Hey guys,

Bought a warrantied '05 coupe (6-speed) from a GMC dealer, here in Canada - it's covered for the next three months by their Optimum warranty, which is about as close to bumper-to-bumper as one will get on a seven year old car. The car received a highly detailed inspection, which it passed with flying colours; all it appears to have a problem with are wearing-out tires and this apparent tappet noise and possibly related minor issues.

The good news? The car has only 21,000 KM's - only 13,000 miles in seven years. Remarkably low. During much of this time, I have to surmise from the shockingly low mileage on the odometer (which was verified true) that the car wasn't driven much at all. The car still smells new. The paint is close to immaculate. The engine is virtually spotless. The car drives very, very well. Overall, I have little to complain about.

That said, to the complaint(s)!

Now, my father (who also posts on these boards) has an '04 with twice the mileage of my car, but his motor is whisper-quiet. My motor, by comparison, is noticeably 'ticky' at idle, and loud enough below 3000 RPM to be noticeable (mostly between 2500-3000 RPM). Interestingly enough, the ticking cannot be heard above about 3K RPM, but that may simply be because engine noise in general drowns it out! Needless to say, on a low mileage motor, and with Benz block at that, I expect something quieter than my '81 DeLorean, and yet the Crossfire isn't. It's not abominably loud, but it's noticeably louder than a block of this quality and mileage should be.

My best guess as to the tappet noise (if that's what it is) is due to stuck/seized/goopy lifters as a result of the car being subjected to prolonged periods of sitting around, and therefore lengthy stretches of time within which no oil was being passed through the lifters, permitting them (I'm gonna be technical here) to 'crap out'. To my mind, if that's the case, I take it I should be telling GM to replace the lifters.

On a possibly related problem, I appear to be having an intermittent missing problem at idle (not too rough, though), and the car shuts down rather roughly as well - a bit of vibration, if you will, when the ignition is turned off.

I'm pretty good mechanically, but really only with old tech; my DeLorean, which I've mechanically worked on in great detail, is a simplistic old SOHC V6 without any lifters whatsoever, and my previous cars were all old push-rod V8's (mostly Corvettes). I'm a little out of my league on a relatively 'new technology' German engine, so my guesses are just that - guesses - and I would appreciate any guidance that you guys can share.

If anyone can nod in agreement at my guess, tell me I'm more than likely wrong, or suggest that the idle/shut-down/ticking are related, please let me know. The car is heading to the GMC dealership this Wednesday for servicing, and I'd like to go fore-armed with as much knowledge as possible, as I'm willing to wager that few (if any) of their techs have ever worked on a Crossfire, certified and professional though they may be.

Cheers.