common cause of brake pedal fade (but not the only cause) is a braking system that is overheating.

Any braking system must be able to effectively handle the heat created by friction within the system. This tremendous amount of heat created by the rubbing brake surfaces must be conducted away from the pad and rotor and be absorbed by the out side air.

Automotive brakes that do not effectively dissipate heat can experience brake pedal fade during hard or continuous breaking. The linings of the pad can become glazed as well from this heat buildup. The rotor can also become glazed. When you have a glazed rotor and pads the friction action is greatly reduced. To the driver this will feel like the vehicle does not want to stop.

The way I prefer to correct this condition is to disassemble the front brakes and physically sand the glaze off of the friction material. For auto repair safety reasons you always want to wear a dust mask when doing this. On the rotor side either they will need to be resurfaced on a brake lathe or if they are composite rotors they may need to be replaced.

Getting to the bottom of car braking issues

The root cause of the overheated brakes and glazing issue will still need to be addressed after the repairs mentioned above are completed. The cause of overheated brakes can be traced back to a few different things. For one thing it could be the habits of the driver.

A 2 foot driver that constantly hovers their foot on the brake pedal can actually be applying the brakes slightly while driving. This can cause overheating problems because the brakes are continuously applied and they are not allowed to dissipate their heat as they would during normal operation.

Another possible cause of overheated brakes could also be traced back to problems with the braking system. If a caliper is binding and not fully releasing when the brake pedal is released the same results could happen as in the 2 foot driver scenario. When people have a binding brake caliper it also in most cases will cause other problems such as a pulling condition.

When inspecting brake pads and binding calipers are suspected you can often find glazed pads and rotors on only one side of the automobile. Also common with this car brake problem would be uneven wear comparing the inboard pad to the outboard one. If this subject interests you I have built a repair module on the you fix cars website that talks about car brake problems in-depth. Or you can head back to the homepage for this blog for more auto repair information articles.

Car Battery

I have written a lot of articles about car batteries and charging systems. One question has come up frequently that seems to have fallen through the cracks of the articles that I have already written about the battery and charging system on modern-day cars.

This frequently asked question about the vehicle’s car battery is after the engine is running is the battery doing anything besides charging back up. The short answer to this question is no. The battery is used primarily for starting the engine.

In fact during cranking it is the battery that supplies all of the vehicles electrical power. However once the engine is running it is the alternator that is responsible for producing enough electrical energy to meet the demands of all of the vehicles loads. This would include things like operating the wipers illuminating the headlights and even charging your cell phone.

After all of the current demands have been met any excessive electrical power available is used to recharge the vehicle’s battery. This is one of the more important details about car batteries. With the increase demand of vehicles optional accessories for some motorists the excessive electrical current used for charging the battery may be in short supply.

This is also why that the vehicle run time between engine starts is also so important. If only a small amount of excess electrical current is being funneled to the battery then a longer run-time might be required to fully charge the battery for the next starting cycle. I have written a complete article on this subject that discusses how long a car battery will last.

Monitoring the car battery

Car Altenator

Another question I get about car batteries is what to do when a warning light comes on in the dash panel. Most often these warning lights illuminate in red because they are important to the overall vehicle operation.

It is very important to monitor these warning indicators because they directly relate to charging system performance. On some vehicles as a bonus they provide an ammeter or volt meter gauge in addition to a warning indicator light.

This will allow the driver to monitor the charging system performance more accurately. A positive charge indication on the gauge allows the driver to know that the alternator is doing its job and charging the battery.

Alternator warning light

The warning indicator light is the simplest and most common method of monitoring the alternators output. When the alternator warning light is turned on it’s an indication that the charging system is failing to supply sufficient current to the battery.

Inside a car battery

Also remember when the ignition switch is first turned on this light will also come on because the engine is not running and the alternator is not providing current or voltage. This is known as the bulb check function. The alternator warning lights should go out after the engine is started.

If the light does not go out it could indicate a problem with the alternator itself. Although this would be the most common reason for the light to come on and stay on other problems in the system may cause a false indication of a problem. Depending on the vehicle, a faulty relay or wiring connection can also turn on the alternator warning lights.

This is why it is recommended to perform some diagnosis before jumping in and replacing an alternator. Most automotive repair centers offer an inexpensive charging system analysis. The test in most cases is a quick one with a simple connection to the battery. Also many chain stores will perform the test for free if repairs are done at their shop.

The testing equipment is also not very expensive, for example the Clore Solar BA7 battery and alternator tester above. It can be very handy to have in your garage so that you can diagnose the problem yourself. If you need more information about this subject I have built a page about what to look out for when replacing a car battery. For more of the latest posts to this blog this next link takes you to the homepage for the auto repair information blog.

Torque Converter Clutch

I have written about torque converter clutch problems in other posts but this one will be a little different. Most often when I have a problem with the converter clutch lock up causing an engine stalling condition I find a problem with the tcc solenoid.

But this is not always the cause of the problem. In fact the last time I faced a converter clutch lock up problem I went for the solenoid right away and it did not fix the issue which was an engine stall only when put into reverse gear. On this particular repair I ran into a clogged transmission cooler.

Although this was the first time I have ever seen this component cause a stalling condition, after checking into the situation it made a lot of sense. The drivers complaint was different this time around then the usual complaint associated with torque converter clutch problems.

The driver stated that the stalling condition was most often when he put the vehicle into reverse. Especially when the engine was cold, like in the morning while backing out of his driveway. In most cases when you have a torque converter solenoid issue the engine will stall as you slow down for a stoplight in a forward gear.

Transmission cooler problems

TCC Solenoid

Some vehicles equipped with a converter lockup clutch might stall when the transmission is shifted into reverse gear. The cause of this problem might just be a plugged transmission cooler or clogged cooler lines and not the tcc solenoid.

The reason for this type of torque converter clutch problems is that the transmission fluid normally flows from the converter and directly through the transmission cooler. If the cooler passages are blocked fluid is unable to exhaust from the torque converter and the converter clutch piston can be forced to engage when reverse is selected.

Although as I mentioned this condition is not a common one, the test procedure is not that difficult to perform. And could save you from replacing a good TCC solenoid which on some models is not an easy task. If you want to verify that the transmission cooler is plugged you have to disconnect the cooler return line from the radiator or the external cooler if your vehicle is equipped with one.

Transmission Cooler

Next you connect a short piece of rubber hose and to prevent it from slipping off the line you can use a couple of hose clamps. Put the end of the rubber hose into an empty bucket or large container. Next you start the engine and with the vehicle in park and the wheels blocked and you measure the amount of fluid that flows into the container after 20 seconds.

A good rule of thumb is that normally 1 quart of fluid should flow into the container in about 20 seconds of run time at engine idle. If less than that has filled the container it may be an indication of a plugged transmission cooler.

Some people prefer to try to clear a blocked cooler by using compressed air. I recommend replacing the cooler whenever possible. But if you do decide to use compressed air make sure you limit the air pressure to below 50 psi or you can cause internal damage to the cooler.

The reason I prefer to replace the part is because the little pieces that are left behind can work their way into the transmission or even clogged the filter. This can cause expensive internal damage to the transmission. A replacement external cooler is around a $100 and can save you a lot of aggravation.

If you are interested in learning more about transmission operation and seeing some common problems with specific models I have a section dedicated to the subject on my you fix cars website. You can learn more about the theory and operation of the torque converter and review some more automatic transmission problems. If you are interested in seeing more recent posts here visit the auto repair information blog homepage.