Unstable idle around 40km/h

[STomHacks]

Hi guys,

I have and Audi A4 Avant B7 2.0t and I have a problem mostly when the car is cold.
As you can see in the video below, when I'm with a stable speed like 40km/h the idle is'nt stable, it's a bit difficult to explain but you can understand if you watch the video.

Do you have an idea for this problem ?
I thought about pcv valve or spark plugs maybe no ?

[Der Konig]

First off, wrong discussion forum.

Second, are you sure its not RPM related and not kph? That would make a lot more sense. What trans?

[Atomic Avant]

Check your transmission fluid level.

I am guessing that this is an automatic? when the fluid level is low the car can "hunt" to maintain a constant speed. it could also be an indication of your torque converter on its way out, from my understanding it has an internal seal that starts to leak and it develops a hard time to lock into a constant speed. If you speed up or slow down at all the "hunting" goes away as you are in a constant change of speed.

I speak of course from some experience (mine does this and is worse when the level is low) as well there are some discussions that can be found on the topic.

Good luck I hope this helps.

I would also try posting this into the right sub-forum, this one is for B6/B7, S4/RS4 specifically. You might get more help in the regular B6/B7 sub-forum as most of the guys here like to 6 speed swap them before the even get home.

[Okedokey]

https://www.audizine.com/forum/showt...m-h-2-0T/page2