E90 6MT Engine or trans resonance/gurgle (driving me nuts)

[bkrM3]

Hey dudes (and dudettes?) my car is making a noise that's really bugging me.

The car: 09 E90 6MT, everything stock except AA green filter. Sound was also there with OEM filter, so that's not the issue.

Oil service done a few weeks ago, along with diff fluid flush. Made no difference.

On hard acceleration it's perfectly fine. On straight deceleration it also seems to be fine. If, however, I get in the range of 4-5,000rpm and then maintain throttle there I get a weird gurgle noise. At first I thought it was intake/engine related but I guess I can't rule out something transmission related either. Seems to do it in every gear EXCEPT 6th, although I haven't spent much time at 5,000rpm in 6th bc that's, umm, very illegal.

It doesn't seem to make this sound if revved and held in the same range in neutral.

No unusual noises at all from the engine at idle.

No unusual noises from anything clutch related, whether open or not (i.e., no throw out bearing noises or anything of that sort).

Also - car is out of warranty (time, not miles).

I'd love to figure out if this is cause for concern because the car is going to have 2 days on the track at new jersey motorsports park at the end of next month in the (probably) awful August heat.

Here's a video - sound is best heard from 0:11 - 0:40ish, end of the video is in 3rd gear at lower RPM for comparison. You'll need decent speakers or headphones. Any thoughts are much appreciated.

[thekurgan]

I hear the sound as you back off the throttle. When you mean oil service, you're speaking of the engine and not the transmission? It does sound transmission/clutch related. If it were the guibo, you'd hear weirdness and feel vibrations upon acceleration.

[bkrM3]

Originally Posted by thekurgan

I hear the sound as you back off the throttle. When you mean oil service, you're speaking of the engine and not the transmission? It does sound transmission/clutch related. If it were the guibo, you'd hear weirdness and feel vibrations upon acceleration.

Yes, engine oil. 6MT fluid has not yet been changed. That's the next service...

Originally Posted by Purple Derple

My car does this. Personally, I don't think anything is wrong or: How I learned to stop worrying and love the noises.

I'll be thrilled if everyone says this. I know these cars make a LOT of noises - I just want to make sure this particular noise is not an expensive one.

I searched endlessly and could only find people complaining about noise in connection with clutching in/out. Come on people, flywheel and lash. Let's move on to the truly exotic noises ... like this one.

[Transfer]

When did you first notice it? Any other changes in engine or transmission behavior?

[bkrM3]

Originally Posted by Transfer

When did you first notice it? Any other changes in engine or transmission behavior?

Has been that way since I bought the car (in March). No changes in engine or transmission behavior at all. No difference in cold weather or 100 degrees. No difference with a warm or cold engine.

Everything seems fine (except the noise).

[Edjay]

A long shot since it seems like your going straight on the video. But it sounds like you need a diff service. I had that exact sound, but mine was when turning and a diff service got rid of the sound. Maybe do the transmission and diff service.

[SenorFunkyPants]

Hmm tough noise to diagnose...I don't think its the diff...my guess would be the dual mass clutch loading and unloading...except that if it doesn't do it in 6th then that points to the MT itself.

[radiantm3]

Normal. Mine has done that since I got the car.

[bkrM3]

Originally Posted by radiantm3

Normal. Mine has done that since I got the car.

You're the second one so far. I'm feeling better about this already!

[s65e90]

read the manual it explains it all

[bkrM3]

Originally Posted by s65e90

read the manual it explains it all

I have read every page of it, and most pages more than once.

It does not, in fact, explain the noise I've described, although it does give an example of a resonance at 2,000rpm in 5th gear, which is clearly not the noise in question.

Thanks for your contribution.

[s65e90]

Originally Posted by bkrM3

I have read every page of it, and most pages more than once.

It does not, in fact, explain the noise I've described, although it does give an example of a resonance at 2,000rpm in 5th gear, which is clearly not the noise in question.

Thanks for your contribution.

below is a picture of the manual where it states that you will hear driveline lash and other clunks in this car. M3 tend to make alot more noise than a regular BMW; it's inherent in the performance design. Your welcome for my contribution

[bkrM3]

^^ Allow me to repeat myself: I've read the manual.

Is it "acoustic feedback?" What does that even mean? That's so vague as to be entirely unhelpful. In my experience, one must listen to a car and use one's brain if necessary.

