1988 300ZX ( Christine )

The mighty 300ZX failed the emission test the last year I owned it. I was getting ready to sell her and decided to run it through the state inspection early so that prospective buyers could see that she just passed the state inspection. I thought this would be a good selling point.

At the time I was living in the state of New Jersey which has very strict testing that causes vehicle owners to suffer great anxiety when their automobile is due for inspection. The state workers always seem to find something to fail you on, and therefore proving that their job is a necessary evil.

But when it came to my 1988 300ZX (Christine we called her) it always sailed through the yearly inspection. For one thing, the emissions standards that the vehicle had to live up to where the older 1988 specifications. In 1988 some vehicle manufacturers were actually still installing carburetors on new vehicles. This prevented the federal government from stiffening the standards until all vehicles went with fuel injection the next year.

The 3.0 L V-6 Nissan engine not only had fuel injection but it had a computerized system that was ahead of its time or at least on the cutting edge back in 1988. If the 300ZX fails an emissions test it means that something is wrong. But “Christine” ran beautifully with no signs of smoke and absolutely no roughness at idle. To be honest I thought maybe the states equipment needed a calibration. I took the vehicle into a friends shop and sure enough the vehicle did have high HC (hydrocarbons).

Why did the 300ZX fail emissions

This is just my opinion but when a car does fail inspection for HC the most common cause for high output of hydrocarbons is an engine misfire. This did not apply to the Z. Hydrocarbons or high HC is usually caused by unburnt fuel or raw gas making its way into the exhaust system.

300zx computer

High HC can also be caused from a rich mixture but this would usually apply to a carburetor vehicle where you can make adjustments to the air fuel mixture. On a fuel injected vehicle this is calculated by the computer which controls how long the fuel injector stays open.

My 1988 300ZX was running rich but there was no screw that I could turn in to lean out the mixture. This actually did take me a while to figure out and I’ll have to spare you all of the little details and all of the different things that I checked and skip right to the meat and potatoes of what the problem was.

How did I solve the 300ZX problems

300zx fuel vapor canister

What really led me to solving the problem was grabbing the 300ZX repair manual and completely reading through the fuel management section. I got to the section that described the vapor canister and purge valve system. I thought this was an emission related system that was worth checking into.

The canister is quite different than the one that is deployed on modern-day vehicles. And when you get down to it, a two position control valve controls the burning of the fuel vapor at the proper time. The valve was stuck in the open position and venting fuel vapors to the intake at engine idle.

The computer can usually compensate for this condition but in this case the canister had raw gas in it. This was due to a stuck fuel check valve. I never heard of anyone else with a 300zx have this problem. The solution was replacing the canister and control valve assembly that I bought new through the Nissan dealer.

300ZX crankcase emission control system

In case you’re wondering how fuel vapor is handled on the 300ZX models I will provide a short description to follow. The fuel vapor from the sealed fuel tank is led into the canister which contains activated carbon. The vapors are stored there when the engine is not running. There should be no raw fuel present, it is a vapor canister. There is a liquid check mounted near the tank to prevent this.

The canister retains the fuel vapor until it is purged by the air drawn through the purge line to the intake manifold when the engine is running. When the engine is at idle the purge control valve is in the closed position. As the engine speed increases and the throttle vacuum rises higher, then the purge control valve opens and the vapor is drawn into the intake manifold through the purge orifice.

I did love my 300ZX and it eventually did sell for the full asking price. The brand-new state inspection sticker did seem to help the buyer feel better about paying top dollar for the car. If you are interested in seeing the other work my 300ZX required this next link takes you back to the 300ZX auto repairs section. If you’re interested in seeing the latest articles posted to this blog this next link will take you to the auto repair information blog homepage.

Nissan Starter Motor

Replacing a Nissan starter motor on the 3 L V-6 is a fairly common repair on this engine. Shortly after I purchased my 1988 Nissan 300ZX one of the first repairs that was needed was replacement of the starter motor.

The first thing I noticed was that it was not the original starter. When I started to look through the paperwork that came with the vehicle I noticed that this was actually the third time that it was replaced on this car in 100,000 miles. This seemed to be excessive in my opinion.

