When a customer tells me that they need a tune up, my first question is, "Why?". It may seem a little rude at first, but it's because I have had some bad experiences because I didn't ask. Most people don't start looking into getting a tune up until something is wrong with their vehicle. In most cases, a tune up won't fix the problem and the customer is angry because they spent money for it. So by asking, I can actually help my customer save money.
In most cases, a check engine light does not mean that you need a tune up. This is a common misconception. At times, there can be misfires which are caused by bad spark plugs. When that happens, the vehicle will run poorly as well as causing a check engine light. However, 90% of check engine lights are for other reasons. So to just assume a tune up is wrong about 90% of the time.
Tune ups should be done for maintenance before a problem surfaces. The definition of tune up can be (and usually is) greatly debated.
So that pesky check engine light is on again and they keep telling you its your 'EGR' system. They say this and that, but honestly, it tends to be a bit confusing. Here's the scoop, it's designed to reduce tailpipe emissions.
Okay, they already told you that and it doesn't help. Flashback to pictures of cars from an era where they would puke black smoke from the tailpipe. Standards were set on car manufacturers to reduce that...a lot. So the first and most obvious plan was to pull some of that back through the engine and burn it again. Unfortunately, not all of the fuel that goes into your engine gets burnt. Some of your precious dollars were flying out of the tailpipe. By burning the same air a couple times, more material was burnt up and fuel economy increased. Both are big bonuses.
The problem is, already burnt and sooty air is pretty dirty. These systems get filled with this soot and before long the valves and tubes get clogged or won't work. The car tells the valves to open at certain times and it just sticks because its all...well, sticky. This valve is called an 'EGR valve'. This is the most common point of failure.
As engine efficiencies increase through new technologies, less waste flows through the exhaust air. Newer systems tend to foul out less often, but ultimately, burnt air is dirty and will cause problems.
If you have any question or comments, please let us know. Have a check engine light? We scan at your door for $35.00.
Erik and Jennifer are the owner/operators of Mobile Service Pros. We enjoy working with our customers and community.