Is it "clacking during load changes?" I wouldn't call the application of throttle to maintain 4,000ish RPMs a scenario in which "load changes" should precipitate "clacking," and even then I wouldn't call it "clacking," although who knows what sort of German choose that specific word for the translation. The manual's description almost certainly applies to the actual clacking made by the drive train at parking-lot speeds, of which there is plenty.

I drove a friend's E92 DCT and it didn't make the noise now at issue.

Two people in this thread have said that their cars do make the same noise.

I appreciate your implication that is a no-brainer issue, and I disagree. If I thought I should ignore the noise based on what the manual said, this thread wouldn't be here.

So, does YOUR car make this noise or not?

[s65e90]

Originally Posted by bkrM3

^^ Allow me to repeat myself: I've read the manual.

Is it "acoustic feedback?" What does that even mean? That's so vague as to be entirely unhelpful. In my experience, one must listen to a car and use one's brain if necessary.

Is it "clacking during load changes?" I wouldn't call the application of throttle to maintain 4,000ish RPMs a scenario in which "load changes" should precipitate "clacking," and even then I wouldn't call it "clacking," although who knows what sort of German choose that specific word for the translation. The manual's description almost certainly applies to the actual clacking made by the drive train at parking-lot speeds, of which there is plenty.

I drove a friend's E92 DCT and it didn't make the noise now at issue.

Two people in this thread have said that their cars do make the same noise.

I appreciate your implication that is a no-brainer issue, and I disagree. If I thought I should ignore the noise based on what the manual said, this thread wouldn't be here.

So, does YOUR car make this noise or not?

yes all of my M3s have made some sort of driveline noise and it's totally normal. All m3s sound like sewing machines that clunk, whir and buzz. It is what it is.

edit: what you're hearing is harmonics related to the driveline lash (as stated in manual as well) clacking and clunking is more low speed/gear changes or modulating the gas due to the driveline lash but what you're hearing is 100% normal


***the only other issue I would check would be wheel bearings as at speed they can hum and I do see them make noise on some cars and need replacement sooner than expected, but based on your first post it seems to corelate to driveline noise***

[bkrM3]

Originally Posted by s65e90

yes all of my M3s have made some sort of driveline noise and it's totally normal. All m3s sound like sewing machines that clunk, whir and buzz. It is what it is.

edit: what you're hearing is harmonics related to the driveline lash (as stated in manual as well)

Thanks, without a basis for comparison (I only own 1 M3 after all) it's hard to know what's really "normal" for these things.

I think that what I probably need is a louder exhaust. Been eyeballing the Gintani myself.

[s65e90]

Originally Posted by bkrM3

Thanks, without a basis for comparison (I only own 1 M3 after all) it's hard to know what's really "normal" for these things.

I think that what I probably need is a louder exhaust. Been eyeballing the Gintani myself.

loud mufflers def help as now I don't hear anything. When the car is quiet you think every noise is something about to go bad and cost $$$ lol

[spyderco10]

I'm pretty sure my car makes this same noise while cruising around 4-5000 rpm, noticeable mostly in 2nd gear. At first I thought something was wrong with my car too. Mine's a 2008, about 20k miles, heard the noise since day 1.

On another note, I also have the low speed turning, grinding noise from the differential. This one started at 20k miles. I had the differential fluid changed to the one with the slip agent and the noise seems to have gotten worse.

[FormulaMMM]

Normal. Can also be heard at lower speeds in higher gears, in my experience. e.g. 5th gear ~40 mph, off throttle.

[jrlee53]

I hear the same thing, just thought this was normal, doesn't seem to hamper anything

[Tora]

I also have this exact same gurgle. Took it to the dealer and the lead tech and I went in another E92 M3 and heard the same noise, so they wrote it off as normal. Regardless, it bugs the crap outta me and sounds like if something is loose in the engine bay.

Another noise I have is cruising in 6th at around 75-80: a kind of "braaar-braaar-braaar". A friend said it might be the tires (I have Pilot Sports 1 - CPO'd tire of choice I guess) or wheel bearings. Any thoughts on this?

[OC3]

Originally Posted by Tora

I also have this exact same gurgle. Took it to the dealer and the lead tech and I went in another E92 M3 and heard the same noise, so they wrote it off as normal. Regardless, it bugs the crap outta me and sounds like if something is loose in the engine bay.

Another noise I have is cruising in 6th at around 75-80: a kind of "braaar-braaar-braaar". A friend said it might be the tires (I have Pilot Sports 1 - CPO'd tire of choice I guess) or wheel bearings. Any thoughts on this?

(sorry, that just cracked me up)

[aussiem3]

What can cause the wheel-bearing to fail?