I've had some issues with a recurring check engine light in the ~year I've had my car. For reference, I have an '04 40th AE.

The car is under CPO warranty for another year so I've been basically "following the dealerships recommendations".

Error was "random misfires" the first few times. First time was a month after I got the car and I feared the worst and brought it to the closest dealership. They sold me a fuel additive and said it was "bad gas". I haven't gone back there.

Next time (different dealership) the service advisor asked if I had just bought gas. I had (less than 24 hours ago) and he said it was PROBABLY just air in the system and not to worry about it.

Less than a week later I was back at the dealer and dropped the car off. They had it a day, said the code cleared and there was no issue.

The next time I just drove to AutoZone and had them read the code and reset it.

It happened yet again and I dropped a comment to the service manager. That got the diagnosis to be needing new spark plugs. We "discussed" the charges on this one and came to an agreement since plugs aren't warranty work.

The next visit the code was apparently different but they referenced a "Porsche procedure" that said the first step was to remove and reset the car's computer (I refer to them as ECU's...he called it something else). I was told that this should fix it but not to be surprised if it came back on...then they would move to "the next step" in the list.

Naturally it came back on again. This time the replaced the flywheel (this was apparently the next step). I got the car back last Friday. Clutch feels totally different but the car is driving great.

Having said all that...does this diagnostic process (reset computer, replace flywheel) sounds familiar to anyone? I am basically letting them do what they say is necessary as it's warranty work and I'm not paying (from what I can tell replacing the flywheel isn't cheap).

I have about a year left on the warranty and I am trying to gauge if this is a "problem car" that I should bail on or if it's just a logical progression to track a gremlin. :-)

Thoughts?

Thanks in advance!

 

Yeah it's about $2,000 to replace a flywheel & they do wear out so I would say you are ahead at this point. If you get another misfire code, I would start a log of the history & go back to the dealer doing the "steps"
Porsche ECU is called DME.

 

They replaced the flywheel in response to misfire codes? There must be a flowchart for this - it would be awesome to see.

My Boxster only showed misfire codes twice - both of them were when my fuel tank was very, very low. So that diagnosis sounds more rational to me than the flywheel.

Good luck - and please post the final diagnosis.

 

I am by no means a mechanic, but I'm curious how "misfires" equate to flywheels...but what do I know. GL, I hope you get everything worked out, sooner than later, and while under CPO.

Cheers,

DS

 

The relucter "trigger" wheel for the crankshaft position sensor is part of the flywheel, if it's damaged slightly (bent, rusted) it could be a contrbuter. Or if the flywheel dual mass springback is worn it could cause a misfire.

 

Sorry, should have clarified...the misfire code was supposedly resolved by swapping the plugs. When the initiated this "process" there was apparently a new code but I didn't get any detail. First step was to reset the DME...then the flywheel. Hopefully I won't find out what the next step is.

 

First find out what this new code is. Otherwise there is no point guessing why the flywheel was replaced.

 

The tech should have noted the error code on the repair invoice.

Also, the repair can't be considered complete when an error code appears (unless it was something related to say a power disconnect...). Whenever I've had my cars in for repair the invoice always states something to the effect the tech road tested the car and observed no issues and the car is performing to Porsche standards. If it said got XYZ error code I'd send the car back quicker than a burnt steak.

If the misfires went away with a "plug swap" the likely problem was not the plugs but the coils, one at least, that was not properly connected to the engine wiring harness.

You have to stay on top of this and see it through. Do not put off taking the car back if it is not right. If any repairs are done the warranty on them expires when the CPO warranty expires.

Besides you can't enjoy the car with the CEL coming on all the time. Tell the GM that and remind him he oversees a Porsche dealership with factory trained techs and the have a factory full of support people behind them.

If he can't see the car fixed and soon and to your satisfaction tell him one reason you bought the car was the highly touted service and so far you ain't seen any.

Make a vague comment that you wonder if this doesn't make you a victim of consumer fraud.

Be sure you note on the work order the fact the CEL is on again and get copies to have in case this goes on past warranty. You want it clear this issue was present before the warranty expired and you expect it to be resolved even if the warranty has expired. If not then suggest you were being stalled until the warranty expired so dealer didn't have to fix the car. Fraud again.