Cabin Air filter part number clarification please.

Replaced the one in my 2021 4runner today. Something had been chewing on it but no nest. When you replace it make sure the airflow arrow is pointing down. The air goes in the top and comes out the bottom.

 

Yep twice a year for me, too. If you live in a climate where you often use the recirculate function on the blower, they can get pretty nasty.

 

Thats the part number that was on mine today.

 

for EPAuto filter arrow up or down..

 

One of the benefits of the K&N version is that the cotton element is incased in a wire mesh. Pretty much chew proof.

 

When you open it you'll see the airflow arrows pointing down. It says "Air Flow" and has a down arrow. You can't miss it.

 

Mine has the arrow point ^ and says up and thats how the old one came was installed.

 

This is 10,800 miles in just at 7 months. And the new one looks smaller with larger space between the pleats.
Part #87139-YZZ10

 

Does it say Air Flow on it? f not that arrow may just be the Installation Instructions. My origional also had the arrow pointed up but Air Flow was not mentioned. The replacement I bought, not Toyota, has instructions in box the says the arrow points toward the direction of the air passing thru. If you look at the picture on post 2 of the Toyota Filter it only says up, nothing about air flow.

 

I'm pretty sure it didn't say airflow. I also watched a video that said make sure the arrow is up.

 

Mine looked like shit after 10K miles in a dry, but not a desert climate while being in a parking garage 21 hours a day. Dallas has a lot of pollen though. My engine air filter didn't look that bad, but I swapped it for an AEM dry filter. Its about half the size as the OEM. I might even go with the dry K&N cabin filter mainly because these filters are getting so expensive just like everything else.

 

https://www.youtube.com/watch?v=qL2vIw_UWeE

 

Lesson to be learned is pay attention to which filter you get. OEM will be arrows up. Knockoffs could be anything.

 

Looking at the filter medium, it doesn’t appear to me to matter which way the filter is installed?

But airflow is definitely down. So gravity can keep the debris in place.

 

This is copied from the internet so it must be true.
HVAC filter direction matters because air flows through it in one direction. While its two sides look the same, one is more porous to allow air to get inside. Otherwise, air can't pass, and the unit itself must work harder and longer, leading to higher energy consumption and efficiency loss.

 

I can see that being the case with a multi layered filter (HEPA, etc). But the single layer filters in our trucks… prob isn’t gonna make much difference. They are mostly to keep debris out of the fan.

That said, if it has an arrow on it, obey the arrow! But if it doesn’t, and it’s just a cheap single layer Amazon filter without an arrow, don’t sweat it.

 

Replaced mine with one of these recently from local Auto Zone.

Got in the rig with my daughter, a/c on, and both of us thought we smelled something funky. Checked air filter next day, and realized it was time. Glad these are easy to access.

Might look into the $16 2-pack someone posted earlier in the future to save a bit of money.

 

Thanks for this. Apparently that part number no longer is available.