I have a 2016 Toyota Venza. This is the last year of the Canadian model and I know there was not a US model that year. I park it outside and do not have anywhere to park it inside.

When air conditioning season started this year I heard a strange fluttery noise from the vents that I did not hear when heating. Since I was headed in to the dealer for an oil & filter anyway, I had them check and they showed me an absolutely shredded cabin air filter. The noise was streamers of shredded filter blowing in the air-conditioned breeze. They blamed a mouse or squirrel for the damage, and replaced the filter. They also said you can't put screening over the intake because leaves might catch on it and then something mysteriously bad would happen.

Within weeks I heard the noise again. We pulled the filter ourselves and yup, it's shredded. My first thought is just to leave it out. But maybe that would mean dust and stuff getting into my air-conditioning? If so, that's happening now since there's a 3 inch hole in the centre of the filter.

How urgent is it to replace this filter? And if it is urgent, how can I stop rodents from shredding it? This never happened with my Corolla, my Vibe (basically a Matrix), my GM van (spit!), my Chrysler van, or the other small Toyota I bought 30 years ago and can't remember the model.

  • Welcome to our humble abode. One way you could possibly tell if it was rodents would be to see if all of the pieces of the filter were there. Shredded or not, if you can put it back together, it's very doubtful a rodent had anything to do with it. The filter material would work pretty good for bedding, so they'd not only be shredding it, they'd be using it as well. Commented Jun 22, 2017 at 17:26

4 Answers 4


The cabin air filter is meant to just protect your lungs. It keeps out dust pollen and what not. In the great scheme of things cars only recently got them (in the last 10 to 15 years).

A suggestion is to get a piece of metal screen material. Similar to what window screens use but metal (older windows used this). Cut it to the size of the filter and insert it over the filter on the side that's getting eaten. The screen is fairly thin.

This may keep the rodents at bay for at least a while.


"Does the cabin air filter protect anything other than my lungs?"

Yes, it protects the Evaporator from contamination that reduces cooling performance. Best thing they ever did for AC-Heater systems in motor vehicles.


Cabin air filters are optional. Lots of cars do not have them. Some manufacturers made this a dealer installed item.

As a matter of convenience, the filter helps reduce dust and other particulate from entering the cabin of the vehicle. Not have a cabin air filter is no worse on your lungs than standing out side your house breathing.

I am not 100% sold on rodents being the cause, unless this vehicle sits for months at a time. If the hole is in the exact same location each time, and there is no excrement in the air box, it is probably not a rodent.

I would suggest you check how close the filter is to the fan. If it is close, the fan, or something stuck in the blades, may be hitting the filter and shredding it.


Regarding putting screen in the intake area, what can happen is that leaves collect against it, get wet, the screen holds the moisture and wet materials there and you get mold and mildew building up.

Regarding what the filter protects - so some degree it protects the squirrel cage fan from dust which can cause a failure of the fan. It theoretically isolates the cabin from vermin and insects (obviously that can fail).

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