Cabin filter observations

As if the orientation of the “Air Flow” isn’t a hard enough not to crack. I realized today that my blower was not putting out very good air on max. I recently changed the blower motor and put in an extra fancy filter with the carbon layer. I was getting virtually no air out of the front vents. It sounded like most of the air was being restricted up near the dash.

I pulled the filter out and it’s blowing like crazy now. I even tried flipping it to see if it would make a difference nope. I feel like the cheap low quality replacement flows better probably because it’s not as thick.

Has anyone else ever experienced low flow with one of these carbon enhanced filters? I’m not kidding when I say the difference is incredible running without or with a cheapie.

Does the factory filter allow for more airflow? Because this aftermarket unit really seems to restricted it.

I’m mostly just sharing this in case anyone does a search on why they’re not getting good air volume.

 

Airflow isn't known to be great on these to begin with but yea the thicker the filter media the less air is gona flow through it.

I have a K&N washable cabin filter in mine abd it flows pretty good when it's clean.

 

I noticed the issue on my truck. Two different Toyota part numbers come up for cabin filters on their parts website: one is the normal/standard factory filter and another for a carbon impregnated one. The latter is noticeably more restrictive. I removed it and installed the factory one it comes with. Here's a list that might be helpful. (Not sure why the part number(s) for the two Toyota filters link/point to an Amazon listing.)

Cabin Air Filters (2nd gen)

Toyota OEM Factory

$22 87139YZZ09 Genuine Toyota 87139-YZZ09 Cabin Air Filter

87139YZZ09
Toyota ("micronAir") Cabin Air Filter 8850801010
MANN FP-1919
Denso 453-6058
FRAM Fresh Breeze

$19 CF10374 Cabin Air Filter For 2005-2021 Toyota Tacoma, Dodge Dart, Pontiac Vibe With Activated Carbon,2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

CF10374
FRAM True Air CV10374
WIX 24871 / 24871XP

 

The carbon filters need to be changed much more often, like yearly, from what I've read. I believe that they clog quickly and the carbon does it's job by neutralizing stuff and wearing out after about that time too. I think a new filter of either kind will help the airflow problem.

 

I buy the cheapest option from rock auto and replace it before winter and after winter. May be overkill but doesn’t hurt.

 

I buy them in bulk from rock auto as well (same with engine air filters) because it's significantly cheaper. I've got like half a dozen of each WIX filters in a box in the garage and now I don't have to even think about it for years to come. They have Denso in stock as well if OEM is your thing.

 

I know what you mean. I had a customer complain about airflow right after I used one of those carbon filters and I've avoided them ever since

 

I had no idea this was a thing. I just figured they would flow the same. Definitely didn’t expect to see such a difference in negative flow after installing the carbon filter. Time to grab a couple of basic filters and can the carbon one.

 

Yep, I buy the cheap Tyc filters from Rock Auto too. I have the windows down or cracked most of the time anyways, but with the pollen seasons here it's pointless to buy expensive filters just to replace them at least twice a year, especially when I park outside. The '05s didn't even come with filters in them although they have the same system as the 4Runners and later Tacomas which did come with filters.

 

K&N is your best bet here. Washable and doesnt restrict air flow. I've been amazed at the dirty water that comes out of it when it doesnt even look dirty.

 

Yea I won't use their engine air filters (they let too much dust through) but their cabin filters work great.

 

This is good to know.

 

YES, those carbon cabin air filters are complete crap. This is one area where (in my opinion), you want the thinnest, lightest filter you can find. You only want something that will keep crap out of the blower motor. I did the same thing years ago and will never use on of those thick filters again.
Like @Dm93 said, I'd use a K&N here, but only here.

 

What benefit does the carbon provide in this application? (and realize that it's a miniscule amount of carbon that will saturate itself in a few weeks and become useless anyway)

If the HVAC is drawing fresh outside air, in general there should not be any bad smells from outside that need to be absorbed.

If the HVAC is on recirc and drawing from the cabin, but something inside the cabin is stinky and needs to be absorbed by carbon, why do you need to recirc? (and does recirc mode even go through the filter?)

The filter is there to catch debris to protect the system.

 

I take mine out during the dog days of summer when I need full air flow.

I put a new one in during allergy season (now)

A serviceable filter is a good idea, I may do that next major purchase.

 

We almost have to have filters here because the dust is terrible quite often with all the wind and dry weather, vehicles without filters especially ranch and fleet trucks, just get caked. We've replaced several because of it.

I clean mine about twice a year and it's still usually pretty dirty even though I have my windows up and use recirculate most of the time.

 

Re: air flow through filter in Recirc mode: Recirc mode does direct the incoming air through the the cabin filter. A flap in the HVAC unit behind the glove-box opens to draw air from the interior when you push the button or automatically turn the temp dial to "MAX a/c". (added around 2010)

 

I have charcoal cabin filter in both Rav 4s , the Camry & the 2015 Tacoma, no issues
Typically Fram, but also Purolator Pure One .

Can't imagine running w/o a cabin filter in No. Idaho, you're be eating dust

 

I've also run both types and haven't noticed any difference in the airflow into the cabin.