What is this screeching sound? 2012 335i F30

mousefarmer · 12-09-2020, 01:07 PM

There is a screeching sound when driving slow like first or second gear. After the doors auto lock can hear it several times. What is it?

voxumf30 · 12-09-2020, 03:11 PM

That sounds like the exhaust valve opening and closing. Someone can correct me, but I think at 0 - 2.5k rpm its closed, anything above, will open. Also depends on the drive mode / conditions your in that will change when it's open / closed. Mine is audible, but not that loud.

XxThe_RemedyXx · 12-09-2020, 05:57 PM

Exhaust flap would be my guess.

mousefarmer · 12-09-2020, 05:59 PM

The sound occurs in any drive mode (Sports, Comfort, etc). It occurs whether the engine is hot or cold. The sound sort of seems to be coming from the wheels because sometimes the sound is muffled when in a far away wheel and other times its noisier.

The wheel speed sensor or ABS sensor don't normally make such a noise, do they?

thejeremyman9 · 12-09-2020, 07:09 PM

Quote:

Originally Posted by mousefarmer

The sound occurs in any drive mode (Sports, Comfort, etc). It occurs whether the engine is hot or cold. The sound sort of seems to be coming from the wheels because sometimes the sound is muffled when in a far away wheel and other times its noisier.

The wheel speed sensor or ABS sensor don't normally make such a noise, do they?

It does sound like something brushing/scraping. Your best bet is to look for patterns:

Min/max speed?

Which corner/part of the car its coming from? Have someone sit in different parts of the car and/or listen from outside driving by.

Only when turning? More when turning one way or the other?

Are you on stock wheels/tires/suspension? I would give everything a good look over.

mousefarmer · 12-13-2020, 11:05 AM

Quote:

Originally Posted by thejeremyman9

It does sound like something brushing/scraping. Your best bet is to look for patterns:

Min/max speed?

Which corner/part of the car its coming from? Have someone sit in different parts of the car and/or listen from outside driving by.

Only when turning? More when turning one way or the other?

Are you on stock wheels/tires/suspension? I would give everything a good look over.

Min and max speed would be above 1st gear and 2nd gear.

Sound is coming from all over not just one spot. I think its different wheels.

Yes, everything stock and in good shape. It sounds more like an electrical solenoid noise and not scraping noise to me.

12-09-2020, 01:07 PM	#1
mousefarmer First Lieutenant 134 Rep 323 Posts Drives: 2007 328i, 2006 330i Join Date: Apr 2019 Location: N/A iTrader: (0)	What is this screeching sound? 2012 335i F30 There is a screeching sound when driving slow like first or second gear. After the doors auto lock can hear it several times. What is it?
	Appreciate 0 Tweet Quote

12-09-2020, 03:11 PM	#2
voxumf30 Private 13 Rep 57 Posts Drives: 2017 M2 Join Date: Feb 2019 Location: Clearwater iTrader: (0)	That sounds like the exhaust valve opening and closing. Someone can correct me, but I think at 0 - 2.5k rpm its closed, anything above, will open. Also depends on the drive mode / conditions your in that will change when it's open / closed. Mine is audible, but not that loud.
	Appreciate 0 Quote

12-09-2020, 05:57 PM	#3
XxThe_RemedyXx Colonel 967 Rep 2,658 Posts Drives: 2016 340i xDrive Join Date: Aug 2009 Location: Westchester, NY iTrader: (0)	Exhaust flap would be my guess. __________________ 2016 340i xDrive - BM3 Stage 2 93 OTS - xHP Transmission Sutphin Custom Tune - B58TU HPFP - Bilstein B14 - VRSF Catless DP - Kyostar CAI - Dinan Midpipe
	Appreciate 0 Quote

12-09-2020, 05:59 PM	#4
mousefarmer First Lieutenant 134 Rep 323 Posts Drives: 2007 328i, 2006 330i Join Date: Apr 2019 Location: N/A iTrader: (0)	The sound occurs in any drive mode (Sports, Comfort, etc). It occurs whether the engine is hot or cold. The sound sort of seems to be coming from the wheels because sometimes the sound is muffled when in a far away wheel and other times its noisier. The wheel speed sensor or ABS sensor don't normally make such a noise, do they?
	Appreciate 0 Quote