Something stuck in HVAC fan

Sasquartch · 08-23-2017, 05:12 AM

On and off I've had a noise from the heater fan in my 328i

It sounds like a piece of paper or leaf or something interfering with the fan blades, it's definitely the fan as the speed of the noise changes with the speed of the fan

It was quite loud on the way home last night but after pressing MAX it went away. However I'm sure whatever is causing the noise is still in there and will return at some point.

I thought about taking the microfilter out to have a look but would the fan blades be visible from there ?

Any suggestions welcome

JustChris · 08-23-2017, 06:17 AM

Quote:

Originally Posted by Sasquartch

On and off I've had a noise from the heater fan in my 328i

It sounds like a piece of paper or leaf or something interfering with the fan blades, it's definitely the fan as the speed of the noise changes with the speed of the fan

It was quite loud on the way home last night but after pressing MAX it went away. However I'm sure whatever is causing the noise is still in there and will return at some point.

I thought about taking the microfilter out to have a look but would the fan blades be visible from there ?

Any suggestions welcome

If it's in warranty take it in. Dealer can sort, hire car for a day etc etx

Phoenixcat · 08-23-2017, 06:28 AM

I?ve got something similar in my car, I hear a noise which is only when the fan is on.
My car not in warranty, is it easy to access the fan to clean?

Sasquartch · 08-23-2017, 06:36 AM

Quote:

Originally Posted by JustChris

If it's in warranty take it in. Dealer can sort, hire car for a day etc etx

I only have warranty with 250 XS so wouldn't be worth going down this road

If it's something simple to do myself will be less hassle all round if I can do it myself

Just wondering if anyone has any experience of solving a problem like this before

Revoltos · 08-23-2017, 06:58 AM

I think this issue could go two ways.
There is a recall (although BMW refuse to call it a recall instead they call it a technical enhancement) for a resonance issue in which vibrations are transmitted down the air con hose in the engine bay and through the bulk head. The fix is to jubilee clip a dirty great weight around the hose to break the harmonic. I thought anything newer than a 15 plate had a later hose design? Could be wrong.

The second fix is leaves etc in the fan blower assembly. To remove and check, take of the cover underneath the glove box above the passenger foot well. You will see a round shaped chunky piece of black plastic nearer the A post side. Undo the multi plug and remove the three torque screws and it will drop down. Just hoover up any debris you see and spin the motor by hand to see if it has noisy bearings, lube the spindle with some spray grease if you can. If you haven't done in a while you could easily change the pollen filter at the same time. That's about it.

I've done both the above to my 13 plate and it fixed certain noises. Just wind noise left to deal with now.

Sasquartch · 08-23-2017, 07:25 AM

Thanks
Exactly the sort of advice I was hoping for.

Sasquartch · 09-02-2017, 05:45 AM

Finally got around to this today.

First removed the lower trim (2 x 10mm bolts) and disconnected the puddle light and aux power connectors.

I removed the three torx (T20 ?) screws and unclipped the microfilter

Then undid the three screws holding the fan motor in, I didn't bother disconnecting it as there was enough slack in the wiring.

Thanks to Revoltos for his post above

Quite a few leaves in there and also the pollen filter had lots of leaves so a good hoover up in order.

Put it all back together, the lower panel is a bit fiddly to get back in but just needs a bit of patience.

Changing the microfilter is so straight forward I cannot believe how much of a big deal BMW make about having it changed at service.

I also went under the bonnet and carefully hoovered up any dead leaves in the bulkhead area on both sides.

I thought it unusual that the outside air is drawn in through the fan and then pushed through the microfilter, in contrast other cars I've had (E39 and Galaxy) the filter was on the outside so the fan would only be pumping filtered air. So seems it will always be prone to getting foreign objects into the fan blades.

Anyway, hopefully will be OK now although with autumn coming I can see it happening again as there are a lot of trees around my house

M135ier · 11-02-2018, 10:54 AM

I also encountered this problem. Ended up finding a parking ticket in the blower!
https://photos.app.goo.gl/j6WN8vP9VipmE9D7

davethefish · 11-02-2018, 12:47 PM

I've had this issue on and off for the last 5 years.
it's been in BMW twice for an 'in warranty' fix and once outside of warranty for which they charged me £100

Emptied the fan out myself the last few times, but still get a noise occasionally when going down hill with the heater on.

I thought the fix was to fit mesh to the inlet area under the bonnet preventing leaves getting in?
But I didn't notice anything different after the repairs had been done.
But it seems to be doing it a lot less recently...

M135ier · 11-04-2018, 10:24 PM

on my 2013 F20 M135i there is a plastic grid/meshover the blower intake. I have no idea how the parking ticket could've made it's way into there given the mesh was in place.. Luckily for me the icket in the blower was the source of the problem but just be aware that even with the cover in place shite can still get in there somehow.

