Cabin Filter direction 2004 Lexus RX330

lexus
filters
330

#1

I replace the cabin filter on my RX330, but am not clear on which direction the air flows. Is it upward or downward? I called Lexus and the tech said it flows downward, but if I put my hand in the filter cavity and tun on the fan, it feels like it is blowing upward.


#2

Its downward. The fan is drawing air from a port located under the cowling (just in front of the windshield) to the duct work located under the dash. I’m not sure why you feel like its blowing upward, it may be due to a low pressure situation you create whit the cavity open or it’s actually drawing air into the system from the opening you put your hand in, giving you that sensation.

The only other explanation would be if your fan was turning backwards, but then you wouldn’t feel any air blowing out your vents.


#3

When you took the old filter out, do you recall which side was “dirty” and which side was clean? Feeling air flow by hand can be deceptive. Can you figure out a way to create some “smoke” safely? Perhaps you hold a feather or very light piece of paper in the area to “see” the airflow direction. If not, put the new filter in with your best guess. If you get good airflow from the fan in the top vents then you’ll be OK. Next time you change the filter you can be sure to determine the dirty side to be sure of the airflow.


#4

Thanks for the quick replies! I didn’t think to look at the old filter when I took it out; just tossed it. The downward direction seemed intuitive to me, and that’s the way I had installed it. It is downward in my Honda CRV. The Lexus manual is not so obvious, it says something about an ‘arrow’ that is printed on the Lexus replacement filter, and that arrow points up. No mention of airflow direction, though.