Was checking my spark plugs today and saw that my #3 coil pack was significantly darker in color (the red bit of it) than the other three. The spark plug itself was in identical condition as the rest, it looked fine.



Is this normal? Something wrong with the coil perhaps? Anyone have any idea?

 

I recently replaced all my coil packs after having alot of "stutter" issues. The #2 was replaced by a dealership when i originally had a problem away from home. I replaced the other 3 myself and the #3 was also miscolored (much like in your picture). Since replacing the rest of the coil packs the stuttering has gone away. I do have 123,000 miles on the OD. Are you having engine stuttering- at speed -50-65mph or at idle? You may want to start with the # 3.

 

Car is at 37,000 and haven't noticed any stuttering. The coil pack was normal color at 29,000 when I last changed my spark plugs. Everything seems fine for now... but if there's any stuttering or misfires down the road this seems like the place to start.

 

Okay now I am finding there is some stuttering while the car isn't yet warmed up. From a cold start up to around 175-180 degrees F, the idle rpms will drop from 850 to 700-750 then jump back up to 850 in a split second. This happens every 5-10 seconds until the car is warmed up, at which point it stops. I'll be switching out the discolored coil pack and see if this issue goes away.