My goal was to find out why this vehicle needed another one. It did not take long to find the answer. And the reason I tell the story is because I believe this may be a common problem associated with a Nissan 3 L V-6 engine whether it is in a Nissan Maxima sedan or a 300ZX.

The starter motor in my 300zx was covered in a thick layer of dirt and slime. The reason for this is the oil filter is located directly above the starter and solenoid assembly. When you go to perform an engine oil change and you start to unscrew the filter about 6 ounces of oil will run all over the starter motor.

If you do not take the time to clean up the oil then when you begin to drive the vehicle dirt will stick to that thin layer of oil. If you change your engine oil every 3000 miles as was recommended by the manufacturer for this engine you can see how much oil and dirt could build up over a short period of time. On a side note if you go to a quick lube center the word quick stands for fast and do not usually include cleaning any residual oil.

Starter motor failure Nissan 3 L V-6

Nissan auto repair manual

With multiple layers of oil and dirt covering the motor and solenoid heat buildup and retention of that heat is increased greatly. When I removed the assembly I decided to take it apart and see what went wrong inside. Some oil made it inside the motor assembly and was covering the windings and brushes. I have a page on my other site about starter motors if your interested.

The armature assembly, field coil and brush holder was a purple and blue-ish color. So the starter literally burned up from the inside out. Although this assembly can be rebuilt I decided to go ahead and replace it because I could not locate an overhaul kit for it. And I did decide to spend a few extra bucks on a factory original Nissan replacement part.

88 300zx

This was the last time I had to replace the Nissan starter motor on my 300ZX. The reason this was the last time is because during every oil change I would take a few rags and cover the starter before I began to loosen the engine oil filter. The rags would soak up the oil and when the maintenance operation was completed I cleaned the area with electrical cleaner so it looked like brand-new again.

Without the oil and dirt buildup on the starter motor itself I never had another problem. As far as all the cars I owned over the last 30 years my Nissan 300 Z was the most troublesome. In all due fairness to Nissan this was also the only car I bought that already had 100,000 miles on it. If you’re interested in some of the other repairs that were required visit my Nissan 300ZX repairs section. For more general automotive repair articles visit this blog’s home page and get some auto repair information.

300ZX AC Problems

I had a few 300ZX air-conditioning problems with my 1988 Z. in case these are problems that are inherent in these vehicles I will describe them below. When I got this car it had r12 Freon in the system as you would expect from an older vehicle such as this.

Me being an automotive mechanic that has converted many systems, I was prepared to do the same to this vehicle. I did have a 1 pound can of r-12 Freon that I used to bring the system up to its proper level when I first got the car. I was expecting that someday I would have to convert the system to the new R-134a. To my surprise I did have problems with the air-conditioning system but never had a refrigerant problem so I never converted the system.

I have put a page together on my you fix cars website that has more tips and directions for people that want to convert from r12 to 134a. There is more to the procedure then just dumping one and installing the other. In fact if you do not follow the recommended procedure your air-conditioning system will probably not blow cold for long.

Nissan blower motor problems

My 300ZX was equipped with Nissan’s continuously variable airflow control. This means that there were more settings than just medium-low and high. And the system was actually quite complicated. There was a fan control amplifier which utilized a series of transistor-based circuits that continuously controlled the airflow blown out by the blower.

Blower motor pushing air through evaporator

This allowed for a selection of infinitely variable airflow rates. The fan control amplifier is housed in the blower motor case itself. There is a heat sink radiating plate mounted on the amplifier assembly and it is placed in the airflow of the blower motor to provide cooling to the transistors to prevent electrical heat failure.

When my 300ZX reached about 12 years old I started experiencing intermittent airflow operation and I could hear the blower motor kicking on and off. When I pulled out the fan control amplifier I didn’t see any melting or actually any problems but it was the culprit and needed to be replaced. I got the replacement part from the junkyard and never had any other blower motor problems with the car.

Nissan AC problems

I did have 300ZX air-conditioning problems that were not a Freon related issues. At first I thought it was, because the problem was the air would start off cold and then get warmer the longer you used the AC system. This is a typical symptom of an evaporator freezing up. One day I ran the air-conditioner until it started to warm up and I pulled the evaporator cover off to find a solid block of ice.

