E39 Cold Idle Problem, Solution

[TWKTCC]

I have a 2000 528i. On cold mornings when I start the vehicle to warm it, it will idle fine then all the sudden almost stall then catch and idle fine. It will do this about once every minute or so for a few minutes then it behaves normal with a smooth idle. I recall someone else posting about this with little help for them as well as others saying "mine does it too it must be normal".

I just brought mine in for its "service 2" yesterday and mentioned it to them as an issue to look into. It turns out that my VANOS unit needs replacing. It isnt adjusting the timing accordingly as it should on those cold mornings. There is absolutely no drivability issues or service lights on in the car at all, just the strange idle when warming up.

Thankfully it is a CPO vehicle so the approximately $1000.00 repair will only cost me $50.00 and I get a new loaner for two days.

Just thought Id share this info. I hope it may help someone.

[LOS]

Let me just say thank you for posting this valuable information (PROBLEM, SOLUTION, COST).

LOS

[billB]

good write up

[SPR1]

Hello All,
New member here.
10 minutes in and I've already found the answer to my question.

Thanks TWKTCC!

Assume the $1000.00 was a dealer price.

Does anyone have more details on what the VANOS unit cost.
Can an experienced mechanic, or myself whos turned a few wrenches do it?

[Papa_Bimmer]

Wow! That's EXACTLY what my 2000 528i did today at 35 degrees. Idle, then almost stall. Accept this was every ten seconds. Thankfully I just bought mine three weeks ago as a CPO. But since it was only three weeks ago, I may be able to get away with it for free because I mentioned it when I test drove it before I bought it. I'm going to print this topic and take it to the dealer when I take it in. I get a free loaner as well. Whew!

[TWKTCC]

Originally posted by SPR1@Mar 27 2005, 11:24 PM
Hello All,
New member here.
10 minutes in and I've already found the answer to my question.

Thanks TWKTCC!

Assume the $1000.00 was a dealer price.

Does anyone have more details on what the VANOS unit cost.
Can an experienced mechanic, or myself whos turned a few wrenches do it?

[snapback]319841[/snapback]

All totaled it cost almost $1300.00, they had to replace some crankcase moisture seperator as well. It cost me $50.00 out of pocket, under CPO. I think the VANOS unit itself is around $300-400 and from what Ive seen online I wouldnt want to install it. Although, I probably would have dug in if it wasnt under warranty.
If I could remove, totally disassemble, send out for machining, reassemble, reinstall and drive the hell out of a small block chevy in an car I used to have, I guess I could have done this.... I hate wrenching at this point but if the savings are great Ill do it.

[mrogers]

My car does something similar when it's very cold (below 20F), but since it's a 1997 I don't think it has the VANOS stuff (I'm a little weak in my knowledge of engine differences). Is it VANOS that was added in 1999 or is that something else I'm thinking of? If that is it, then what do you suppose could be causing the same behavior on my car?