M3 Noises (What's Normal/Not Normal)

[JRMorgan]

I get the LSD cracking sound on low speed (parking lot speed) sharp turns. I heard it's normal so no worries.

[swagkingcole]

Originally Posted by saxodreng

could you maybe try to record it - sound file or a video ?

maybe we all are taking about the same noise, but having different experience with it.

I will try to make a recording of my experience with the noise I am talking about and then upload it here.

take care my fellow M-people.....

I'll try to get a recording as well

[saxodreng]

Originally Posted by banditM3

Sorry, I answered that after a long night. No, mine is definitely a rattle sound, not a grinding noise. I really think its shitty gas. I filled up today with BP and havent heard it since.

Which octane do you use in USA ? - we have in Denmark 92, 95, 99 octane.

all versions are mixed with 5% bio-ethanol, which is political decided years ago.

I have heard that US uses lover octane than the EU - correct ? and in my M3 manual they recommend at least 95 octane, but with Shell's VPower 99, it runs better.

[PeruM3]

I know the rear "clunk" sound is normal on 6MT cars when driving in 1st and pressing the clutch pedal.

What about the same sound on gear shifts (1st to 4th) at low rpms (below 4,000) and at 5,000rpm if I'm driving at WOT in 4th and quickly let off the gas? Is this normal too?

I can get used to this sound but I just keep thinking that something is going to break at some point. I thought it could be the differential bushings so I got solid ones. Same thing, maybe a little bit worse now plus differential noise which I can tolerate so far.

Bought my 2008 6MT with 22,000 miles on it a couple of months ago. Always had these sounds.

[Usp45nh]

Our 2008 E-92 has many of the listed noises and rattles. Makes me feel better, glad we got a normal one ��
For that matter all of our cars have some sort of noise, rattle and or squeak...

[Helmsman]

Here's an odd one guys: After driving the car warm coming back to the garage, maybe doing something for a minute or two before leaving, it goes "bang" from the front right side. First times I almost got spooked because it is a pretty significant bang.

After a while I got used to it and decided it's simply something bending back with the temperature coming down. It may be the fender but hard to say and not sure plastic would make that noise.

Strange one but doesn't worry me really. Someone else recognize this?

Cheers

[Leo985i]

I get this really annoying rattle coming from the driver's side seat belt housing; it is SUPER ANNOYING!!! Also, the passenger headrest likes to rattle a lot, and there another annoying rattle too coming from the rear seats some where. God knows where else all the other smaller noises are coming from, the car is pretty loud when going over shit roads and bumps. Dashboard started rattling a bit too sometimes. Oh and lets not forget about the stiff rubber door seals - when going over 75mph I can hear the outside wind sipping inside the cabin very loudly. When the car is on neutral and clutch engaged the transmission makes this horrible helicopter noise, and many other noises just cruising around specially when driving slow. Other than that, this car has never had any major issues. My car is an 08 MT with 51k miles btw.

[Flying Ace]

Originally Posted by saxodreng

Which octane do you use in USA ? - we have in Denmark 92, 95, 99 octane.

all versions are mixed with 5% bio-ethanol, which is political decided years ago.

I have heard that US uses lover octane than the EU - correct ? and in my M3 manual they recommend at least 95 octane, but with Shell's VPower 99, it runs better.

US octane ratings are going to APPEAR lower than the rating displayed in EU. Depending on the composition of the fuel, the MON of a modern pump gasoline will be about 8 to 12 octane lower than the RON, but there is no direct link between RON and MON. So you can't directly compare EU and US octane.

http://en.wikipedia.org/wiki/Octane_...rement_methods

EU: RON method of calculating octance

US: average of RON and MON

Regular gasoline has a RON rating of 91-92, but US AKI comes out to 87. It's still the same gasoline, just rating number is different based on calculation method.

[saxodreng]

I finally got a very good possible explanation of the "leaky noises" on my M3:

http://forums.m3cutters.co.uk/showthread.php?t=107453

http://www.bmwetk.info/parts-catalog...32/11727838028

I will have mine checked and those replaced if faulty and I will update here.

[JerezBlkM3]

I just installed the modded OEM exhaust (ACM style) and have noticed a sporadic metallic sound at times when I'm coming off throttle (usually after a spirited run up to 4k or higher rpms). It boggles my mind what it may be because it is random and I cannot always create the sound when trying to figure where it is coming. It sounds like a flattened aluminum can scrapping and bouncing along the pavement. It is a very brief and rapid metallic sound.

I installed the exhaust myself and it was pretty straightforward, but I'm wondering if the clamps may not be aligned properly. I know all the nuts and clamps were really tightened down good. I wonder if anything is clapping against a heat shield or something? Anybody else hearing pronounced metallic sounds coming from their car after installing their exhausts? Thanks!

[lve2xlr8]

Originally Posted by JerezBlkM3

I just installed the modded OEM exhaust (ACM style) and have noticed a sporadic metallic sound at times when I'm coming off throttle (usually after a spirited run up to 4k or higher rpms). It boggles my mind what it may be because it is random and I cannot always create the sound when trying to figure where it is coming. It sounds like a flattened aluminum can scrapping and bouncing along the pavement. It is a very brief and rapid metallic sound.

I installed the exhaust myself and it was pretty straightforward, but I'm wondering if the clamps may not be aligned properly. I know all the nuts and clamps were really tightened down good. I wonder if anything is clapping against a heat shield or something? Anybody else hearing pronounced metallic sounds coming from their car after installing their exhausts? Thanks!

My guess is it's hitting a heat shield. I'd go around the exhaust for clearance. It moves about an inch rearward at WOT.

