When i am on cruise or holding a certain speed, the RPM gauge bounces about 200RPM. you can feel it speed up and slow down constantly while you are driving.

Once the engine is really warmed up, it tends to stop.

any idea what sensor might cause this?

EDIT : Sorry just noticed a similar thread. please close

 

I have the same problem. A lot of people seem to have this issue. I was told by someone and confirmed from several other forums that it's caused by a faulty torque converter. There's even a youtube video of someone driving and showing the RPM fluctuating under low throttle and the comments even say it's the torque converter.

I took my car to Pfaff a few days ago and they did some service under a recall (fuel pressure related), but that did not fix the problem whatsoever. So now I have to go back, which is very annoying, especially when I told them to check the torque converter and they never did.

I'll report back when/if I get it fixed.

 

Here was my update in the other thread.

https://www.audiforum.ca/a4-b7-typ-8e-8h-2005%962008-77/engine-pulsing-when-cold-67104/page4/

Also, As of 3 days ago, my transmission started leaking oil. I have an appt. on wednesday to get it looked at.

This is not going to be cheap, i can feel it.

 

Do you have any warranty? I'm guessing it would be a lot cheaper going to an independent shop.

 

No warranty. 06 With 155,000

Its not going to the dealer. its going to a trusted Audi/VW mechanic

 

Hello, sorry for digging up this thread, but I have exact same issue. Bought a4 2007 and it turned out the rpm bounces. Checked underbody and found some fluid dripping.
What did it turn out to be the issue?Was it the torque converter?