Author Topic: Metallic Buzzing from Driver Kick Panel Area at ~3600RPM (Read 4328 times)

bmwman91 · « **on:** July 20, 2010, 12:28:14 PM »

Has anyone else run into this annoyance? There is a metallic buzzing noise that comes from (well, seems to come from) down in the kick panel on the driver's side. It is worst at ~3600RPM, but will make noise anywhere between 3500 & 4000RPM. The only thing I can think of that it would be is the impact switch in the central locking module (the little steel ball might be moving around inside of it). It drives me NUTS because that is the 70-80mph range in 5th gear!

Thanks for any help!

dvmotorsports · « **Reply #1 on:** July 20, 2010, 12:30:42 PM »

Check your speaker since that would be the easy way to start

bmwman91 · « **Reply #2 on:** July 24, 2010, 04:31:21 PM »

I know for a fact that isn't the speaker. It made the noise before my audio overhaul, and still does with the new gear in there (and the new speakers use cast aluminum frames).

fiftytakedowns · « **Reply #3 on:** September 19, 2010, 04:59:02 PM »

bump, relevant to my interests

bmwman91 · « **Reply #4 on:** October 04, 2010, 11:54:18 AM »

Well, it wasn't the metal ball in the impact sensor. Removing that made no difference. I guess I need to find a big empty parking lot where I can rev the motor to 3500-4000 RPM for a few minutes while I crawl around under the dash! Grrrr!

Good thing I finished my audio build...at least I can turn that up enough to drown out the buzzing.

enildeR · « **Reply #5 on:** October 04, 2010, 04:21:08 PM »

post what you find. I'm having a similar problem. it used to be my exhaust, but I had that fixed, and now it's come back, and I don't see any cracks in the exhaust. I can hear a slight metal rattling when I'm at idle just after starting the engine. I haven't gotten around to seeing if it's some metal in the cab under the dash that's doing it.

gearheadE30 · « **Reply #6 on:** October 14, 2010, 02:05:05 PM »

I kid you not, mine was the headlight switch. The shaft was rattling just a little bit; just enough to be annoying.

L0c4lh0sT · « **Reply #7 on:** July 27, 2011, 03:37:33 AM »

I have the same problem. Between 3000 rpm and 3800 rpm i hear a buzzing noise. Sounds like a piece of meat in a pan full of hot oil sometimes.

Im sure it is not the headlight switch because it only appears when the engine is warm. If the car is cold, i can't hear anything.

DesktopDave · « **Reply #8 on:** July 27, 2011, 04:43:35 PM »

Mine has loose converter heat shields that buzz until the exhaust pipe warms up.

bmwman91 · « **Reply #9 on:** July 27, 2011, 07:30:59 PM »

Well, I figured out what the interior noise was. It is the clutch master cylinder. The linkage is tight, but it seems that some rubber bit inside is worn & the input shaft thing can move around a bit & make noise. I have a rebuild kit for it (had it for a year) that I need to get around to.

I also noticed that I get a lot of rattle from the timing chain between 3000RPM & 3500RPM. it only does it when the motor is warmed up. The tensioner piston has ~20k miles on it, so I wouldn't think that it is from that. I recently fixed a stripped bolt on the driver's side guide rail that eliminated a bad bad noise, and this must have been masked by that. I swear this rattling is a new occurrence ever since I rebuilt the timing case, but i cannot be sure. The worn idler sprocket might have been masking this all along. What might it be? I double checked all of the bolts when I reassembled. Could it be that the M42 timing chain is just plain noisy?

91 e30m42 · « **Reply #10 on:** October 10, 2011, 05:22:21 PM »

great

Choking Hazard · « **Reply #11 on:** November 16, 2011, 02:59:29 PM »

when mine went al noisy, it turned out the t-chain rail had disentigrated.

bmwman91 · « **Reply #12 on:** December 01, 2011, 03:00:50 AM »

Quote from: Choking Hazard;108095

when mine went al noisy, it turned out the t-chain rail had disentigrated.

Oh, there's a little bit of that going on, too. That is a DIFFERENT rattle, though. I will be pulling the timing case covers off one of these upcoming weekends & replacing the large driver's side guide rail. The *****ded brass piece at the top seems to be a little loose in the surrounding plastic, and once the car warms up & things expand, it makes heinous noise around 3100RPM.

I still need to fix the rattling clutch master cylinder since that was what was originally irritating me. This means pulling the carpet so I don't get fluid on it, and then dealing with the fluid. Yuck.