[RickBullotta]

My '03 Coupe has been throwing these codes lately (I'll be taking it in tomorrow to have the dealer look at it). It occurs on startup when the engine is cold, usually after a "shuddering start" due to the wonderfully un-smooth CC launch, particularly in reverse. Usually P0300 (random misfire) and P0303, P0306, and P0308.

Anyone experiences something similar? Any resolution? My first thought was that the shaking on starting off was triggering a false detection, but now I'm not so certain. Clearly there is a power drop after this occurs.

I can start the car up warm generally without issues. I'm starting to get concerned about the groaning noises the car makes when taking its first few steps in the morning. Is this a normal sound? Sure doesn't seem like it should be...

 

[surfnirnava]

They can sometimes misfire if the engine has been started from cold for a few seconds and then turned off again (ie moving the car on the drive). The next time it is started, there is still fuel in the cylinders as the car hadn't warmed up previously. It splutters and misfires.

My car also went through a 'groaning' period where I thought the problem was with one of the two fuel pumps. It turned out to be a faulty filler cap causing pressure problems in the tank.

Tim

 

[RickBullotta]

First indication from the techs was a faulty fuel rail. My bet was on a fuel system/pump leak or EGR leak (occasional fuel odor), but I trust their judgement and will give it a go.

 

[04cambio]

These problems sound very similar to the problems I have been having for over a year. Last year I posted about random multiple cylinder misfires (P030,2,3,4,5,6,8), and someone suggested that I tighten my gas cap. That didn't work. I took it to the dealer, and they could not figure out the problem. It never occured to me that it may be a faulty gas cap. How did you figure out that was the problem? That would certainly be easy to fix.
My OBD II light went on and off intermittently and randomly last year, but this year it has stayed on constantly. The only thing that I think I could possibly correlate is full throttle. It seems to go on more often at maximum acceleration. There is also a definite increase in performance when the light is off.
I had a very rare groaning sound last year, but I don't know if it is related. Any ideas?
Thanks for the suggestions.
I live 2 hours from the dealership. Maybe I'll ask them to send me a new gas cap to see if that corrects the problem.
Tony

 

[surfnirnava]

I took mine to the dealer and pressed them to deal with it urgently as the following week I was driving through Europe to visit the factory! While with the engineers, the car started groaning again and one of the mechanics simply walked past and said "faulty filler cap". They changed it and voila - fixed. Apparaently it caused pressure problems in the tank.
Fortunately I am only 45mins from the dealer.

Tim

 

[RickBullotta]

The fuel rails were replaced under warranty and the code(s) were reset, so I'll wait-and-see for now. I think I'll have the fuel filler cap replaced on my dime "just in case". Also, the groaning I hear sound more clutch related, but time will tell. All running well now!

 

[barbuckle]

I'm starting to get concerned about the groaning noises the car makes when taking its first few steps in the morning. Is this a normal sound? Sure doesn't seem like it should be...

There is a known issue when engaging first gear esp. when cold. My dealer tells me this is has happened with with some CC clutches. They are replacing the clutch in my car under warranty. I suggest you ask your dealer to do likewise.