[JerezBlkM3]

Originally Posted by lve2xlr8

My guess is it's hitting a heat shield. I'd go around the exhaust for clearance. It moves about an inch rearward at WOT.

Thanks for the tip! Sure enough I had one of the screws of the compression clamps right up against the heat shield. You could see the scraping it did to the heat shield after I moved it. The car is a lot quieter without that vibrating against the shield.

I still have the metallic sound at high revs and I isolated it to the intake area. I think someone posted about this before (throttle bodies?), so I'll check through the pages on this thread. It does not sound good at all, but does not seem to be affecting anything either.

[nthretourNAFTW]

I sometimes get a barely audible sound in the first 2 minutes of road drive, engine still warming up, if accelerating moderately in 3rd to get slightly above traffic speed on the first main road stretch . It's hard to describe with words, but it sounds like air suction in the induction or maybe like valves tapping. It is very very faint, and only happens when engine is not warm yet on that first moderate acceleration. Probably could not be heard if recorded with a cell phone.
Yeah i thought about RB, but don't think so. I think it could be the sound of air resonating the intake when one valve closes until the next one opens resonating at some RPM. I could be wrong as it only happens when engine not fully warm. Or some part of the valvetrain normal warming process. I am the factory owner of the car, still low mileage. probably had it from the beginning. Not really worried about it.

[JerezBlkM3]

Thanks for your feedback on this and it sounds like this may be "normal". It seems more pronounced I guess after doing the OEM exhaust mod. I took another spin after my last post mixing in some aggressive driving and mild cruising, but could not create the sound. I'm going to try not to worry as no fault codes are getting thrown and performance is as strong as ever with the engine.

[saxodreng]

Follow up...

It was the the emmision valve that leaked - sounded like broken manifold gasket.

http://bmwfans.info/parts-catalog/E9...ntrol_air_pump

(Nr. 5 & 6 - on the drawing)

Both valves was changed today - and boy - for the first time my M3 sounded like a proper V8 - awesome sound - and i'm soooooo happy.

A danish Mechanic confirms what Beemdog (in here) described. In some occasions, the valve does not close correctly and allow pressure from the manifold to go backward through the valve. This sounds exactly like and manofold leak / broken manifold gasket.

[FISH22]

Originally Posted by saxodreng

Follow up...

It was the the emmision valve that leaked - sounded like broken manifold gasket.

http://bmwfans.info/parts-catalog/E9...ntrol_air_pump

(Nr. 5 & 6 - on the drawing)

Both valves was changed today - and boy - for the first time my M3 sounded like a proper V8 - awesome sound - and i'm soooooo happy.

A danish Mechanic confirms what Beemdog (in here) described. In some occasions, the valve does not close correctly and allow pressure from the manifold to go backward through the valve. This sounds exactly like and manofold leak / broken manifold gasket.

Interesting. I have noticed on my '11 E90 M, that after the cat warm up cycle ends, if I continue to let the car sit and idle, the same raspy sound will come back... or, if I let the heat up cycle finish, then start driving or just tap the throttle, it will come back. Only lasts for a few seconds once moving, but I still always wondered about this... why the car sounds like it's entering a second warm up cycle.

[saxodreng]

Fish22:

Exactly - thats the Emission valves.

Change them and you will be stunned by the difference.

A further interesting thing is that my mechanic did some homework before he started the work, and found out that on a MT-transsmission, it was 50% quicker to remove the gearbox and access them from below, rather than follow the BMW work description and time estimates.
BMW estimates the work to last from 7-10 hours - mine (both valves, tubes and gaskets) was done in 5 hours (1 mechanic) including testdrive and lunch.

[PeruM3]

Rear differential clunk. Normal or excessive drivetrain lash?

I had it checked and its definitely coming from the differential. I understand the M3s have more than a standard "lash", but how much is normal?

Initially I thought it could be worn differential bushing so I switched to Tuner's solid delrin mounts. It just made the noise worse. Now I can hear a small clunk even if I'm cruising at 2,500rpm in 4th and let off the gas pedal. I get the noise on all gears when letting off the clutch (unless I do it EXTREMELY slowly).

These videos show the extreme scenario. Going very slow and letting the clutch go in 4th (it almost stalls the car). But the sound is pretty much the same when driving it normally. Its just easier to capture the sound with no road noise. I obviously don't drive like this normally.

BTW I feel no problem or hear anything odd when driving the car hard, even at the track.

[u2b]https://youtu.be/TSoVV6n5oow[/u2b]

[u2b]https://youtu.be/DhWtnUj-0HQ[/u2b]

[u2b]https://youtu.be/vIxfC-y1CWo[/u2b]

[jester17]

Originally Posted by highyo

I may have missed it here but the sound of the brakes shrinking and tink tink tinking after a nice drive is bloody fantastic. besides WOT in 2nd or 3rd gear, or the blip in downshift that may be my favorite M3 sound. all of which are perfectly normal. and awesome

and i have the drivers pillar noise which i know is not normal.

Ah... so THAT'S what that is! Thanks! Glad to know "it is what it is"!

[JHFW89225]

i've recently heard a faint whirring noise at idle and seems to go up along the rev, any ideas?

[PeruM3]

Potentially just low steering fluid. Fill it up and should be solved.

[xxxian08]

This is a great thread for a new E90 owner. Good to know all the noises I hear are normal (which I suspected).

It also reminds me of photography. I used to shoot with a Pentax LX which was incredibly noisy. I moved to a a Pentax DSLR which was pretty quiet and then switched to Canon. My 1DIV is f-ing LOUD!

It seems I'm most happy with loud mechanical things!