Idle revs jumping up and down at some point after a cold start on my 2000 528i

[glazy]

Hello,

Can smb. give me a valuable piece of advice?
I've noticed the problem when it was very cold here in PA.

The car has NO problems starting (cold or warm engine), and NO problems
with idle when the engine has warmed up.

BUT when I start the engine, drive for several hundred feet and then have to stop
at the nearby traffic light for a long enough time (the temp. needle slowly going from the "blue" zone to normal), the revs suddenly start jumping high and low!
Once the engine has even stalled after the RPMs dived below 200 or so.
(I didn't have problems re-starting it.)

The same thing occurs when you start a cold engine (left for at least 6-8 hours)
and leave it warming up in idle mode for several minutes.

- I haven't heard any suspicious noises, and haven't noticed any other problems.
- It doesn't happen when the engine is warm enough right from the start.
- It doesn't happen when the engine is COLD - only during a short period
when it goes from cold to normal.
- The car has got a stick and approx. 50K miles, spark plugs are fine.

Thanks a lot in advance!

 

[epj3]

Almost positive it's your idle control valve. My car does it too -- yes it's older but I believe they use the same kind of valve system for idle. It could be that, or the injectors or something on the fuel system could be messed up.

If you can, take the idle control valve out and clean it well with some carb cleaner. Mine will just need to be replaced, but your car is new enough that it SHOULD be okay.

 

[glazy]

Thanks a lot - I concur...

Thank you so much - I also tend to think along these lines. I will try it next week...
The injector has bee cleaned recently, so there are no suspicions in this area...

 

[BMW NA Customer Relations]

I’m with BMW of North America, LLC. I’m sorry to read about this problem with your 538i. If you and your BMW center would like our assistance, please phone us at (800) 831-1117, and mention Reference #200403702804 so that we can help you more efficiently.

BMW NA Customer Relations and Services

 

[donmbmw]

Are you for real?

I’m with BMW of North America, LLC. I’m sorry to read about this problem with your 538i. If you and your BMW center would like our assistance, please phone us at (800) 831-1117, and mention Reference #200403702804 so that we can help you more efficiently.

BMW NA Customer Relations and Services

If your really with BMW NA and you want to some good, then go to the E46 forum and check out the "Sliptronic" thread. It's easy to find considering it holds the record on this board for views and reply's. Anyway, I brought my '04 330i to the dealership for tranny slippage on 12/29/03 and was told that BMW NA (i.e. YOU) are aware of the problem and were going to ship a "repair kit" to the dealership and they would call me when it came in. Guess what? I'm still waiting.

 

[Dinan55]

How cold?

 

[glazy]

Probably, amboient temperature doesn't matter

Hello,

I guess it was smth. like -15C (5F). But it doesn't seem to be the cause - this thing happens NOT when you start the engine, but when it's already hapf-warmed up. It happened today (~28F) in exactly the same way. I just noticed it first time when it was cold - probably, a coincidence. I will have the valve cleaned next week and will post the results...

 

[glazy]

Regrettably, it didn't work...

Here I am again with the sad news: a good guy at a local shop has cleaned the idle control valve thoroughly (he also balmed it for this trouble), as well as the fuel supply, and it didn't help at all... He also said that, if this doesn't help, it could be one of the temp. sensors failing without an error code. What do you think? Could it be the case?

 

[speedjunkies750]

Hey Glazy,
Sorry to here about your troubles. I have the same trouble. Any temp under 37~f it runs rough at start. I have an appointment the end of the month with BMW. If I get results I will let everyone know. Good Luck!

 

[528iheat]

Yeah let us know i have the samething. 99 528i

 

[wileymo]

It could possibly be a problem with your VANOS. We have done many of them that cause a idle surge when cold. You can verify the problem by disconnecting one of the VANOS solenoids (the exhaust on is easier to get too) while the idle is surging. If it evens out the VANOS is faulty.