[GreaseMonkey]

Hi everyone, just want to brainstorm about my current rough idle and occassional hesitation under load. The rough idle comes and goes, one day it feels like the car is sitting right over an earthquake, the next it feels fine. After resetting adaptations the car feels brand new for a few days, but the roughness will come back eventually. No trouble codes or misfire codes recorded.

Car has roughly 77,000 miles.

1) Pulled the plugs yesterday, they look perfect, no gasoline smell from leaky injectors. (Injectors were replaced with index 12 last year)
2) All 4 O2s were replaced around May. I had serious idle problems when those actually failed, this feels similar, but not nearly as bad.
3) HPFP went out a couple years ago, symptoms feel similar, but I have not lost power or thrown any trouble codes.
4) Coils are original
5) Walnut blast was done around 40,000 miles ago
6) Occasional puffs of white (slight hint of blue smoke), usually after the car has sat idling for 5-10 minutes or after multiple shorts trips running errands around town. I believe I have oil leaking from the turbo seals or turbo oil lines (this is not the main issue, just giving full background)

I believe the issue is most likely the valves needing another walnut blast, but I want to find out if it is likely the cheaper and easier fix of replacing the coils first. Any other thoughts would be appreciated, thanks!

[Jklad]

Originally Posted by GreaseMonkey

Hi everyone, just want to brainstorm about my current rough idle and occassional hesitation under load. The rough idle comes and goes, one day it feels like the car is sitting right over an earthquake, the next it feels fine. After resetting adaptations the car feels brand new for a few days, but the roughness will come back eventually. No trouble codes or misfire codes recorded.

Car has roughly 77,000 miles.

1) Pulled the plugs yesterday, they look perfect, no gasoline smell from leaky injectors. (Injectors were replaced with index 12 last year)
2) All 4 O2s were replaced around May. I had serious idle problems when those actually failed, this feels similar, but not nearly as bad.
3) HPFP went out a couple years ago, symptoms feel similar, but I have not lost power or thrown any trouble codes.
4) Coils are original
5) Walnut blast was done around 40,000 miles ago
6) Occasional puffs of white (slight hint of blue smoke), usually after the car has sat idling for 5-10 minutes or after multiple shorts trips running errands around town. I believe I have oil leaking from the turbo seals or turbo oil lines (this is not the main issue, just giving full background)

I believe the issue is most likely the valves needing another walnut blast, but I want to find out if it is likely the cheaper and easier fix of replacing the coils first. Any other thoughts would be appreciated, thanks!

I would get a walnut blast and simply replace coils and plugs to rule those out, plus you seem to be due for it anyways and they are cheap and easy to do.

[GreaseMonkey]

Plugs are about 2 months old, I changed them when I replaced the o2 sensors.

Coils and Walnut Blast are the two items I suspect will solve the issue, I was just hoping to get a consensus on which is most likely the problem.

Thanks

[MichaelP]

Have you checked your valve cover and pvc? I was having a rough idle and occasional smoking and the culprit was a cracked valve cover

[335e92tx]

Reset adaptions (id include throttle) and see if anything changes. Can you log event?