08-23-2017, 05:12 AM	#1
Sasquartch Major 606 Rep 1,455 Posts Drives: 520i G30 Join Date: Aug 2016 Location: Herts iTrader: (0)	Something stuck in HVAC fan - how to access ? On and off I've had a noise from the heater fan in my 328i It sounds like a piece of paper or leaf or something interfering with the fan blades, it's definitely the fan as the speed of the noise changes with the speed of the fan It was quite loud on the way home last night but after pressing MAX it went away. However I'm sure whatever is causing the noise is still in there and will return at some point. I thought about taking the microfilter out to have a look but would the fan blades be visible from there ? Any suggestions welcome
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08-23-2017, 06:28 AM	#3
Phoenixcat Private First Class 39 Rep 102 Posts Drives: BMW 330d M-Sport F31 Join Date: Oct 2016 Location: London iTrader: (0) Garage List 2022 Tesla Model Y [0.00] 2012 BMW 330D [9.00]	I?ve got something similar in my car, I hear a noise which is only when the fan is on. My car not in warranty, is it easy to access the fan to clean?
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08-23-2017, 06:58 AM	#5
Revoltos Second Lieutenant 53 Rep 268 Posts Drives: BMW F30 335i Join Date: Apr 2017 Location: England iTrader: (0)	I think this issue could go two ways. There is a recall (although BMW refuse to call it a recall instead they call it a technical enhancement) for a resonance issue in which vibrations are transmitted down the air con hose in the engine bay and through the bulk head. The fix is to jubilee clip a dirty great weight around the hose to break the harmonic. I thought anything newer than a 15 plate had a later hose design? Could be wrong. The second fix is leaves etc in the fan blower assembly. To remove and check, take of the cover underneath the glove box above the passenger foot well. You will see a round shaped chunky piece of black plastic nearer the A post side. Undo the multi plug and remove the three torque screws and it will drop down. Just hoover up any debris you see and spin the motor by hand to see if it has noisy bearings, lube the spindle with some spray grease if you can. If you haven't done in a while you could easily change the pollen filter at the same time. That's about it. I've done both the above to my 13 plate and it fixed certain noises. Just wind noise left to deal with now.
	Appreciate 1 Phoenixcat38.50 Quote

08-23-2017, 07:25 AM	#6
Sasquartch Major 606 Rep 1,455 Posts Drives: 520i G30 Join Date: Aug 2016 Location: Herts iTrader: (0)	Thanks Exactly the sort of advice I was hoping for.
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09-02-2017, 05:45 AM	#7
Sasquartch Major 606 Rep 1,455 Posts Drives: 520i G30 Join Date: Aug 2016 Location: Herts iTrader: (0)	Finally got around to this today. First removed the lower trim (2 x 10mm bolts) and disconnected the puddle light and aux power connectors. I removed the three torx (T20 ?) screws and unclipped the microfilter Then undid the three screws holding the fan motor in, I didn't bother disconnecting it as there was enough slack in the wiring. Thanks to Revoltos for his post above Quite a few leaves in there and also the pollen filter had lots of leaves so a good hoover up in order. Put it all back together, the lower panel is a bit fiddly to get back in but just needs a bit of patience. Changing the microfilter is so straight forward I cannot believe how much of a big deal BMW make about having it changed at service. I also went under the bonnet and carefully hoovered up any dead leaves in the bulkhead area on both sides. I thought it unusual that the outside air is drawn in through the fan and then pushed through the microfilter, in contrast other cars I've had (E39 and Galaxy) the filter was on the outside so the fan would only be pumping filtered air. So seems it will always be prone to getting foreign objects into the fan blades. Anyway, hopefully will be OK now although with autumn coming I can see it happening again as there are a lot of trees around my house Attached Images
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11-02-2018, 10:54 AM	#8
M135ier New Member 2 Rep 13 Posts Drives: M135i Join Date: Sep 2018 Location: Salzburg iTrader: (0)	I also encountered this problem. Ended up finding a parking ticket in the blower! https://photos.app.goo.gl/j6WN8vP9VipmE9D7 Last edited by M135ier; 11-02-2018 at 11:11 AM..
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11-02-2018, 12:47 PM	#9
davethefish Captain 131 Rep 664 Posts Drives: 2012 F30 320i Sport Join Date: Oct 2011 Location: Bedworth iTrader: (0)	I've had this issue on and off for the last 5 years. it's been in BMW twice for an 'in warranty' fix and once outside of warranty for which they charged me £100 Emptied the fan out myself the last few times, but still get a noise occasionally when going down hill with the heater on. I thought the fix was to fit mesh to the inlet area under the bonnet preventing leaves getting in? But I didn't notice anything different after the repairs had been done. But it seems to be doing it a lot less recently... __________________ MOD's/DIY list Bonnet Badge Repacement, LED Door Sills, 35%VLT Window Tinting, 442m alloys, Stainless Steel Pedals, Front and Rear Disk Replacement, GTechniq C1 Detail, Gladen HIFI upgrade, LED DRL's, 90mm Stainless Tailpipe, Complete Leather Reupholstery.
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11-04-2018, 10:24 PM	#10
M135ier New Member 2 Rep 13 Posts Drives: M135i Join Date: Sep 2018 Location: Salzburg iTrader: (0)	on my 2013 F20 M135i there is a plastic grid/meshover the blower intake. I have no idea how the parking ticket could've made it's way into there given the mesh was in place.. Luckily for me the icket in the blower was the source of the problem but just be aware that even with the cover in place shite can still get in there somehow.
	Appreciate 0 Quote