Stinky Car After Changing Cabin Air Filter

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Stinky Car After Changing Cabin Air Filter

Post by Kennedy » Sat Oct 13, 2018 3:16 pm

About 18 months ago, I dropped off for an oil change the car my teen drives. About thirty minutes later, the tech called and said he wanted to show me something when I returned for the car. I almost lost my cookies when he showed me mouse poop in my cabin air filter. Obviously, I had him replace the filter.

When I left the oil change shop, I noticed a bad smell in the car. I returned, and the tech told me it would be gone in a day or so.

Fast forward 18 months, and the smell is still there. My teen said they are used to the smell and it isn't bothersome. They've gone nose blind. For me, I have a hard time even being in the car.

I wondered if there was a dead mouse somewhere in the air conditioning system, but wouldn't it have decomposed and dissipated by now? The smell wasn't there before the cabin air filter was replaced.

What do I do?

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Re: Stinky Car After Changing Cabin Air Filter

Post by whodidntante » Sat Oct 13, 2018 3:27 pm

There are a lot of causes for bad odors. Water intrusion can cause mold/mildew and is relatively common, as is smoking and rotting food. Some odors can really linger. Does it smell of death? Is the odor always present or does it get much worse if you turn the fan on? If you think it's a dead mouse I guess you could go so far as to remove the cabin air ductwork and thoroughly clean it out, but it would not be a trivial job. It's not made to be easily removed.

I would also replace the cabin air filter again. Who knows what he put in there, and you said you noticed the smell after it was changed.

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Re: Stinky Car After Changing Cabin Air Filter

Post by DigitalJanitor » Sat Oct 13, 2018 10:43 pm

There could very well be a dead mouse in there. In my various Japanese cars, when you slide the air filter out, whatever was on top of the filter (acorns, seeds, mouse nesting material, baby mice) is scraped off by the upper lip of the filter access slot and ends up dropping down onto the squirrel cage fan (an appropriate name) below the filter. You can usually slide a hand into the the slot after the filter is out and feel around to remove any of these items that may have fallen.
Last edited by DigitalJanitor on Sun Oct 14, 2018 7:57 pm, edited 1 time in total.

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Re: Stinky Car After Changing Cabin Air Filter

Post by bowtie » Sat Oct 13, 2018 11:06 pm

The above post looks like a good explanation.
I was also wondering - if that particular make/year of vehicle could have a history of this sort of problem also? Could you find out by going to car discussion forum or going back to the service techs?

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Re: Stinky Car After Changing Cabin Air Filter

Post by imbogled » Sun Oct 14, 2018 6:47 am

If you decide to replace the filter again, please have him do it himself. Very simple procedure which typically will take less than 5 minutes to perform. Youtube videos will make it even easier to install. Purchase the filter online at eBay if available, usually great prices available. Dealers and the like usually charge around $70 and you can do it for $10-$15. Consider the possibility of a mold/mildew issue with the a/c. An important thing I have learned over the years is to turn the a/c off a minute or 2 before shutting the car off in order for the condensation to dry up/drain a bit before parking the car. It has made a huge difference in a/c smell. Good luck. Please follow up with your results.
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Re: Stinky Car After Changing Cabin Air Filter

Post by 3-20Characters » Sun Oct 14, 2018 6:58 am

A dead mouse isn’t going to smell for 18 months. If it’s mold, you can use the this method to fix. I did it and it works like a charm.

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Re: Stinky Car After Changing Cabin Air Filter

Post by gd » Sun Oct 14, 2018 7:32 am

Our dead mouse faded after leaving the car in summer sun for a month with windows left open. 18 months and there's not much left. A cheap air freshener that clips on air vent helped cover it up. I found once it started, the fan didn't make much difference when trying to figure out what/where it was. Newly-dead mice have a distinctive odor compared to mold and stuff like rotten fruit (tip--never let a rotten pumpkin drip in your car).

BTW, mice also like nesting in the engine air intake before the air filter. Worth checking it periodically, not hard to DIY. Some cars are more susceptible than others. I've taken to putting window screen over the intake of my cars when I start noticing mouse poop and food debris on the top of the engine-- it's nicely warm there cold nights, and a pretty reasonable place for a smart mouse to hang out.

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