Annoying whine at 3200 rpm

[jpherit]

My 2001 325i (five speed manual) has had, from the get-go, a whine that appears at about 3000 rpm and persists up to about 3500 rpm. It occurs with the engine under load, light or heavy, and goes away when I back off on the throttle. It is most evident on the highway in fifth gear and as such makes long drives of over an hour or so a little tiring. Interestingly it disappears below 3000 rpm. This means I can cruze at 60 mph with out the anoying whine or above 90 mph :angel:. I would prefer to cruze some where between those speeds but the noise gets to me after an hour or so! :mad:

It sounds to me like either an induction or exhaust resonance or perhaps differential whine, but why would that ocur only at certain speeds?

Does anyone else have this problem and if so have you been able to track it down and get it corrected? :dunno:

[Alex Baumann]

Hello,

take a look at the threads below. :)

http://www.bimmerfest.com/forums/showthread.php?t=2759

http://www.bimmerfest.com/forums/showthread.php?t=14622

Take care

Alex

[bmw325]

jpherit--

Check the the threads that Alex listed. It sounds a lot like my differnential whine problem that I had from new w/ my 2001 325i 5 speed. It was solved by applying a butyl strip piece of insulation to the center bearing (there is absolutely no whine now)-- check out the threads.

[jpherit]

My 2001 325i (five speed manual) has had, from the get-go, a whine that appears at about 3000 rpm and persists up to about 3500 rpm. It occurs with the engine under load, light or heavy, and goes away when I back off on the throttle. It is most evident on the highway in fifth gear and as such makes long drives of over an hour or so a little tiring. Interestingly it disappears below 3000 rpm. This means I can cruze at 60 mph with out the anoying whine or above 90 mph :angel:. I would prefer to cruze some where between those speeds but the noise gets to me after an hour or so! :mad:

It sounds to me like either an induction or exhaust resonance or perhaps differential whine, but why would that ocur only at certain speeds?

Does anyone else have this problem and if so have you been able to track it down and get it corrected? :dunno:

Thanks to Alex and robg for the leads. I'll look into it and let you know the results.

JPHerit

[bmw325]

Thanks to Alex and robg for the leads. I'll look into it and let you know the results.

JPHerit

Cool. Let us know how it turns out. One thing to be aware of--the dealer may tell you that the TSB only applies to cars w/ auto transmissoin (that's what my dealer told me at first), but I persisted, and it did solve the problem. The service guy actually wanted to replace my whole differential-- and told me it might not even solve the problem bceause he'd replaced a bunch of diffs in M5s and they still whined. So, its some sort of design problem that can only be truly fixed by applying the insulation. I pointed out that would be cheaper/easier to atleast try the butyl strip, and sure enough, it worked like a charm. Supposedly this insulation was introduced into production sometime late in the 2001 MY-- but my car clearly didn't come w/ it- and yours probably doesn't have it either. I also was convinced that it was some sort of intake noise for a while, btw. I noticed that it seemed to emmenate from the front passenger foot well (clearly this is not really the sourc eof the noise, but that's where it seemed to be loudest in my car).

[jpherit]

My 2001 325i (five speed manual) has had, from the get-go, a whine that appears at about 3000 rpm and persists up to about 3500 rpm. It occurs with the engine under load, light or heavy, and goes away when I back off on the throttle. It is most evident on the highway in fifth gear and as such makes long drives of over an hour or so a little tiring. Interestingly it disappears below 3000 rpm. This means I can cruze at 60 mph with out the anoying whine or above 90 mph :angel:. I would prefer to cruze some where between those speeds but the noise gets to me after an hour or so! :mad:

It sounds to me like either an induction or exhaust resonance or perhaps differential whine, but why would that ocur only at certain speeds?

Does anyone else have this problem and if so have you been able to track it down and get it corrected? :dunno:

I have been very busy since I posted this concern and have thus been unable to find the time to go get this problem corrected by BMW as several of you have suggested. However, the whine, in the meantime has reduced in volume to the point that I have to really concentrate to hear it. :)

I believe that the improvement I have experienced over the last four months is a result of simply breaking in the gears/differential. When I reported this noise my 325i had only about 7500 miles on the odometer. However, in the last ~ 2 months I have put on about 8,000 more, mostly highway, miles as a result of business needs. These miles seem to have significantly reduced the noise. I am happy! Anyone else have a similar experience?

[PhilH]

I have a bit of the whine, but I know what it is (thanks to these threads), and I don't worry about it. It sounds like this is more an "auditory" problem than a mechanical problem that could lead to a repair.

I've just chalked it up to those crazy Germans who consistently drive 90 mph or more, so they didn't even test the car at extended periods at 75 mph. These types of "problems" are sort of typical of BMW. I don't think the Germans care as much about mechanical noise as Americans, as long as the car does its job.

Plus, I'd rather have a slightly noisy car that works, than one that has real problems because it was taken apart by a dealership and put back together wrong.