Thinking of replacing the cabin air filter yourself?

gugin · 05-26-2021, 11:43 PM

If it's possible to push the recirculating flap past its end stop in one direction, shouldn't it be possible to pull the flap in the reverse direction to restore it to the correct side of the end stop? Perhaps using a suction hose to "grab" the flap so you can pull it.

CRuben09 · 05-27-2021, 07:06 AM

Quote:

Originally Posted by freshxdough

Quote:

Originally Posted by CRuben09

Quote:

Originally Posted by freshxdough

Worst part about it is if you accidentally end up pushing the recirculating flap past it's end stop resulting in poor air flow and even a slight air resistance/whistle that can be heard during fan operation. Ask me how I know because I did it last week when I serviced my microfilter. I've done thousands of micro filters and the G01 apparently is the only one you can possibly do this with. Yesterday I had to remove the complete glove box, passenger knee airbag and the blower fan to be able to access the flap and flip it back over. This is a known issue and there is an SIB for it. According to the SIB replacement of the complete air conditioning box is necessary. I wasn't about to take my car back to my own dealer for that lol.

What are the odds of finding your post? So, 2 weeks ago, under the regular maintenance, the service center replaced the microfilter. When I picked up the car, I immediately noticed that the fan blower wasn't as potent as before, and a whistling noise could be heard when turning on/off the A/C unit.

Is that flap located at the top of the microfilter housing? I found the one for the outside air which is I believe on the back side. I had to manually force it, so I could get more air, but if I press the recirculating button it doesn't do anything. Can you explain step by step what you did? If you can of course.

Thanks!

Step by step was described in my previous post. If you remove the micro filter and look up inside the housing you will see the flap that is sitting incorrectly, like my first photo.

I chose to try and flip the flap myself. You will need to remove the glove box with T20 torx bits. Then also remove the 3x T20 screws on the air box that are installed straight up and remove the blower fan. Then you should see what my 2nd and 3rd photos are. I had the ignition on just so there was power going to the flap motor just so I wasn't pushing against an unpowered flap. I flipped it around almost a whole 180 degrees then turned off the ignition. Turned it back on and selected and deselected recirc and watched the flap work normally again. Drove to and from work today and it's working normally now.

Thank you!

freshxdough · 05-27-2021, 10:18 AM

Quote:

Originally Posted by gugin

If it's possible to push the recirculating flap past its end stop in one direction, shouldn't it be possible to pull the flap in the reverse direction to restore it to the correct side of the end stop? Perhaps using a suction hose to "grab" the flap so you can pull it.

I don't believe a suction hose will work. From the bottom you would need to pull downwards and there's really no way to do that easily from underneath the flap. You would need to rotate it nearly 180*. I have small hands and I couldn't get in there to be able to grab it. You would have to use some long radiator pics and even then who know did you could do it cleanly without damaging the flap or the gasket. If I encounter another one in the future I will see if I can do it from the bottom knowing now which direction it needs to rotate

KL07RPH · 05-27-2021, 10:28 AM

Quote:

Originally Posted by freshxdough

I don't believe a suction hose will work. From the bottom you would need to pull downwards and there's really no way to do that easily from underneath the flap. You would need to rotate it nearly 180*. I have small hands and I couldn't get in there to be able to grab it. You would have to use some long radiator pics and even then who know did you could do it cleanly without damaging the flap or the gasket. If I encounter another one in the future I will see if I can do it from the bottom knowing now which direction it needs to rotate

Does overriding to recirculation mode (not auto) prior to changing the filter out minimize the risk of accidentally rotating the flap? Just a thought.

freshxdough · 05-28-2021, 12:48 AM

BMW documentation states to put the air into FRESH AIR mode, (recirculating air light not lit up). I'll have to do more research into this as I believe that putting into recirc would make the flap be flat against the housing and this further away from knocking it when installing the new microfilter. Although I will say, I put my air specifically into Recirc and this is what happened. So I'm sure BMW knows what they are doing. I will do it in fresh air mode next time and see how it turns out

CRuben09 · 05-28-2021, 03:11 PM

Quote:

Originally Posted by freshxdough

BMW documentation states to put the air into FRESH AIR mode, (recirculating air light not lit up). I'll have to do more research into this as I believe that putting into recirc would make the flap be flat against the housing and this further away from knocking it when installing the new microfilter. Although I will say, I put my air specifically into Recirc and this is what happened. So I'm sure BMW knows what they are doing. I will do it in fresh air mode next time and see how it turns out

