noisy blower motor on high

doughboy650gc · 01-31-2023, 08:29 PM

Hi everyone wanted to ask if anyone has experienced a noisy blower motor when in the highest settings. Sounds normal during lower speeds once you bump it up it becomes noisy behind the dash. Let me know if anyone has experienced this and if taking down the blower motor to inspect is complicated

scubachris · 02-01-2023, 07:19 AM

hi,
taking the blower motor out is VERY delicate...
if you want to ter it,open the bonnet (hood) at the back of the engine bay at the top there are 2 strenthening tubes,from under the windscreen plastic scuttle panel to each of the strut tops,
first you need to remove the right hand platsic trim in the corner which buts up to the windscreen.then you will be able to remove that right hand strengthrnin tube which goes to the strut top.

you will now see a large flat box type lid.approx 300mm x 200mm ish.there is a coarse filter foam on the front side,and an auc sensor..be carefull of the sensor,its fastner breaks eaisily..you need to remove the 4 torx screws that hold the big lid on.
the coarse filter is worth cleaning,
after you remove the big lid you will see the fan motor and the recirculate vent flaps..these vent flaps just sit in position and are not fastened in ! also at the end of the vent flaps are drive gears which if removed must be put back in correct position or the vent will not fully open or close.
you can see the ends of the motor shaft,it might be worth lubricating the bearings (as long as they are not sealed bearings)with light oil.dont put too much oil on as you will smell it inside the car also end of line resistor is in there..
check the fan blades for any scuff marks where it might be catching..
do not operate the fan with the box lid off !
the only other possible cause of the noise is something might have been dropped into an air vent and the fan on low isnt powerfull enough to pick it up but the fan on high might be.
also worth taking the lid off the pollen filters box and removing the pollen filters then turn the fan up..the pollen filters are replaced for maintenance and as it gets disturbed it might not have been re fitted correctly.

Opie55 · 02-01-2023, 08:12 AM

Quote:

Originally Posted by doughboy650gc

Hi everyone wanted to ask if anyone has experienced a noisy blower motor when in the highest settings. Sounds normal during lower speeds once you bump it up it becomes noisy behind the dash. Let me know if anyone has experienced this and if taking down the blower motor to inspect is complicated

Noisy in what way? Chances are the motor itself is going bad. But you also may have sucked some crud in there.

scubachris · 02-01-2023, 08:24 AM

the only place the blower motor sucks air in is through the coarse faom filter on the front edge of the heater motor box..this foam filter wouldnt let anything through it that was big enough for a naked eye to see..anything dust wise that does get through is stopped by the finer pollen filters...there is no other point in the system at which a foreign body could get in apart from dash outlet vents.
it could be the motor itself but i would have thought it would squeel at all speeds..it is possible though..i guess the higher the milage the more likely.
if you do take the motor out to replace it take some pics with your fone and use tippex or marker pen to mark the drive wheels ect.
good luck.

Qsilver7 · 02-01-2023, 09:18 AM

Quote:

the blower motor sucks air in is through the coarse faom filter on the front edge of the heater motor box..this foam filter wouldnt let anything through it that was big enough for a naked eye to see..

The coarse filter that protects the blower motor in the engine bay may be the problem. It can become brittle and break apart and the debris from the filter can create an abnormal hum as the bits get ripped, tossed, and broken apart around the top of the blower mower.

You may want to check to see if that coarse filter is starting to disintegrate and is the cause of your issue. The cover w/coarse filter is #1 in the diagram below:

There is a great video on YouTube that shows how to access and replace this coarse filter. The video is for an f01 7 series...but our F06/f12/f13 HVAC blower is set up the same way. I"ll try to see if I can find that video and post it here.

EDIT: I found the video (which is by an old friend from the e38 Bimmerboard forum days...Edwin from the Netherlands). He also recorded the sound coming from the blower at the beginning of the video which may help to determine if it is the same sound the OP is hearing...then goes on to show how to access and remove the cover:

doughboy650gc · 02-06-2023, 09:08 PM

Thank you for posting the video. that is exactly the noise I have in my car. Ill fix it when I take it out of winter storage

rorz12 · 02-07-2023, 12:23 AM

Quote:

Originally Posted by doughboy650gc

Thank you for posting the video. that is exactly the noise I have in my car. Ill fix it when I take it out of winter storage

Yep. I did this 2 weeks ago. Same annoying noise after you bump up fan to 4+. Took the blower apart and low and behold, there was a single dry leaf sitting in the blower spindle. Put it back together and it fixed the issue. Leaf got in there cause there was nothing left of the shitty filter. Picked up a new housing lid from dealer that comes with a redesigned filter (the new one is white). Yet to install it though.

Qsilver7 · 02-07-2023, 08:33 AM

Quote:

Originally Posted by doughboy650gc

Thank you for posting the video. that is exactly the noise I have in my car. Ill fix it when I take it out of winter storage

DerBosewicht · 02-08-2023, 12:09 PM

I have same noise!! Did anyone notate the part number?

Qsilver7 · 02-08-2023, 06:05 PM

Quote:

Originally Posted by DerBosewicht

I have same noise!! Did anyone notate the part number?

Any of the online part database sites can quickly be accessed to give the part number for the cover w/coarse filter. It will be found in the HEATER/AC diagrams.

FlyinLowSD · 02-10-2023, 03:26 AM

Hey great response post gents, especially video reference. One for the back pocket here. Thanks!

