RPM Surge - Shifting at a Stop

[STL21]

I have an annoying RPM surge that happens every time I stop (see videos). It varies in how bad the rpm's surge but it's between 200-500 rpm's each time. It happens after applying the brake and the car shifts from 2nd to 1st. A similar feeling happens when shifting from Drive to Reverse and Reverse to Drive. I can't find any correlation between outside temp, engine temp, slow/fast stop or anything that would point me to an issue. There was no one event when this started but noticed it one day and has not gone away.

Any one have an idea what could be causing this? Appreciate any ideas or feedback.



https://youtu.be/DVrsx77ImcU


https://youtu.be/Et8EK0SSzXs




2016 S6 - 50k miles, SRM Intake, SRM Rs7 Turbos, DS1 Tune.

[Alabama]

Scan for codes?

[mdelmonico]

My S7 did a very similar thing. No codes just idle jumping like yours. It ended up being the PCV.

The suction was strong that I couldn't remove the oil cap when the car was idling.

Sent from my SM-N975U using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)

[STL21]

Correct, no VAG-COM codes. When you say PCV, are you meaning the oil separator itself? And is that covered under the extended Audi PCV warranty i've heard about on here? That was changed last month after my turbos failed and the issue happened before that.

Similar to swap to this post https://www.audiworld.com/forums/s6-c7-platform-discussion-199/pcv-valve-replacement-diy-2921782/

[mdelmonico]

Yes, it is the oil separator as well. I changed mine myself. I didn't want to wait for Audi to diagnose and fix the issue. I also wasn't sure it would be covered since it was not making the high pitch squeal that is explained in the TSB.

You could try and bring it back to Audi and see if they can diagnose the issue. But I would make sure that the Oil Separator/PCV was replaced.

You could start the and try pulling the oil cap off. If it is very difficult to get off then that is the problem.

Sent from my SM-N975U using Audizine Forum mobile app (http://r.tapatalk.com/byo?rid=87676)

[TheChief]

I'm having a similar although slightly less intense rpm surge when coming to a stop after driving. The thing is that I already had my oil seperator/PCV taken care of and turbo screen replaced less than 5k miles ago. So I really hope it's not that again.

[zcd2.7t]

Mine always did that - “it’s a feature, not a glitch”.

You get used to it over time.

Yes, seriously.

[IHave2Turbos]

my totally unqualified theory is that the car tries to stay in 2nd to save gas if you are only rolling to a stop. once some threshold is met it downshifts into first and this is what you are feeling. happy to be proven wrong by someone with actual answer but mine does this too and always has

[Cmargot1221]

Hi all! I have the exact same issue in my 2016 Audi s6. It only happens when my AC is on though. Any advice? Has this issue been fixed in your S6?

- - - Updated - - -

Hi all! I have the exact same issue in my 2016 Audi s6. It only happens when my AC is on though. Any advice? Has this issue been fixed in your S6?

[zcd2.7t]

Hi all! I have the exact same issue in my 2016 Audi s6. It only happens when my AC is on though. Any advice? Has this issue been fixed in your S6?

There’s no fix. Seriously.

[plai7778]

There’s no fix. Seriously.

18 b9 S5 same issue when I brake as it downshifts to each gear I get an rpm jolt of 100-200 rpm each gear down

[damnbiker]

I had this on my 30k mile 2016 S7, mainly when cold. It was enough to move the car after I had brakes applied at a stop.

After I got the DSG fluid changed and re-adapted by dealer (first DSG change since new), its much less pronounced and barely noticeable now.