rough acceleration, no cel, can't tell what it is!

[judunty84]

*EDIT* rough acceleration, no cel, STILL can't tell what it is!

I have a 2007 FSI with an APR stage 1 flash with 69,xxx miles on the clock. Everything else motor wise is stock. So for the past month or so under light load in low rpm i have gotten a few little hitches during acceleration, but nothing really concerning.

Fast forward to today and it has gotten worse. When the motor is under load in mid rpm's there is quite a bit of stuttering. It is strange because my initial reaction was that the clutch was going bad because I can hear the motor boost and the boost gauge seems normal. Then I starting straying away from the clutch idea because the rpm's don't seem to jump as if the clutch was slipping. The strange thing is as it builds boost and hits higher rpm's it clears up and runs fine. It seems like from 2000 rpm to say 4500 or so is the worst.

It is not showing a CEL and unfortunately i don't have access to VAGCOM. Here is a list of ideas but I don't want to start spending $ on parts until i have a good direction...

-clutch going bad
-fueling issue (cam follower was changed for the second time at 60k
-plugs (were changed 30k ago at the 40k tune up)
-coils (were changed by dealer under TSB)
-something else and i have no idea!

it is just weird to me if it is an engine related issue and there is no CEL on. That is why i initially thought clutch.

Any advice?

Thanks!

 

[Rajini98]

1. check PCV

2. check cam follower.

both can cause engine problems without throwing a CEL

 

[darkorb]

cam follower

 

[judunty84]

Hmm ok I'll check the cam follower but I am hoping that's not it with only 9,000 miles on the current one.

 

[judunty84]

I changed my oil yesteday and decided to check the cam follower and PCV as suggested. Both looked fine. The cam follower has about 10k on it and i have been changing it every 30k. The coating was starting to show some wear but looked good.

The PCV looked good as well. There is no oil being pushed back by the filler or anywhere else. The is a small trace of oil on the edges of the PCV which I would assume is normal. The bottom of the PCV gasket was a little dirty but no leaks or build up.

I pulled the spark plugs and they were a white like the originals when I pulled them but they didnt look extremely worn.

I had it scanned at AutoZone and there were no codes/no CEL.

Would a bad fuel filter be a viable cause?

Thanks for any more advice.

 

[vagike]

if you didn't use a feeler gauge to check the gap on your plugs, the you can accurately comment on how worn the plugs are.

I am leaning toward plugs. My plugs lasted me ~70000kms, or ~43000 miles, on APR stage 1. I had the exact same issues. When I pulled my plugs i had a 1.2 mm gap, or ~0.047". Spec is .7mm, or ~0.028".

 

[xatnys360]

Copper plugs are cheap and so are fuel filters - replace them and you'll know for sure if either had anything to do with your issues. What DV are you running?

 

[FiXXXerX]

Would be weird to not have a CEL... But I'm gonna go Injectors on this one.

Almost same identical symptoms when my #2 went. After they replaced #2, #4 went and they ended up replacing all of my injectors and CP #2. Problem resolved.

 

[eurocars]

Would be weird to not have a CEL... But I'm gonna go Injectors on this one.

Almost same identical symptoms when my #2 went. After they replaced #2, #4 went and they ended up replacing all of my injectors and CP #2. Problem resolved.

how was it diagnosed, or did it quit completely?

 

[FiXXXerX]

My car would stutter during acceleration in the mid-rpm range, then clear out towards the upper rpm-range. I drove it like that for a day or so and the CEL came on for a sec then went away even though the problem remained.

Brought it to the dealer, me and the tech took the car out and beat on it and 'Bam' injector blew and was stuck full open. EPC light came on, car went into limp mode until we made it back. CEL was checked and Injector 2 was the culprit. They replaced it, then took the car back out again, and about 2 miles into the test injector #4 failed. they said screw it and replaced the remaining injectors and the problem was resolved.

That the gist of it...

 

[judunty84]

Thanks for the suggestions. I am still unsure of the issue. I pulled the DV tonight and I am running the revision "C" DV and everything looked fine. No holes, oil, or sticking on the sliding action. I will pull the spark plugs and check the gaps. If that is not it I will change the fuel filter.

I hope it is not injectors but I would think that I should have a CEL or a code by now as I have been driving on it for a couple weeks. SOOOOO FRUSTRATING!