A6 2.7t stuttering at high RPMs

**IzeBerg** · 06-14-2008 07:23 AM

I need some advice.
This past week i was coming home from work and i went to accelerate up the on ramp on the interstate and when i had my car pretty much floored in 3rd gear and i got up to around 3500rpms it started stuttering really hard and the check engine light flashed....i let off and shifted down to 4th and the light when off and it started to pull again....i experimented a few times and almost every time in 3rd it would stutter once i got up around the same RPMs....but if i gradually accelerate i can redline it with not stutter...only does it when i have it pretty much floored....i thought maybe it wasn't getting enough fuel...i replaced the fuel filter this weekend (which looked like it was the original filter that came on the car and i'm at about 80k miles now) but it is still stuttering....so i'm thinking it might be the injectors or something related to the fuel.

if anyone has any other advice i'd love to hear it.

oh and this was with the APR 93 octane chip which has been on for about a month now (and i have only ran 93 octance since i've had the car for over a year now)....and i'm putting it back on stock settings today and running it for ahwile to see if it will stutter in stock mode

**volks88** · 06-14-2008 07:38 AM

is this only in 3rd gear?

**IzeBerg** · 06-14-2008 08:02 AM

Originally Posted by volks88

is this only in 3rd gear?

no it does it in 1st and 2nd but it doesnt seem as bad in those gears...it just hesitates around that RPM range then kicks back into running fine....in 3rd it seems like it is almost spitting and sputtering if i keep accelerating....but like i said this isnt every single time i run it but most the time.

**volks88** · 06-14-2008 08:29 AM

ok so how is it in 5th? if you start at 3000 rpm and stomp it will it feel like its going to build boost and then miss and sputter causing it to go limp mode? now if you do the same test but this time gradually roll the throttle on can you get it past the hesitation spot and build boost until redline without hesitation?

**Daft** · 06-14-2008 10:39 AM

Since it's only under acceleration, I'd be willing to bet that it's either plugs or one or more coils going bad.

I had to replace two of my coils within two days of the APR software going on my car last year. Only a month or so later, I replaced the other 4 because they were failing too.

If you really want to pinpoint the exact issue, you would look at the error codes in VAG-COM and see which cylinders are misfiring. Then you can watch that cylinder individually while you drive and see the actual misfires.

If you are able to pinpoint the cylinder that is acting up, you can swap the coil pack to another location and put a known good coil in that spot. Repeat the test and see if the misfires have moved. If they do, you have determined that the coil was bad.

If the misfires don't move to another cylinder, replace the spark plugs.

BTW, now is a good time to get that boost gauge plumbed and working. It would be ideal to see how boost is registering under WOT.

**IzeBerg** · 06-14-2008 01:50 PM

brett thanks for the advice....i was considering replacing the plugs thinking it might be the problem...think i might just replace the coils too while i'm at it....can't hurt to replace them since i'm sure they have never been.