ACLdestroyer

When I am on the interstate cruising at a steady speed my RPMs occasionaly pulse up and down about 100 rpms. It is quite obvious and quite annoying. Car surges over and over and over.

Car is a 2010 A4 Avant.

Ryan1524

Go to the dealer. That is not normal.

BMWBig6

I vote normal behavior. I bet it's the torque converter locking and unlocking to maintain the specified cruising speed. But I have been wrong before...

Art234

I have a similar issue on the highway or mildly accelerating-in 5th gear not 6th. I get about a 200 rpm fluctuation and you can feel the car surging. I thought I read about this somewhere before-the dealer cleaned the throttle body but didn't fix the problem.

I think the fix has something to do with reprogramming the turbocharger control in the computer.

jd_cincy

Same issue here, posted the same thing a few months ago. It happens around 45mph, but is the most noticeable on the highway with cruise control on.

ACLdestroyer

Hmmmm. Well the car had the problem when brand new so I doubt the TB is dirty. Will take to dealer and report back.

BuzzL

Is the problem like this?
http://www.youtube.com/watch?v=-xXsyVOAAx4

Do you guys have S-tronic gearbox in your car?
This problem has been reported in European forums for A4's with S-tronic (also other Audi models). There should be a S-tronic software update, which should eliminate this problem.

cparson

I have noticed something possibly related on my 6MT... under gentle acceleration at medium speeds, while the RPMs seem to climb consistently, the actual power seems to surge (more like drop, then come back, then drop, etc.) I wonder if that could correspond to the RPMs surging on an automatic - the auto trans adjusting RPMs to account for the brief drops in power?

It's about the same frequency as in that Q5 video, a drop & surge about every second. Do you know if the software fix was for the transmission itself?

I mentioned to the dealer about a month ago and they said it was something that Audi was aware of but didn't have a fix for yet.

matthewsjl

I've had a similiar surging on my 09 Prestige. It's more pronounced since chipping (Stasis) and is most likely to occur under mild accelleration when the rpms jump up to around the 3k mark.

John.

BuzzL

As far as I have understood, this phenomenon happens only with S-Tronic when driving at constant speed (with cruise on). So the software fix for S-Tronic transmission should correct this. The car which had the S-tronic SW fix was A4 B8, delivered May 2009. The software fix was possibly from Q5, although the car was A4 B8, but the car owner was not sure about it.
Probably the newest models already have the latest software in.