I did it today. Thanks to your walkthrough it took me almost and hour to complete. The most difficult part was removing the top screw in the fan housing. Other than that, everything was pretty much straightforward. It was in fact that flap being forced all the way up.

freshxdough · 05-28-2021, 03:22 PM

Quote:

Originally Posted by CRuben09

Quote:

Originally Posted by freshxdough

BMW documentation states to put the air into FRESH AIR mode, (recirculating air light not lit up). I'll have to do more research into this as I believe that putting into recirc would make the flap be flat against the housing and this further away from knocking it when installing the new microfilter. Although I will say, I put my air specifically into Recirc and this is what happened. So I'm sure BMW knows what they are doing. I will do it in fresh air mode next time and see how it turns out

I did it today. Thanks to your walkthrough it took me almost and hour to complete. The most difficult part was removing the top screw in the fan housing. Other than that, everything was pretty much straightforward. It was in fact that flap being forced all the way up.

There should be just 3 screws holding the fan with the attached plastic housing. But once it's out it's very easy to see inside. Glad you got it figured out as well. I'd rather do this that replace the entire box.

KL07RPH · 05-28-2021, 05:29 PM

Quote:

Originally Posted by freshxdough

BMW documentation states to put the air into FRESH AIR mode, (recirculating air light not lit up). I'll have to do more research into this as I believe that putting into recirc would make the flap be flat against the housing and this further away from knocking it when installing the new microfilter. Although I will say, I put my air specifically into Recirc and this is what happened. So I'm sure BMW knows what they are doing. I will do it in fresh air mode next time and see how it turns out

That's really, really interesting. I'd figure keeping the flap closed would have less likelihood of the filter bumping it the wrong way....

Fast400 · 05-29-2021, 09:31 AM

When I made the video, I was in fresh air mode...by luck! Maybe I should mention this in the video description. Thanks!

Quote:

Originally Posted by freshxdough

BMW documentation states to put the air into FRESH AIR mode, (recirculating air light not lit up). I'll have to do more research into this as I believe that putting into recirc would make the flap be flat against the housing and this further away from knocking it when installing the new microfilter. Although I will say, I put my air specifically into Recirc and this is what happened. So I'm sure BMW knows what they are doing. I will do it in fresh air mode next time and see how it turns out

KL07RPH · 05-30-2021, 09:56 AM

Quote:

Originally Posted by Fast400

When I made the video, I was in fresh air mode...by luck! Maybe I should mention this in the video description. Thanks!

After some thought, I think I figured out BMW's rationale for putting the CC in fresh air mode. Leaving the flap open (fresh air) minimizes/prevents the risk that it erroneously over-rotates into a stuck position; if you were to accidentally bump into a wrong position during a filter swap, cycling the air mode from "fresh air" to "recirc" would simply correct the flap back into the closed position.

I'm guessing that leaving the flap closed (recirc) during a filter swap might still get bumped open, and if the system ever went from "recirc" to "fresh air" mode, that would end up forcing the flap to over-rotate "open" and get into that dreaded stuck position.

Just my own thoughts from someone who wanted (but ended up not being) an engineer

hooch888 · 06-01-2021, 02:24 PM

Quote:

Originally Posted by Yobyot

Worse, the slot the filter goes in is curved. Clearly, the engineer who designed it never had to replace it.

If BMWs were designed by engineers they wouldn't put the filter in there. My guess their "engineers" these days are drunk high school drop outs.

MX330I · 06-02-2021, 09:44 AM

They may have engineered it this way to discourage people doing DIY on their vehicles.

Alias1431 · 06-02-2021, 10:31 AM

Bingo. Alleging that BMW's were engineered by drunk high school dropouts is foolish. A huge chunk of their brand is "German Engineering." What they do has purpose, even if you don't agree with it.

Drexel_Lake · 06-02-2021, 03:53 PM

If you think that's hard you probably shouldn't be a DIYer.

CRuben09 · 06-02-2021, 06:39 PM

Quote:

Originally Posted by Drexel_Lake

If you think that's hard you probably shouldn't be a DIYer.