D'Mann · 02-22-2023, 06:12 PM

Here is a video on a F07/F10 where they removed the entire blower housing. I am glad I watched this one, because it shows the location of the blower resistor (bottom of the fan housing). I was told it was under the dash, and would have taken bottom of the dash apart to get to it.

I wish I had known this before getting in there over the weekend and changing the fan. It would have saved me some time to do it all at once when the resistor comes in next week. But I can do the job in 30-40 minutes now.

Just goes to show how much the stealers make off repairs.

D'Mann · 03-01-2023, 08:12 PM

Did the swap on the fan resistor after work today. Took 33 minutes. from me leaving my desk (office is in my house) until I finished washing my hands.

01-31-2023, 08:29 PM	#1
doughboy650gc First Lieutenant 21 Rep 365 Posts Drives: 2013 650i grand coupe Join Date: Aug 2016 Location: massachusetts iTrader: (0)	noisy blower motor on high Hi everyone wanted to ask if anyone has experienced a noisy blower motor when in the highest settings. Sounds normal during lower speeds once you bump it up it becomes noisy behind the dash. Let me know if anyone has experienced this and if taking down the blower motor to inspect is complicated
	Appreciate 0 Tweet Quote

02-01-2023, 07:19 AM	#2
scubachris Private 11 Rep 60 Posts Drives: bmw f13 640d Join Date: Jan 2023 Location: north yorkshire iTrader: (0)	hi, taking the blower motor out is VERY delicate... if you want to ter it,open the bonnet (hood) at the back of the engine bay at the top there are 2 strenthening tubes,from under the windscreen plastic scuttle panel to each of the strut tops, first you need to remove the right hand platsic trim in the corner which buts up to the windscreen.then you will be able to remove that right hand strengthrnin tube which goes to the strut top. you will now see a large flat box type lid.approx 300mm x 200mm ish.there is a coarse filter foam on the front side,and an auc sensor..be carefull of the sensor,its fastner breaks eaisily..you need to remove the 4 torx screws that hold the big lid on. the coarse filter is worth cleaning, after you remove the big lid you will see the fan motor and the recirculate vent flaps..these vent flaps just sit in position and are not fastened in ! also at the end of the vent flaps are drive gears which if removed must be put back in correct position or the vent will not fully open or close. you can see the ends of the motor shaft,it might be worth lubricating the bearings (as long as they are not sealed bearings)with light oil.dont put too much oil on as you will smell it inside the car also end of line resistor is in there.. check the fan blades for any scuff marks where it might be catching.. do not operate the fan with the box lid off ! the only other possible cause of the noise is something might have been dropped into an air vent and the fan on low isnt powerfull enough to pick it up but the fan on high might be. also worth taking the lid off the pollen filters box and removing the pollen filters then turn the fan up..the pollen filters are replaced for maintenance and as it gets disturbed it might not have been re fitted correctly.
	Appreciate 0 Quote

02-01-2023, 08:24 AM	#4
scubachris Private 11 Rep 60 Posts Drives: bmw f13 640d Join Date: Jan 2023 Location: north yorkshire iTrader: (0)	the only place the blower motor sucks air in is through the coarse faom filter on the front edge of the heater motor box..this foam filter wouldnt let anything through it that was big enough for a naked eye to see..anything dust wise that does get through is stopped by the finer pollen filters...there is no other point in the system at which a foreign body could get in apart from dash outlet vents. it could be the motor itself but i would have thought it would squeel at all speeds..it is possible though..i guess the higher the milage the more likely. if you do take the motor out to replace it take some pics with your fone and use tippex or marker pen to mark the drive wheels ect. good luck.
	Appreciate 0 Quote

02-06-2023, 09:08 PM	#6
doughboy650gc First Lieutenant 21 Rep 365 Posts Drives: 2013 650i grand coupe Join Date: Aug 2016 Location: massachusetts iTrader: (0)	Thank you for posting the video. that is exactly the noise I have in my car. Ill fix it when I take it out of winter storage
	Appreciate 0 Quote

02-08-2023, 12:09 PM	#9
DerBosewicht Problem Solver 113 Rep 416 Posts Drives: 640i Gran Coupe Join Date: Jan 2018 Location: TX iTrader: (1)	I have same noise!! Did anyone notate the part number?
	Appreciate 0 Quote

02-10-2023, 03:26 AM	#11
FlyinLowSD Tinker 34 Rep 154 Posts Drives: 2017 640i GC,1994 300ZX MT 2+2 Join Date: Jul 2022 Location: California iTrader: (0)	Hey great response post gents, especially video reference. One for the back pocket here. Thanks!
	Appreciate 0 Quote

02-22-2023, 06:12 PM	#12
D'Mann Private First Class 24 Rep 113 Posts Drives: 2015 650i GC - M Sport Join Date: Jun 2020 Location: NC iTrader: (0)	Here is a video on a F07/F10 where they removed the entire blower housing. I am glad I watched this one, because it shows the location of the blower resistor (bottom of the fan housing). I was told it was under the dash, and would have taken bottom of the dash apart to get to it. I wish I had known this before getting in there over the weekend and changing the fan. It would have saved me some time to do it all at once when the resistor comes in next week. But I can do the job in 30-40 minutes now. Just goes to show how much the stealers make off repairs.
	Appreciate 0 Quote

03-01-2023, 08:12 PM	#13
D'Mann Private First Class 24 Rep 113 Posts Drives: 2015 650i GC - M Sport Join Date: Jun 2020 Location: NC iTrader: (0)	Did the swap on the fan resistor after work today. Took 33 minutes. from me leaving my desk (office is in my house) until I finished washing my hands.
	Appreciate 0 Quote