Your car needs a tune up? Why?
When it comes to vehicle maintenance I can’t think of a more misused term than tune up. If I were to ask ten different people how they define an engine tune, I would probably get ten different answers.
For the sake of this topic I am going to assume most car owners think of a tune up as replacing the engine spark plugs as well as the air and fuel filters. Some may also believe this includes any adjustments that can be made to the engine to restore the performance and economy to optimum levels.
Unfortunately asking a repair shop for an engine tune is akin to asking them to have their way with your wallet. The definition of an engine tune differs from garage to garage much the same as it does from car owner to car owner.
Up until the mid 1980s and most cars still used moving parts to deliver spark and fuel to the engine. And, these parts did indeed wear and require periodic replacement or adjustment. At that time spark plugs were made of copper tips and lasted somewhere around 30,000 miles. The spark plugs could be removed, cleaned, and the gap adjusted if worn but it was often more cost effective to replace them. Filters also required frequent replacement which was also part of an engine tune at that time.
Newer cars use no moving parts to deliver spark and fuel to the engine. Thus, there are no adjustments to be made as part of routine maintenance. Spark plugs are now designed with platinum or iridium tips and will generally last for 100,000 miles. Air and fuel filters do not require replacement with the same frequency they did just 30 years ago.
In an earlier post I suggested digging your owner’s manual out of the glove box and becoming very familiar with it. Inside the owner’s manual is a list of maintenance recommendations that includes specific intervals for the air and fuel filters as well as the spark plugs. Most maintenance schedules are divided into two intervals; severe and normal driving conditions. For most car owners normal driving conditions apply. However I live in the hot southern California desert where hot and dusty weather make my conditions a little more severe.
If you don’t have the owner’s manual anymore I recommend going to the local auto parts store and buying a paper back copy of the repair manual for your specific vehicle which also includes the manufacturer’s service schedules. This is a good investment even if you have the owner’s manual. Not only does the repair manual include the service recommendations it also explains how to change the filters and spark plugs yourself.
So what do you do when the car seems to be a little under the weather? Throw a bunch of filters and spark plugs into the engine and hope for the best, and call it a tune up? It may or may not solve the problem. It may also be a terrible waste of money. Platinum tipped spark plugs are not cheap. Filters can also put a significant dent in your pocket depending on what you drive. However this is where you really need to look at the maintenance intervals listed for your particular car and decide whether or not it needs new filters and spark plugs. A simple fuel filter may solve the problem if it hasn’t been changed within the recommended interval. There would be no reason to install new spark plugs if the engine is well under the mileage recommendations. To put it another way the service schedule for my particular car lists a fuel filter replacement at 20,000 miles, and the spark plugs at 100,000 miles. If I follow the recommended schedule I would replace the fuel filter four times before replacing the spark plugs once.
There are additional considerations that I plan to cover in future posts. Fuel injector cleaning. Is that part of a scheduled service? Will it make the car run at peak performance? I plan to look into that and other snake oil recommendations.
In the mean time stick with what is recommended by the manufacturer for the best performance and reliability from your car.
Your Pocket Mechanic 