tgh217

New SC430 owner. Want to change the cabin air filter and watched/read 4 different instructions. Two say have the air flow arrow point up and two say the arrow should be down. Please tell me which way to have the air flow arrow on the filter point. Thanks to all who make this a great forum.

jrjmac1

That’s a good question. After I bought my 2002, I changed all filters and fluids. When I removed the old cabin filter the arrow pointed up and the he new filter instructions said to have the arrow pointed up, however all the debris (there was a lot) was on the top of the filter. This was opposite of the arrow air flow. So, I’ll be interested in the answers as well.

oneround

An OEM filter should have the arrow pointing up - Lexus is trying to tell you which way it should go in, not which direction air flows.

An aftermarket filter with an air flow indicator should go in consistent with the air flow direction (usually down).

So, in most (maybe all) aftermarket cases the arrow for an aftermarket filter should point down as the air flow is from top to bottom for every car/truck I've seen.

EDIT: And if for some reason there isn't an arrow for some reason, think about air coming from the top and going down. Put the filter in so the cut end of the pleats is facing down.

jrjmac1

Great information, thanks!

tgh217

I ordered an OEM cabin air filter (2005 SC430, part # 87139-YZZ01, for those who need one) and will install it with the arrow pointing up.

Thank You for the info.

Bgw70

as Oneround said…