Noisy Ac/heater Blower On Flow Through Setting Only

[Sam Canuck]

Hi have a strange problem that just cropped up on my 2008 IS250 with about 60,000 km. When the heater/AC blower is running on the flow-through setting only (not on recirculate) it makes a loud sound like a baseball card stuck in bicycle spokes. It stops after a few minutes but it is loud enough that I am running only on recirculate. Before I take this to the dealer, any suggestions? Please and thank you!!

[clubfoot]

With the hood open inspect the cabin air intake at the base of the windshield for debris like leaves etc. If nothing is blocking the cabin air intake follow the next step.

With your AC set to AUTO and auto pass through,....turn off your car, open the glove box, remove the plastic parcel shelf (lift and pull out from the back and side). Slide up the black plastic panel at the back of the glove box which gives access to the cabin airbox and filter assembly. If the "white door" is down and you cannot see the filter assembly,... DO NOT LIFT the DOOR!!!! You can damage the mechanism!!

Turn back on the power and operate the AC controls until the door raises!

Once you have clear access lift and remove the filter and inspect for leaves or sucked in debris. Replace filter if scheduled,....usually once per year.

Run the AC to see if you can hear the noise before putting everything back.

[Srini_vss]

I have the exact same problem. I checked everything you suggested with no luck. Sam did you find a solution ? Thanks

[Sam Canuck]

Hi Vankee - Sorry for the very late reply. Edward's suggestion above worked for me. I suspected that the issue might have been related to an aftermarket filter so I got an new OEM filter, followed Edward's instructions and it worked. Because I did both, I'm not certain if it was the filter or if the previous installation was at fault.

Thanks to Edward!!