[Glene]

My 2011 335Xi developing a rumbling noise and I can't figure it out where it comes from. It makes noise in park, neutral and very pronounce in drive except in reverse. . Any suggestions where to look at?
Thanks,

[mousefarmer]

video please

[E92William]

Any mods done to it? Downpipes? I recently put headers on my 328 and one of the bolts had come loose and was causing a rattle sound for a bit.

[Glene]

Originally Posted by mousefarmer

video please

I posted the video.

[Glene]

Originally Posted by E92William

Any mods done to it? Downpipes? I recently put headers on my 328 and one of the bolts had come loose and was causing a rattle sound for a bit.

100% stock.

[mousefarmer]

Jack it up and get underneath it. I would do all the obvious things like drop transmission pan and change the fluid, look for loose screws underneath on panels, etc. There is also transfer case fluid to change.

[Glene]

Originally Posted by mousefarmer

Jack it up and get underneath it. I would do all the obvious things like drop transmission pan and change the fluid, look for loose screws underneath on panels, etc. There is also transfer case fluid to change.

.

rear and front differential fluid, transfer case fluid, and transmission fluid were changed recently. It makes noise even the car in park and neutral, and more pronounce when it in drive. When I place it in reverse, the noise is gone.

[E92William]

That almost sounds as if your fan or whatever was hitting something but it's under the car so I would go down there and check if anything is rubbing on the exhaust at all. The exhaust at least on the 328 passes right under the driveshaft so there's a very good chance if something got caught there or whatever you'd get that. Suggest a set of ramps so you can switch it back and forth between gears

[mousefarmer]

Not gonna know what it is until you get it up in the air and look with a helper. Maybe its the transmission mount or driveshaft who knows.

[Glene]

Originally Posted by mousefarmer

Not gonna know what it is until you get it up in the air and look with a helper. Maybe its the transmission mount or driveshaft who knows.

Got the car on air today. Did not hear anything under the car, but the noise is obvious in the driver seat. I'll check the shifter linkage next.

[Glene]

Originally Posted by E92William

That almost sounds as if your fan or whatever was hitting something but it's under the car so I would go down there and check if anything is rubbing on the exhaust at all. The exhaust at least on the 328 passes right under the driveshaft so there's a very good chance if something got caught there or whatever you'd get that. Suggest a set of ramps so you can switch it back and forth between gears

Definitely not the fan because when I put in reverse, noise goes away. used stethoscope to listen under the car, no noise. I suspect the shifter mechanism vibrating...

Update: shift linkage is good. Still don't know what causes the noise.

[mousefarmer]

If you put hand on bottom of the transmission pan do you feel vibration when your helper switches the gears?

[Glene]

Originally Posted by mousefarmer

If you put hand on bottom of the transmission pan do you feel vibration when your helper switches the gears?

No vibration, but I think a bent flex plate is the culprit, but still don't understand why the noise even in park and neutral and pronounce in drive, but goes away in reverse..

[elchicodeleste]

Originally Posted by Glene

No vibration, but I think a bent flex plate is the culprit, but still don't understand why the noise even in park and neutral and pronounce in drive, but goes away in reverse..

Hi Glene, its been a while since this post but, did you ever solve it? its happening exactly same issue to me after replacing the flywheel. All gears grind badly except the reverse.

I would really appreciate any input.

Thanks