Guide to Replacing Spark Plugs

Organized spark plugs and wiresOrganized spark plugs and wires
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Yes replacing spark plugs is a great do it yourself auto repair. However, keep in mind that some engines make this more difficult than others. In the automobile maintenance video below you'll see how quickly this repair can be done in the driveway on many vehicles.

Before you jump in remember that spark plug replacement is not required as often on modern-day engines, thanks to precious metals like platinum and iridium. The parts cost more, but are serviced much less. In fact some auto repair shops claim that these plugs are putting them out of business.

I wrote an article on my blog about how spark plug maintenance effects both consumers and businesses alike. Check the owner's manual that came with the automobile for exact maintenance intervals on specific models and then move heaven and earth if necessary to stick to it. In many cases spark plugs will last for up to 60k for platinum and 100k for iridium tipped.

gear wrench spark plug socket

On the flip side of this is a vehicle with an illuminated check engine light and a code stored for a cylinder misfire. Just like anything automotive, isolated incidents of part failure are possible. If a cylinder starts to misfire due to a bad spark plug it might need replacing before its scheduled maintenance time. The Haynes repair manual video below also provides some good tips for replacing spark plugs.

A tip, that I would like to add to the procedure, is marking each spark plug with the cylinder number It was removed from. This way you can lay all of the spark plugs next to each other and compare their condition. It's nice to know what hole an odd looking one came out of for diagnostic reasons.

If one looks highly different than the others this may be an indication of a problem with that particular cylinder. All of the plugs should have nice even wear with a grayish color. If you have dark black deposits this would be an indication of a rich running condition.

Many things can cause a rich condition. One of the common things I see would be a leaky injector dripping gas not calculated by the computer. A clogged air filter can cause rich fuel mixtures as well.

If a spark plug has a white ashy deposit or an extremely worn electrode or ground strap, this would be an indication of a lean condition. One of the most common causes of a lean condition is a vacuum leak. So save the old plugs and examine them closely for insight on your engines overall health.

Spark Plug Maintenance Video

My General Opinion on Spark Plugs

I do think the how to video was well done. One thing that was not addressed was what kind of replacement spark plugs to use. There are many brands available for automotive enthusiasts to choose from. Bosch is one of those brands from Germany that has a great reputation.

Some of these replacement parts promise better performance or fuel economy. These statements should be backed up with testing data but its rarely included in the advertising. You will how ever find the factory installed parts on the assembly line are at least tested for temperature range and durability.

It's important for Car makers to avoid warranty claims and customer satisfaction issues. So the following is just my own personal opinion on the subject. I have tried many different brands and types and I can't say I noticed any difference in either fuel economy or a substantial boost in engine performance.

This is why when I perform this maintenance procedure I always use what was installed in the engine from the factory. Using this rule of thumb provides excellent long-lasting results that you can count on.

Installing the factory recommended parts ensures that the temperature range of the spark plug and also the required maintenance intervals of the components remains the same as the factory intended. There is nothing wrong with experimenting but be prepared for possible surprises such as reduced performance or increased fuel consumption.

If this happens be ready to install brand new factory recommended plugs. In the how to video they show a situation where a check engine light was set due to required maintenance of the spark plugs. They also showed how to repair the problem and reset the engine light.

The automotive scan tool they used was the Actron. This little tool is inexpensive and does a great job of resetting the check engine light and reading codes. This is why it is one of the most popular automotive scanners at the time of this writing.

You can click on the next link to read reviews both good and bad about the Actron scan tools. I think a feature worth holding out for is on screen code definitions. So you will not have to look them up in the supplied manual or stop what your doing to spin up a CD. The actron 9550 scan tool reviewed on that page can read the data stream for diagnosis purposes as well. But even if you just want to read and erase codes it is hard to beat this little auto scanner.

Sidebar: If you have a Ford Triton V8 with high miles, replacing spark plugs is a whole different ball game. Mainly because they didn't use the Permatex anti seize pictured directly above. I posted some information from the technical service bulletin about replacing Ford triton V8 spark plugs. Think about the next person (might be you) that will have to replace the plugs and use Anti-Seize.

Short videos are a great way to learn about automobiles. This is quickly becoming the most visited area of this Diy auto repair site. The next link will take you to the main page where you can view more car repair videos.

If you are looking for instant access to the exact procedure for replacing spark plugs on your specific vehicle I got you covered. This next page has a video about online Chevrolet repair manuals but applies to any model.

Learn about what else is covered on this website besides replacing spark plugs on the homepage. Find out more about the car mechanic that thinks some people can perform automotive maintenance and fix car problems at home with information from car repair websites.

If you are looking for some individual one-on-one auto repair help take a look at this next page. Mechanics that specialize in your vehicle and you are specific car problem are available to help you. This next link takes you to the auto repair help homepage.