Driveline rumble, fluctuating revs at low rpm

Hey guys, this is my first post.. However I'm not new to e46 fanatics as I have spent some time trying to find the solution to this problem no mechanic (including BMW) can work out.. So here is my problem..

I'm experiencing a vibration/rumble down my driveline..
Apparently the guibo, diff, and transmission including gearbox are all fine according toy mechanic..
On an even throttle around 1400 rpm it seems my revs are fluctuating.. In other words, the revs jump up and down..


So far I've been told its not bearings, not guibo, not gearbox, not the maf..

The symptoms I'm experiencing may not be related, but I thought I'd include them in the same post..

C'mon guys, I need answers!

first thing, check your disa valve. You can do this yourself, take it out and see if the mechanism is broken (it shouldn't be able to flap around). If this is fine, you may need a re-coding. I had this same exact issue and a combination of the two fixed the issue completely.

Disa Valve is #7 below.
http://realoem.com/bmw/showparts.do?...79&hg=11&fg=40

Chek out these great DIY videos from solidjake





if the problem persists with the jumping rev and stalls, you have to fix your vanos seals
go to beisansystems.com for more info on that

Originally Posted by nickchuck

first thing, check your disa valve. You can do this yourself, take it out and see if the mechanism is broken (it shouldn't be able to flap around). If this is fine, you may need a re-coding. I had this same exact issue and a combination of the two fixed the issue completely.

Disa Valve is #7 below.
http://realoem.com/bmw/showparts.do?...79&hg=11&fg=40

I thought the disa would affect the idle as well?
For the record, I have no problems at idle, just in high gears at low rpm..

Did you ever solve this problem? I have the symptoms. When running at a constant speed (low rpm <2000) the rev jumps up and down. I think the rumbling you hear is a result of the uneven rev.