Iridium Spark Plug

Can increased spark plug maintenance intervals put people out of work? We live in a changing world and sometimes we don’t realize what a big impact seemingly small changes have in our lives. When I got into the auto repair business there was plenty of work to go around. This has changed drastically over the last 2 decades. Maintenance intervals have increased and the car doesn’t need as much attention as it use to.

Today I’m going to talk about spark plug maintenance in particular but you could also add to the list of things that changed the automotive maintenance business, synthetic engine oil, extended life anti-freeze, new transmission technology requiring less fluid and filter changes and direct ignition systems that did away with the distributor cap and rotor.

But let’s talk about spark plugs. When you get right down to it a spark plug provides an electrical lightning bolt that ignites the air fuel mixture in the combustion chamber on command. Voltage surges supplied from the coil travel down spark plug wires to the correct plug. The voltage jumps across two specific points, being from the electrode to the ground strap.

Spark-Plug Diagram

This miniature thunder and lightning system will still need maintenance over time but nothing like it use to be. In fact if you replace your vehicle every 3 to 5 years you might miss a scheduled spark plug maintenance altogether. So how can this be and what did they do to change the maintenance interval so drastically.

It all boils down to the materials that the electrode is made of. This has the largest overall effect on the longevity, power and efficiency of the plug. The construction and shape of the tip of the electrode are also important. The electrodes of the standard spark-plug that was common in the 80s were made with copper and nickel alloy.

They did a good job of conducting electricity and providing an excellent spark but they would wear down over time. This is where the idea came to use platinum electrodes on spark plugs as it did a good job of conducting electricity but lasted much longer. When platinum spark-plugs came on the scene they would last till about 5 years or 60,000 miles as compared to 35,000 miles of a standard copper nickel alloy electrode plug. When that happened we began to see customers less often at the shop.

But that wasn’t the end of it. Iridium spark plugs came on the scene and provided even longer electrode life then platinum tipped plugs. Iridium is a precious silver white metal and one of the densest materials found on Earth. It is common for these types of spark plugs to have maintenance requirements at 100,000 miles or 10 years whichever comes first.

Long-lasting spark plugs mean people need me less

platinum spark plug

There is no question that the car is a different animal than it was just a few years ago. Although I could cite many other examples the spark-plug maintenance interval makes my point. What made me write about this today? My ex-girlfriend stopped by and asked if her car needed a tune-up.

I looked in her owner’s manual and it said that her 2003 Toyota Corolla had iridium spark plugs installed and that maintenance was not required for 10 years 100,000 miles. A nice little side job went rolling down the street with the news. When I got into the auto repair business it was replacing spark plugs that kept a lot of shops going. The customer was conditioned to think that replacing the spark plugs better known as a tune-up could solve a lot of common problems.

Therefore when a driver took a vehicle in for service if the shop told them a tune-up was required, not only was it believable but it was probable. The recommended maintenance interval from the vehicle manufacturers back in the 80s was to replace them every 3 years or 35,000 miles now it’s 10 years 100,000 miles. In the long run this will most likely mean that less auto repair shops will be required going forward as maintenance intervals increase.

In my town alone, five auto repair shops have closed up in the last year. Two of them where major franchises that had strong advertising budgets. The world changes and so does the auto repair business and I guess there’s not much we can do about it. Want to put more mechanics out of work? Here is a video showing how to replace spark plugs yourself. Feel free to leave a comment at the bottom or you can return to the homepage from this next link to read more articles on the auto repair information blog.

Denso Spark Plugs

Replacing spark plugs has always been a favorite task of do-it-yourself auto mechanics. The interesting thing about this maintenance operation is that on some vehicles it is fun and easy.

On other automobiles the task is extremely difficult and sometimes the path of success is plagued with extreme problems that could lead to pulling the cylinder head.

Sometimes when spark plugs are removed from a cylinder head the threads will have traces of metal on them.

Each spark plug removed should be numbered with the cylinder it was removed from and inspected thoroughly for this type of thread damage. This type of car problem happens more often on engines that use aluminum cylinder heads.

If you run into this problem when performing your own sparkplug maintenance it is highly recommended to correct the condition before reinstalling the plugs. Patience and care at this point can save you from major auto repairs down the road.

Bosch Spark Plugs

If you force the plug back into the bore, or they become tight before they bottom the likelihood that the plug will leak or blow out increases.

If compression forces the plug out of the hole while the engine is running, a large amount of damage can occur to the cylinder head.

If this happens to you note that the head should be removed and checked for damage by a machine shop.

The end result may include and require replacement. It is also safe to say when this happens it will scare the hell out of the driver when it blows out.

Replacing spark plug tips

The number one rule for me is to never try replacing spark plugs when the engine is hot. If you remove them on a hot cylinder head The threaded holes can become egg shaped as the cylinder head cools without the sparkplugs to hold or retain the shape.

The number 2 rule for me is that replacing spark plugs should only be done when recommended by the manufacturer or if a plug happens to fail which is very rare.

Just a few years ago plug maintenance was recommended about every 30,000 miles. Now modern platinum plugs can go as far as 100,000 miles before maintenance is recommended (check your owners manual for recommendations).

Spark plug thread chaser

When installing sparkplugs if the plugs cannot be installed easily by hand the threads in the cylinder head may need to be cleaned with a thread-chasing tap.

There are special taps for spark plug holes simply called spark plug chasers. You have to be really careful not to cross thread the new plugs when you’re working with aluminum cylinder heads.

It is also recommended that do-it-yourself car mechanics tighten the plugs with a torque wrench using the correct spark plug socket with out a universal joint if possible.

The following affiliate link will take you to amazons website were you can get special spark plug tools like thread chasers, wire boot pullers, replacement thread installers, torque wrenches and of course inexpensive replacement spark plugs.

Always follow the vehicle manufacturer specifications in your auto service manual.

Recap of the #1 rule: In most cases, automotive manufacturers agree with me that this car maintenance operation should never take place on even a warm engine. Let the engine cool down to the ambient surrounding temperature before you begin your spark plug replacement.