It’s funny that when the evaporator is frozen solid into a block of ice that the air actually gets warmer. But it is true because the airflow through the cooling fins is reduced and diverted around the evaporator assembly instead of flowing through it.

Nissan AC expansion valve

On a 300ZX air-conditioning system the compressor cycles on and off to maintain the proper evaporator temperature. When the evaporator temperature falls below a specific point the Thermo control amplifier interrupts the compressor operation by disconnecting power. When the evaporator temperature rises above the specification power is restored to the compressor.

The late 80′s Nissan 3 L V-6 air-conditioning system uses an expansion valve with a capillary tube that provides the temperature input from the evaporator. On my 300ZX the capillary tube leads to a bulb on the end that attaches via a clip to the evaporator fins. I’m not sure how it happened but it became detached and was just laying in the evaporator case and was not providing the proper input temperature. I cleaned the temperature bulb and reattached it to the evaporator fins and the problem was solved.

On this auto repair information blog I have written a lot about my 300ZX and the repairs that were needed. This was one of my favorite cars but also required the most work out of any automobile I had ever owned. It was also my first Nissan so it taught me a few lessons about Japanese cars. I have also written many air-conditioning articles and you can head back to the main page and see the latest auto repair blog posts.

Clutch Kit Parts

My 300ZX clutch problems began with a rear main seal leak. It wasn’t long after the clutch started slipping that the Z wouldn’t move at all. When I put the vehicle up in the air to check it out I saw what was going on.

The rear main seal wasn’t leaking very much but it was enough to cause the clutch to fail. Oil and friction material such as the type that is contained on the clutch disc don’t go well together.

The clutch disc friction material actually begins to soak up the engine oil like a sponge. A slippery spongy clutch is the opposite of what you need to move the vehicle properly.

This type of clutch problem is actually quite common and happens to many manual transmission vehicles from manufacturers both foreign and domestic.

300ZX flywheel problems

I pulled the transmission and remove the clutch and pressure plate. I could see that there was some heat scoring and a bluish color to the flywheel surface. I decided to send the flywheel out to be resurfaced at a local machine shop.

OEM Clutch Kit

Since I wasn’t into racing at the time I just decided to go with a standard clutch kit that included a new pressure plate and throw out bearing. I got the flywheel back and it looked very nice. I put it all back together with the new rear main seal and although the clutch moved the vehicle it would slip under heavy loads.

I suspected that the pressure plate from the cheap clutch kit was the problem. It appeared to me that there was not enough clamping force. When I pulled the transmission back out and once again removed the clutch and pressure plate the flywheel surface was again a bluish color.

I called the supplier of the clutch kit and told them what was going on. The first question they asked was, did I have the flywheel resurfaced. They suggested I check the thickness of the flywheel to make sure it was not over machined.

I never thought to check the work of the machine shop. But that was exactly the case. They took too much off the flywheel surface and it was now undersized. After purchasing a new flywheel and talking the clutch kit supplier into sending me a new friction disc I put it back together. Problem solved the clutch had full grabbing power and no slippage.

More 300ZX clutch problems

After about two weeks of happy driving I was at a stoplight and had the clutch pedal depressed to the floor and the gear selector in first waiting for the light to turn green. I felt the clutch pedal starting to fade and the car started to move forward.

Clutch master cylinder

I popped it in neutral and pumped the clutch pedal and it returned to normal. This began to happen more often. The clutch was fading just like a brake pedal does when a brake master cylinder is failing. The clutch master cylinder is very similar to a brake system one.

Long story short after my clutch job as described above it was necessary for me to bleed the hydraulic clutch system. I got distracted and I left the master cylinder cover off for several hours. The clutch hydraulic system uses brake fluid that is considered to be hydroscopic. It absorbs moisture quickly.

With the clutch hydraulic fluid contaminated it destroyed the seals in both the slave cylinder and the clutch master cylinder. Since the hydraulic hose that connected the two cylinders was also made of rubber I decided to replace that as well. This turned out to be the most expensive clutch job I have ever seen in my 25 years in the auto repair business.

The 300ZX can be a very unforgiving automobile. I never owned a car that I loved so much and yet had so many problems with. In the defense of Nissan products, I did buy the vehicle 10 years old and with 100,000 miles on it. I expected it to be a hobby car. It actually turned out to be a vehicle that taught me a lot of lessons.

