Z4 rev gauge unstable when cold

[Erenbl]

Hey guys i recently got a 2003 z4, the car is on 74500 kms.Previous owner was not driving the car much often and the car was sitting in garage, rarely driven on the weekends.I haven't even drove the car over 150 kms and something happened, it bugs me. When i start the car rev gauge starts moving unstable.And this only happens when the car is cold.When car gets warm enough it stops. Can anyone tell me why this happens? Thanks.

Here is the video of it: https://www.youtube.com/watch?v=drX14UEBXA8

 

[GingerNinja]

Not sure if that's a problem or not? :|
My 2007 3.0si does exactly the same thing.
It bugs me too and I've been wondering if it's a sign of a vanos that needs replacing, but other than this mine drives just fine. :driving:

Anyone??

 

[Erenbl]

My car is driving fine too, i am just curious that it might be a problem.

 

[Steve84N]

Might be the idle control valve needs a clean.

 

[Jez_m]

Getting this occasionally too when cold. Thought it could be an air leak, but then it would be consistant whether engine was cold or hot. Thinking either the idle control valve, as Steve84N mentioned, worn spark plugs or possibly early signs of a coilpack on it's way out.

 

[stevo///m3]

Not sure if that's a problem or not? :|
My 2007 3.0si does exactly the same thing.
It bugs me too and I've been wondering if it's a sign of a vanos that needs replacing, but other than this mine drives just fine. :driving:

Anyone??

This will not be the VANOS unit. In the extremely unlikely event that it is, you won't need a new one, it can be fixed for relatively little, it just takes someone who is confident enough and preferably has a little experience.
Stevo

 

[GingerNinja]

Not sure if that's a problem or not? :|
My 2007 3.0si does exactly the same thing.
It bugs me too and I've been wondering if it's a sign of a vanos that needs replacing, but other than this mine drives just fine. :driving:

Anyone??

This will not be the VANOS unit. In the extremely unlikely event that it is, you won't need a new one, it can be fixed for relatively little, it just takes someone who is confident enough and preferably has a little experience.
Stevo

Thanks Stevo,
That's nice to know

So how do you clean a idle control valve??

 

[stevo///m3]

Don't know the answer to that sadly but I'm sure if you search you will find...or maybe someone more helpful will come along shortly...
Stevo

 

[Scooba_Steve]

I had a similar bit of fluctuation from cold start with no eml. Few months later intermittent eml from pre cat lambda. Worth reading codes just to see if there is anything there that has been recorded but not bounced the eml yet.