What is this sound?

[yahtzee]

If i am coming up to a stoplight and I have down shifted into 2nd gear I get a rattle when I push in the clutch...Sounds like a disengagement of some sort (assuming the clutch) but wasn't sure if that sound was normal.

[AJBoston]

I just noticed this last night too, but only in first gear. Sounds clutch-related, since it's exactly at the moment that it disengages the flywheel. Anyone else?

[!Xoible]

flywheel sound?

[ArtPE]

it's a dual mass flywheel, iirc, same as the e46, so it's a little rattle or vibration, the unit has 2 pieces that move a bit...

also appears to be a dual disc clutch, and the disc and flywheel are a sealed unit and must be replaced as a set...

[JAJ]

Originally Posted by yahtzee

If i am coming up to a stoplight and I have down shifted into 2nd gear I get a rattle when I push in the clutch...Sounds like a disengagement of some sort (assuming the clutch) but wasn't sure if that sound was normal.

It's just a little noise from the gears and bearings in the transmission, and possibly the flywheel-clutch assembly.

The M3 has less sound deadening than the regular cars so you hear more noises than with the regular cars even when everything is "normal". Also, this transmission is built to run hot - it even has an oil pump and cooler - and that dictates bigger running clearances when it's cold. "Cold" is a relative term - it's only "hot" when you've been running full throttle for a long stretch, like 5 or more laps at a long, fast track. Most daily driving, regardless of how aggressive you are, is not going to heat this gearbox up very much. Hence it will be noisy. It's just part of the mystique of having a fast car.

[gbelton]

Love that sound. Have it in my SMG too; clunk, clunk...

Keeps you focused on the being alive!

[drvai]

Those sounds are one of the reason I went for a MT.

[yahtzee]

Originally Posted by drvai

Those sounds are one of the reason I went for a MT.

We cant be talking about the same sounds if this is the case. It sounds as if it shouldn't be happening....I am not talking about anything internal to the transmission. It sounds a little like a plastic piece having some pressure taken off of it.

[drvai]

Originally Posted by yahtzee

We cant be talking about the same sounds if this is the case. It sounds as if it shouldn't be happening....I am not talking about anything internal to the transmission. It sounds a little like a plastic piece having some pressure taken off of it.

mmmm. I see.

I guess that your best bet would be to take it to the dealer.

[Hans Delbruck]

Sounds like the "clunk" -- a standard feature on BMWs and nothing to worry about. Happens when you push in the clutch at low speeds, like a little knock knock.

[yahtzee]

Originally Posted by Hans Delbruck

Sounds like the "clunk" -- a standard feature on BMWs and nothing to worry about. Happens when you push in the clutch at low speeds, like a little knock knock.

That's it....it's normal?

[southlight]

Originally Posted by yahtzee

That's it....it's normal?

Yes, that load change clunk is normal.


Best regards, south

[kevinz]

Odd... I was going to ask the same question. Guess it's normal =S

[yahtzee]

Originally Posted by southlight

Yes, that load change clunk is normal.


Best regards, south

Why is it that this is the only MT that I have ever heard do this?

[SS32]

My E46 was the only one I had heard it on, until I got the M3. It's normal; don't worry about it.

[Hans Delbruck]

My 2006 Z4 M Coupe did it too..... until I sold it. Then I didn't hear it anymore....

[southlight]

Originally Posted by yahtzee

Why is it that this is the only MT that I have ever heard do this?

It's not normal for all cars, but on an M car, yes it is.


Best regards, south

[GregW / Oregon]

Originally Posted by yahtzee

Why is it that this is the only MT that I have ever heard do this?

If it's what people are assuming (hard to tell describing sounds with words), it's related to driveline lash in the MLock diff. E46 had it as well, as others said. You can learn to control it by the way you put in the clutch--don't do it to quickly when under negative load.

[yahtzee]

Originally Posted by GregW / Oregon

If it's what people are assuming (hard to tell describing sounds with words), it's related to driveline lash in the MLock diff. E46 had it as well, as others said. You can learn to control it by the way you put in the clutch--don't do it to quickly when under negative load.

Good to know...I'll work on that.....I cant believe the noise it makes, though.

[jm1234]

Wow, I just noticed this last night and here this morning I find a thread telling me it's normal. It's like this board is reading my mind!

Thanks!

[lucid]

Welcome to the world of the BMW MT clunk guys! I even took my E46 to the dealer when it only had 100 miles thinking there is something wrong with the transmission, and they just laughed and told me it was normal.

[lucid]

Originally Posted by ArtPE

it's a dual mass flywheel, iirc, same as the e46, so it's a little rattle or vibration, the unit has 2 pieces that move a bit...

Did the non-M E46s have dual mass flywheels as well?