A couple of weeks ago I took my car in for the annual inspection. When I went to pick it up, the mechanic told me that I need new struts. He said he could tell because of ‘cupping’ on the tires. I didn’t ask him to show me what he meant, but looked at them later and don’t see anything usual about them – wear looks completely even. Last week, I was on a long drive when the check engine light came on about an hour into the drive. The next day, I was using the car to run short errands and the light, which had still been on from the night before, when off towards the end of my using the car. Since then, I have only used the car for very short distances and the check engine light has never come back on. I have some longer drives coming up in the future and am afraid that the light is going to come back on during those drives. My questions are: 1) Could the struts and the check engine light be related?; 2) Would a mechanic be able to read why the check engine light had been on, even if it is not on when I take it to the shop?; 3) Does anyone have any idea why a check engine light would come on then turn back off? – it’s not the gas cap, I always put it back on tight 4) Is there another way to evaluate whether I need new struts? The car is a 2002 Mazda Protege5 with 160,000 miles. I think the road noise might have increase, but I can’t be sure as the car has always been sort of loud. Thanks!
Cupping is NOT easy to see visually.
The problem with the check engine light could be anything. You need to get it read. When it comes back on…head over to ADAP or Advanced auto…they’ll read the codes for free…
I’ll give this one a shot…feel free to correct as appropriate…
CEL first…it seems easier to me. Yes, any good mechanic with the appropriate tools can read the history. Any number of things can set that thing off (or turn it on). Some of them will indeed fix themselves, and the example that comes to mind is some sort of bad stuff in your fuel. It can cause misfires, which can set off the CEL, but once you burn through it, the engine stops misfiring, and the check condition goes away. You should still have it checked, though.
Struts: They’re simply springs and shock absorbers in the same unit. Normally, shops will simply change out the unit if they’re bad. They can be rebuilt, and for the home mechanic (with the right tools and knowledge), this is the cheaper way to go. You can check the operation like any other shock: Bounce one corner of the car. If the car goes down, and comes back up and stops smoothly (e.g. no bouncing), then they’re probably not bad. While that’s not definitive, it is indicative.
“Cupping” on the tires is normally (not always) associated with bad alignment. If you look closely at the tires (both inside and outside tracks), you may see one side of the rubber “blocks” sitting slightly higher than the other. Sort of like they’re all kind of pushed a bit the same way. That’s cupping (sorry, my descriptions don’t always make the grade). It’s possible there is somethig wrong with your struts (or one of them) and it’s causing an alignment problem.
The only way to tell for sure is to have a reputable garage check it out. Most of the inspection people I’ve run across can barely tell the difference between a headlight and a golfball. They run down a checklist…horn, works, lights, came on, tires…yep, 4. Clear the checklist, and you get your inspection certificate. I’m not saying they’re all this way, but it’s possible. I’ve seen vehicles on the road (even rolling out of the inspection station), with recent inspections, that belong in the junkyard.
I guess this all boils down to: get another opinion, and from someone you trust. But tell them what you were told, and have them look there specifically.
CEL. The CEL does not come on when a fault is detected the first time. It stores the code as a pending code. This will disappear unless the fault is detected on the next drive. If it is detected on two drives in a row, the light will come on. Now if it is not detected for three drives in a row, the light goes out, but the code remains in memory for about 10 more drive cycles.
The code may still be in memory. If the code first came on after filling the gas tank, you may have overfilled the gas tank and saturated the purge valve or charcoal canister. If you stop on the first click from now on, you wont see that code again.
The struts are not connected to the OBDII system, in other words, no codes for struts. If cupping of the tires is serious enough, you will be able to see it. Its pretty obvious to most people when it occurs. Most tire stores have a chart of different types of tire wear. Everyone should look at one of these and then check the wear pattern on their tires frequently, at least at every oil change.
Thanks for all the responses!