335i Cowl Question

e92Rithy · 09-03-2019, 03:08 AM

Hey guys, I have recently been driving without my cowl and so far no problem. I just want to know if there is going to be any long-term problems for not having my microfilters on where my HVAC system is. Is that going to affect how my AC works or anything?

Fritzer · 09-03-2019, 03:21 AM

Get the Burger Motorsports cowl delete filters. I wouldn't run without filters, too much stuff would get in there. I just saw an E92 tonight with them and mentioned them to the owner, he said that he hasn't had any issues with them and they work well.

e92Rithy · 09-03-2019, 03:23 AM

Quote:

Originally Posted by Fritzer

Get the Burger Motorsports cowl delete filters. I wouldn't run without filters, too much stuff would get in there. I just saw an E92 tonight with them and mentioned them to the owner, he said that he hasn't had any issues with them and they work well.

I probably should. I hear about them so much and they're pretty inexpensive.

Lucvalue · 09-03-2019, 03:26 AM

Quote:

Originally Posted by Fritzer

Get the Burger Motorsports cowl delete filters. I wouldn't run without filters, too much stuff would get in there. I just saw an E92 tonight with them and mentioned them to the owner, he said that he hasn't had any issues with them and they work well.

+1

NoGuru · 09-03-2019, 12:29 PM

The AC won't work as well as it does when you have the cowl installed. It must divert the hot air so you can suck fresh air.

ewicky · 09-04-2019, 11:32 AM

This is how a 15 year+ evaporator looks like. It's still shiny because of the microfilter blocking the dirt from outside:

Now I've got a surprise for you… This is how an evaporator from an '88 535i that didn't have a microfilter installed looks like. Can you believe that?

Picture by Baracuda / bmwslo.com.

There is no chance I would run the system without filters installed. Even if it never accumulates enough dirt to clog, any amount of debris can provide organic material for mold etc. to grow, which is where, combined with condensation, nasty aircon smells come from.

edit: It is also important to make sure the entire windshield cowl area is sealed (it's one big plenum). BMW designed it to be sealed, so that only filtered air can exist inside. The filter inlets are not ducted to the blower. For example, I lost my strut bar cap so I had to seal the hole off with nice black Gorilla tape. I also noticed that my wiper arm seals were cockeyed. So fixed that too.

N55Jamaican · 09-04-2019, 12:17 PM

Quote:

Originally Posted by NoGuru

The AC won't work as well as it does when you have the cowl installed. It must divert the hot air so you can suck fresh air.

How bad is it? I just bought a pair, ready to install this weekend. But with this now I don't want to compromise my cooling, unless very minimal

NoGuru · 09-04-2019, 12:31 PM

Quote:

Originally Posted by N55Jamaican

How bad is it? I just bought a pair, ready to install this weekend. But with this now I don't want to compromise my cooling, unless very minimal

It's going to depend on your climate and how cold you want it. I guess you can try and if you aren't happy, just take them off and revert it back.

e92Rithy · 11-13-2019, 02:34 PM

Quote:

Originally Posted by ewicky

This is how a 15 year+ evaporator looks like. It's still shiny because of the microfilter blocking the dirt from outside:

Now I've got a surprise for you… This is how an evaporator from an '88 535i that didn't have a microfilter installed looks like. Can you believe that?

Picture by Baracuda / bmwslo.com.

There is no chance I would run the system without filters installed. Even if it never accumulates enough dirt to clog, any amount of debris can provide organic material for mold etc. to grow, which is where, combined with condensation, nasty aircon smells come from.

edit: It is also important to make sure the entire windshield cowl area is sealed (it's one big plenum). BMW designed it to be sealed, so that only filtered air can exist inside. The filter inlets are not ducted to the blower. For example, I lost my strut bar cap so I had to seal the hole off with nice black Gorilla tape. I also noticed that my wiper arm seals were cockeyed. So fixed that too.

I just saw this, but thank you so much for replying with the examples. Hopefully a few months didn’t do too much harm 😅

iqraceworks · 11-13-2019, 03:04 PM

Quote:

Originally Posted by Fritzer

Get the Burger Motorsports cowl delete filters. I wouldn't run without filters, too much stuff would get in there. I just saw an E92 tonight with them and mentioned them to the owner, he said that he hasn't had any issues with them and they work well.

I'm running the BMS cowl filters.....no issues at all.

09-03-2019, 03:08 AM	#1
e92Rithy Stage 2+ N54 8 Rep 80 Posts Drives: 2008 E92 335i Join Date: Jul 2019 Location: Southern California iTrader: (0)	335i Cowl Question Hey guys, I have recently been driving without my cowl and so far no problem. I just want to know if there is going to be any long-term problems for not having my microfilters on where my HVAC system is. Is that going to affect how my AC works or anything? Last edited by e92Rithy; 09-03-2019 at 03:44 AM..
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09-03-2019, 03:21 AM	#2
Fritzer No one sleep in Tokyo 945 Rep 1,507 Posts Drives: 2011 E90 328i//1995 E34 530i Join Date: Oct 2018 Location: San Diego, California -> Austin, Texas iTrader: (3)	Get the Burger Motorsports cowl delete filters. I wouldn't run without filters, too much stuff would get in there. I just saw an E92 tonight with them and mentioned them to the owner, he said that he hasn't had any issues with them and they work well. __________________ 2011 E90 328i, 1995 E34 530i, 1992 E32 740i, 1991 E34 525i
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09-03-2019, 12:29 PM	#5
NoGuru Major 772 Rep 1,418 Posts Drives: 335is Join Date: Apr 2017 Location: MI iTrader: (0) Garage List 2021 Chevy Silverad ... [0.00] 2002 Jeep Cherokee [0.00] 2014 CTS [0.00] 2011 335is [0.00]	The AC won't work as well as it does when you have the cowl installed. It must divert the hot air so you can suck fresh air. __________________ 2011 335is DCT BQ Tuning / BMS CAI / VRSF kittyless DP's / Synapse BOV and charge pipe / 7" VRSF Race FMIC / Walbro 535 and 450 on BMP4 / E90 tune / Diff Brace / PR Coils / Relocation Inlets / DAW Stage3+ Turbos / MMP port injection / xHP Stage 3 / FPR and -6 fuel lines
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09-04-2019, 11:32 AM	#6
ewicky Lieutenant 204 Rep 525 Posts Drives: '07 335xi 4D AT Join Date: Jan 2017 Location: Seattle, WA iTrader: (0)	This is how a 15 year+ evaporator looks like. It's still shiny because of the microfilter blocking the dirt from outside: Now I've got a surprise for you… This is how an evaporator from an '88 535i that didn't have a microfilter installed looks like. Can you believe that? Picture by Baracuda / bmwslo.com. There is no chance I would run the system without filters installed. Even if it never accumulates enough dirt to clog, any amount of debris can provide organic material for mold etc. to grow, which is where, combined with condensation, nasty aircon smells come from. edit: It is also important to make sure the entire windshield cowl area is sealed (it's one big plenum). BMW designed it to be sealed, so that only filtered air can exist inside. The filter inlets are not ducted to the blower. For example, I lost my strut bar cap so I had to seal the hole off with nice black Gorilla tape. I also noticed that my wiper arm seals were cockeyed. So fixed that too. Last edited by ewicky; 09-04-2019 at 11:38 AM..
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