Not hard at all. I think is a simple DIY. If you have the knowledge on how to do it, you shouldn't have any troubles. The flap is the only complication you may experience and involve a lot of additional tasks to revert it, which makes people think is complicated to accomplish.

freshxdough · 06-07-2021, 05:03 PM

BMW have just released an SIB for this issue after microfilter replacement. No parts replacement necessary. This issue won't be caused by anything other than recently replacing the microfilter.

They had talked about it previously but actually released repair info now. Turns out exactly what i described earlier is the repair. Remove the blower fan, and push the flap back to its normal position. You then recheck it to ensure the stepper motor did not get damaged at all. May have to "readdress the stepper motors" and "reinitialize the stepper motors" but I think that will be a rare occasion.

LukBMW · 06-09-2021, 06:03 PM

Thank You for sharing.

Yobyot · 06-09-2021, 06:05 PM

Quote:

Originally Posted by freshxdough

BMW have just released an SIB for this issue after microfilter replacement. No parts replacement necessary. This issue won't be caused by anything other than recently replacing the microfilter.

They had talked about it previously but actually released repair info now. Turns out exactly what i described earlier is the repair. Remove the blower fan, and push the flap back to its normal position. You then recheck it to ensure the stepper motor did not get damaged at all. May have to "readdress the stepper motors" and "reinitialize the stepper motors" but I think that will be a rare occasion.

SIB number, please?

Big_CG · 07-26-2021, 01:12 PM

In for the SIB number- Same thing happened to me and the flap is stuck open. Any more pictures or details what flap needs to be rotated and in what direction? I dont want to brake the delicate plastic parts by forcing it.

_ink · 07-26-2021, 10:06 PM

Just completed this and took me all of 5 mins!! Took me longer to get the bloody tools out!!

freshxdough · 07-27-2021, 12:07 AM

You need to remove the microfilter again and inspect upwards into the air box. The flap that is pointing up will need to be rotated downward toward the cabin and rechecked for smooth movement. If you bring to the dealer they will be able to do all of this for you, including performing a vehicle test and test plan to recalibrate the motors to ensure everything is ok. We've seen a few vehicles where the flap pops off the rod and the flap actuator needs to be removed and installed again with the flap and rod. I think most vehicles though will be fine when gently rotating it back. You will need a long radiator pick or something as you can not physically reach it with your hands.

rob175 · 07-28-2021, 10:37 AM

LOL....so how much does it cost for the dealer to change the filter? Parts cost? "book" labor time/cost?

I'm just guessing but I doubt it would take a BMW dealers tech between 15 to 30 min TOPS. But I'd be interested to see some numbers (before I attempt to DIY and hurt my back....LOL)

05-26-2021, 11:43 PM	#23
gugin New member 318 Rep 553 Posts Drives: 2019 X3 M40i Join Date: Jan 2019 Location: Washington, DC iTrader: (0)	If it's possible to push the recirculating flap past its end stop in one direction, shouldn't it be possible to pull the flap in the reverse direction to restore it to the correct side of the end stop? Perhaps using a suction hose to "grab" the flap so you can pull it.
	Appreciate 1 CRuben09119.00 Quote

05-28-2021, 12:48 AM	#27
freshxdough BMW Elite Master Tech \| HV Gen 5 \| HV Specialist 3509 Rep 4,206 Posts Drives: 2024 iX 50 \| 2020 X3 M40i Join Date: Mar 2017 Location: Orange County iTrader: (0)	BMW documentation states to put the air into FRESH AIR mode, (recirculating air light not lit up). I'll have to do more research into this as I believe that putting into recirc would make the flap be flat against the housing and this further away from knocking it when installing the new microfilter. Although I will say, I put my air specifically into Recirc and this is what happened. So I'm sure BMW knows what they are doing. I will do it in fresh air mode next time and see how it turns out
	Appreciate 4 prototyp228.00 Fast400681.50 Chief Orman671.00 Plusforce156.00 Quote

06-02-2021, 09:44 AM	#34
MX330I Private 11 Rep 62 Posts Drives: G01 X3 30i xDrive Join Date: Dec 2020 Location: BC, Canada iTrader: (0) Garage List 2018 G01 X3 30i [0.00]	They may have engineered it this way to discourage people doing DIY on their vehicles.
	Appreciate 1 Chief Orman671.00 Quote