If you’re interested in what other lessons this vehicle taught me you can visit my 300ZX repairs page to see the ever growing list of what went wrong and how I fixed it. If you’re interested in seeing the latest posts this next link will take you back to the auto repair information blog.

When I purchased it and left it outside, the rainwater quickly found its way inside the rear hatch compartment. It turned out that this water leak is quite common on both the 280Z and 300ZX.

Unfortunately I wasted some money on trying to get this leak fixed before I looked into technical service bulletins. I figured since the hatch compartment was wet that the aging hatch seal must be the cause of the hatch water leak.

I purchased a new hatch gasket from the dealership and this cost me around $150. After replacing the hatch seal I anxiously waited for the next rainfall to come and go. To my disappointment after a hard rain the rear hatch compartment was again like a miniature swimming pool.

How to repair the 300ZX water leak

After my first attempt failed at repairing the hatch water leak I looked into technical service bulletins as well as performing an Internet search. Many Z owners had reported the same type of rain water leak. Find out more about Car Repair Bulletins here.

The technical service bulletin stated that the water was entering from the tail light assembly’s. The taillights on the 300ZX attach through the rear compartment wall. Water was dripping onto the threaded screws and traveling into the rear hatch compartment.

The fix was to completely seal the taillights assemblies and stop the water from reaching the threaded screws that entered the rear hatch compartment. The silicone sealing job did not look very neat but was very effective at stopping the water.

The good news was that when the hatch lid was closed there were no signs of silicone. So the messy silicone seal job was my dirty little secret and could not be seen by others checking out the overall beauty of my 300ZX.

Why you have to fix water leaks

Water collecting in the rear hatch compartment can be very destructive to the health of the overall automobile. Yes the main problem will be rust developing in the bottom of the hatch compartment. And trust me replacing the bottom of the hatch compartment is a lot more difficult than repairing a water leak.

Another destructive part about having water lying inside of the car is the increased humidity level inside the vehicle. This can greatly accelerate corrosion throughout the interior spaces of the automobile. Things like connectors and wiring harnesses will start to turn green and provide intermittent connections quickly. Also components such as control modules and relays can be negatively affected by a hatch full of water.

But one of the most destructive properties of an interior compartment full of water is the effect on the grounding locations. Vehicle system grounds can quickly become corroded in a humid environment.

Poor ground connections are often the first problem that develops from an interior water lake. Many weird electrical problems can start to develop from poor or intermittent ground connections. If you’re interested in what other repairs this car needed you can visit the Z section of this blog. This next link takes you there from this page about 300zx water leaks.

Odometer 3.0L v6

How many miles can you put on a Nissan 3.0 Liter V-6. The answer to this question is similar to the answer of how many licks does it take to get to the center of a Tootsie roll Tootsie Pop.

When I purchased my Nissan 300ZX it was from the original owner and the odometer was showing almost exactly 100,000 miles. My parents thought I was insane for buying a vehicle with such high mileage.

Back in my parent’s days when a vehicle reached the 100,000 mile mark it was time to throw it away and get another vehicle. But as we know today, we can get many more miles than we use to just 10 years ago.

The 150k mile mark is common place now. If the engine is well built and cared for 200,000 miles is well within reach for many drivers.

300ZX V-6 engine

I plan on dedicating a few posts to the 300zx repairs that were necessary while I owned this car. This car required more work than any other vehicle that I have owned before or since. But this post will be dedicated to the engine itself the mighty 3.0 L Nissan V6.

3L V6 300ZX

When I got this car with 100,000 miles on it I wasn’t sure how far the engine would go. Being a mechanic I figured that I would have to either overhaul or replace it at some point. The first thing I had to do after purchasing the Z. was to get it through state inspection.

The vehicle did fail for loose ball joints and alignment issues but it passed the emissions test with flying colors. Also notable was at 100,000 miles the 3 Liter V-6 had fantastic oil pressure at about 30 psi at 800 RPMs.

The engine had zero smoke emissions and purred like a kitten. I owned this car for about four years and put an additional hundred thousand miles on the Nissan v6 motor.

At that point the engine still had 25 psi of oil pressure at 800 RPMs. With the odometer showing 210,000 miles the day I sold the vehicle there was still no sign of smoke or any other signs of worn internal engine parts.

