View Full Version : Rough Idle


Uol
05-15-2007, 03:29 PM
Hi everyone,

I've been experiencing an occasional rough idle in my 06 Z4 3.0si and I was wondering if this is unusual. It happens at random occasions, sometimes immediately after startup, sometimes after normal driving. The idle fluctuates between ~600 to 900rpm, and the tach needle appears to bounce around in that range. Also, when I turn off the engine, it shuts down very abruptly (more so than any other car I've ever owned) and there's a very subtle clatter. I'm sure the rough idle is a problem, and I'm a little suspicious of the shutdown. The car has only 1800 miles on it, and it has been doing this sporatically pretty much since I picked it up.

I've done some research on this, and I've found that some 330s and 530s with the N52 have experience problems with the valvetronic and bad lifters. I don't think I have bad lifters because I have no ticking during normal operation (or anytime actually), but I think this might be a valvetronic issue. Unfortunatley, I've read that some dealers dismiss the rough idle as "normal," and I wouldn't be surprised if they said the same of the shutdown noises. I'm going to call my dealer (Morristown BMW) sometime this week, but I would like to be fully prepared to challenge them should they claim this is normal. Does anyone know what this problem could be or of any service bulletins I can reference? What is shutdown like in your car, providing you have an N52?

Many thanks,
Lou

2002Z3
05-15-2007, 03:59 PM
#1 You'll get more responses on the Z4 threads - oh wait, you did... sorry.
#2 Why haven't you taken it to the dealer - it's under warranty right? :confused

Best of luck.

Tony P
05-16-2007, 01:07 PM
I have the rough idle at start up, but it goes away soon after I put it in drive and go. I'm not too concerned. I only have 2,200 miles; but I've experienced no real problems.

335i Piotr
05-16-2007, 04:16 PM
Same thing here...rough idle at startup, but then goes away as you drive. My previous BMW had the same thing. BMWs are know for rough idle at startup (at least the ones I came across had rough idle)...

azukko
05-16-2007, 04:50 PM
clean the icv. i had this problem less than a week ago - rough idle only at start-up, it would go away in 5 or 10 seconds and wouldnt return again the whole drive. the thing was filthy dirty! took it out, cleaned it with carb cleaner, wd-40, put it back in and it doesn't idle anymore.

335i Piotr
05-18-2007, 10:31 PM
What does ICV break down to?

Austxe90
05-25-2007, 10:25 AM
clean the icv. i had this problem less than a week ago - rough idle only at start-up, it would go away in 5 or 10 seconds and wouldnt return again the whole drive. the thing was filthy dirty! took it out, cleaned it with carb cleaner, wd-40, put it back in and it doesn't idle anymore.

It's a new f##k'n car...I have had to take mine to the dealer twice and it still does it.