06-02-2021, 10:31 AM	#35
Alias1431 Lieutenant Colonel 795 Rep 1,959 Posts Drives: 2019 BMW X3 M40i Join Date: May 2019 Location: Washington iTrader: (0)	Bingo. Alleging that BMW's were engineered by drunk high school dropouts is foolish. A huge chunk of their brand is "German Engineering." What they do has purpose, even if you don't agree with it.
	Appreciate 1 Chief Orman671.00 Quote

06-02-2021, 03:53 PM	#36
Drexel_Lake Private 24 Rep 92 Posts Drives: BMW X3 M40i 330cic Join Date: May 2021 Location: South Carolina USA iTrader: (0) Garage List 2020 BMW X3 M40i [10.00] 2005 BMW 330ci [5.00]	If you think that's hard you probably shouldn't be a DIYer. __________________ 2020 X3 M40i Blue 2005 Supercharged 330ci Silver/Black vert.
	Appreciate 1 Ravenous666532.00 Quote

06-07-2021, 05:03 PM	#38
freshxdough BMW Elite Master Tech \| HV Gen 5 \| HV Specialist 3509 Rep 4,206 Posts Drives: 2024 iX 50 \| 2020 X3 M40i Join Date: Mar 2017 Location: Orange County iTrader: (0)	BMW have just released an SIB for this issue after microfilter replacement. No parts replacement necessary. This issue won't be caused by anything other than recently replacing the microfilter. They had talked about it previously but actually released repair info now. Turns out exactly what i described earlier is the repair. Remove the blower fan, and push the flap back to its normal position. You then recheck it to ensure the stepper motor did not get damaged at all. May have to "readdress the stepper motors" and "reinitialize the stepper motors" but I think that will be a rare occasion.
	Appreciate 3 CRuben09119.00 ChuckM40i-2.00 kevinkay271.50 Quote

06-09-2021, 06:03 PM	#39
LukBMW New Member 0 Rep 7 Posts Drives: BMW X3 G1 Join Date: Jun 2021 Location: UK iTrader: (0)	Thank You for sharing.
	Appreciate 0 Quote

07-26-2021, 01:12 PM	#41
Big_CG Major 185 Rep 1,482 Posts Drives: 2020 X5 Join Date: Apr 2014 Location: SWFL iTrader: (8)	In for the SIB number- Same thing happened to me and the flap is stuck open. Any more pictures or details what flap needs to be rotated and in what direction? I dont want to brake the delicate plastic parts by forcing it.
	Appreciate 0 Quote

07-26-2021, 10:06 PM	#42
_ink Jedi samurai ninja turtle 619 Rep 3,021 Posts Drives: X3 M40i 2018 Join Date: May 2012 Location: Sydney, Australia iTrader: (0) Garage List 2018 X3 M40i [0.00]	Just completed this and took me all of 5 mins!! Took me longer to get the bloody tools out!!
	Appreciate 1 Chief Orman671.00 Quote

07-27-2021, 12:07 AM	#43
freshxdough BMW Elite Master Tech \| HV Gen 5 \| HV Specialist 3509 Rep 4,206 Posts Drives: 2024 iX 50 \| 2020 X3 M40i Join Date: Mar 2017 Location: Orange County iTrader: (0)	You need to remove the microfilter again and inspect upwards into the air box. The flap that is pointing up will need to be rotated downward toward the cabin and rechecked for smooth movement. If you bring to the dealer they will be able to do all of this for you, including performing a vehicle test and test plan to recalibrate the motors to ensure everything is ok. We've seen a few vehicles where the flap pops off the rod and the flap actuator needs to be removed and installed again with the flap and rod. I think most vehicles though will be fine when gently rotating it back. You will need a long radiator pick or something as you can not physically reach it with your hands.
	Appreciate 1 Chief Orman671.00 Quote

07-28-2021, 10:37 AM	#44
rob175 Major 688 Rep 1,114 Posts Drives: BMW X3 xiDrive30 Join Date: Feb 2020 Location: Illinois iTrader: (0)	LOL....so how much does it cost for the dealer to change the filter? Parts cost? "book" labor time/cost? I'm just guessing but I doubt it would take a BMW dealers tech between 15 to 30 min TOPS. But I'd be interested to see some numbers (before I attempt to DIY and hurt my back....LOL)
	Appreciate 0 Quote