Now keep in mind that I am a mechanic and I loved this car with all my heart. It received oil changes every three months or 3000 miles religiously. So it was well cared for but still it exceeded all of my expectations about how many miles I could put on a Nissan 3.o Liter V-6.

Oil change tip for the v6 Nissan engines

As a side note every time you do an oil change on this engine the oil filter is located above the starter motor. When you remove the oil filter oil will run over the top of the starter motor. If you do not clean the oil off the starter it will eventually overheat and need to be replaced.

If you go to a quick lube, chances are they will not take the time to clean the area around the oil filter. You may want to double check this unless you do not mind replacing the starter every 5 years or so.

So I really can’t answer the question of how many miles you can put on your Nissan 3 Liter V-6 but as far as the engine in my 300ZX the last I heard it had over 240,000 miles on it and continued to pass state inspection and have good oil pressure. In my opinion Nissan makes a very stout V-6. If you take good care of it the skies are the limit for the longevity of this motor.

For more details about this car related blog the homepage is available from the next link. Go from the Nissan 3.0 Liter V-6 to auto repair information blog.

My 1988 300ZX

This story is about my 300ZX manual transmission. Specifically about how my ignorance completely destroyed it to the point that it could not be repaired. First some background information about the car and where it came from so the rest of the story makes some sense.

I was always attracted to the 300ZX sports car. When these vehicles first came out, I could not afford to get one. But in 1998 I decided that I could afford a 10-year-old one as a hobby car or investment. I found a 1988 300ZX 2+2 in pristine condition that was garage kept by the original owner.

I was living in New Jersey at the time and the Z was located in South Carolina. After talking with the owner and seeing pictures online I decided to take a road trip with a friend and go see the vehicle. It was everything that I hoped for and I negotiated a cash sale with the owner. I then had the vehicle shipped back to New Jersey.

I drove the vehicle for several months with absolutely no problems. This car was going to be a hobby car but wound up being my everyday transportation due to circumstances beyond my control. In Jersey We had a brutally cold winter in 1998. And as we got into late December my manual transmission on the Z began to make some noise while driving in any forward gear.

I checked the fluid level in the manual transmission and it was filled properly. But what I didn’t realize was that it was filled with 75W90 gear Oil. I continued to drive the vehicle out of necessity and the noise quickly got worse. The 300ZX came with the original owners manual from 1988. I checked the manual transmission fluid recommendations in the owners manual.

300ZX manual transmission facts

Manual for 300Z

To my surprise the 75W90 gear oil is recommended only for conditions above 40° the manual stated in colder conditions below 40° that automatic transmission fluid should be used. The gear oil worked fine while the vehicle was living in South Carolina. But the extreme cold of New Jersey thickened the lubricant to the point where it was not flowing properly through the transmission.

This lack of internal lubrication did an extreme amount of damage inside the transmission. I disassembled the unit and was extremely disappointed to find a lot of metal inside. But the problem was most of the metal was aluminum.

The case of a 300ZX manual transmission is all aluminum. The lack of lubrication caused case damage that made the five-speed FS5W71C unit unrepairable. Most of the steel gears, shafts, bearings and even the brass synchronizers were in good condition.

Used 300ZX five speed transmission

300Z manual transmission

When I started looking around for a replacement transmission there was not too many options. I had to get one from the junkyard and fix it up. When I replaced the transmission I also installed a new clutch kit and had the flywheel resurfaced.

The total bill for the repair was around $2000. And remember I did all of the work myself so there was no labor charges. And the moral of the story is, it was my own stupidity that destroyed the five-speed transmission. If I would’ve broken out my owners manual and read through it when I first bought the vehicle I could have avoided this expensive repair.

Also when this transmission first started to make noise I had a second chance at saving the day and reading the owner’s manual. I would have seen a temperature chart and recommended fluid application that would indicate automatic transmission fluid was needed.

The 300ZX repairs that where required on this car over the years taught me a lot of lessons about Nissan in general. In fact I have a story posted on my other website that describes how I repaired the 300zx digital dash in this car. That story has a much happier ending. For the latest posts to this blog this next link takes you to the homepage from 300ZX manual transmission to car repair information.