Mouse Nightmare

One day, I found mouse droppings inside my car. I cleaned everything, laid out traps, and thought the mouse had left…but a few hot days later, a stench started emanating from the ventilating system. Took the car to the dealer and was told that they had to open up the whole dashboard. Any better suggestions? Like maybe a really powerful vacuum to suck out the mouse?

A snake to eat the mouse.

( then next week we’ll see a post from you asking how to remove a snake from your car :))

Once the mouse gets into the vents and dies, yeah, taking the ventilation system apart and cleaning it is most likely the only solution that will get rid of the smell permanently.

If you’re lucky, and the car has a cabin filter, and the mouse died on the filter, and the filter is directly above the blower motor, and you’re VERY careful, you might be able to remove the blower motor (which you can usually do without taking the dash apart), pull the filter out and let the mouse drop out the blower motor hole. Then use a fluffly rag soaked in Lysol to scrub the vent between the blower chamber and the cabin filter, and clean the blower motor thoroughly and replace the filter.

However, it’s not uncommon for the mouse to have chewed through the cabin filter and made a nest or a food cache in the blower motor, which then blows nest and food bits (and mouse bits, if the mouse died there) into the next chamber over, which is the evap chamber for the air conditioner. There, the water dripping off the evaporator and onto the food/mouse/nest bits makes a nice, nutrient rich, moist growth medium for bacteria and insect larvae and does require disassembly to fully get rid of the smell.

I have mice too. The car stinks. We have tried everything. It’s been six months. If I had some money, I’d scrap the car and get a new one.

I had a snake (yellow rat) in the car (2004 Subaru Forester) that was interested in the mice. One of my mechanic’s employees got the snake out (hope he got a bonus).

We live on acreage, so mice are omnipresent, but this is the first time they have set up housekeeping in my car. I hate it. Has anyone tried the sound device?

I don’t know about the sound devices, but a large horse riding stables used to throw a handful of moth ball in each tack house every fall. Never had a mouse problem!!!

I do the same in my little garden shed and it also keeps the ground squirrels out all summer.

You might try throwing a few under each front seat or under the front floor mats.
They hate the smell and will avoid the area. Use the moth balls not the chips.

Also check under the dash for points where they might enter. The most frequent is where you have an automatic, but there is a port where the master cylinder rod would have entered if it had a clutch. Sometimes the plug falls off and they have an open path.

I wish they would make one of those sound devices for flies, that ran off batteries.
I don’t dare let my windows down at a barn while I work. I’m thinking of changing my business card to “Farrier and fly Relocator”


Febreeze Air Effects Pet Odor Eliminator can help. Puff a little at the base of the windshield with the fan running.

I went through the same thing back in July. The mice had built the nest on top of my cabin filter. I was lucky as the filter was not chewed through. The “dead” smell was coming from the filter from the droppings and urine. I did not have to take the dash apart. Spraying half a can of Lysol into the cowl vent with the blower running took care of the smell. Here is the link to my discussion.

Ed B.

they have this cleaner disinfectant you can spray in the vents thats actually made for that they sell it at autozone but if the mouse died in there you probably gona have to take it apart. i had a mouse hair and mold on my evaporator where a mouse died or something and i took the dash apart and cleaned it. i couldnt get it all the way clean i almost bought a new evaporator but i sold the truck instead

How would a mouse get into the ventilation system? Can you see a hole big enough for a mouse to enter? If not, maybe the problem is just the mouse dropping on the floor. The stench is being pulled up into the ventilation system at the air intake down near the floor. If so, all you have to do is clean up the floor area of all the mouse droppings.

The other path could be the vents under the front window. Maybe a mouse has done his business while sitting there. If so, get out your shop vac and vacuum along those vents. You could try using the “blow” side of the shop vac and try to blow from a vent on the inside to force any dropping to blow out the vent under the window. Seems a lot easier than removing the dash stuff. Worth a try at least.

I know we often avoid it, but poison works best for me. There are instances where harden rodents like some squirrels may use Decon to clean their teeth, but it does work on smaller critters and they leave the car or garage to find water and die. They have literally disappeared (knock in wood) since the introduction of Decon in my garage. Special attention to keep them out of the way of pets and “good” critters but I find confining the poison in a small entrance or cage that will only allow mice to enter works…or a pet gerbil so be careful.

They usuall enter up through the fenders and in the fresh air inlet. If it is dead in there you want to get it out. Whats even worse is when they eat the wire harness. If the repair is costly I have seen both home owners and car insurance cover the repairs.

I use the ultrasound repellers in Mexico. Only buy Steren or equivalent. And, even Steren figures on how much space it keeps mice out of if wrong. Their figures indicate we need 3 in our big house. I have 8 and very few scorpions and virtually no rats or mice at all. Ultrasound needs lots of power. But, of course, the disadvantage is you need to plug and unplug every time.

Unless you park the car in a garage and fill it with ultrasound.

@SteveC76 … just curious, not sure what you mean by the mouse enters via the fresh air inlet. Usually there are two fresh air inlets for the HVAC, one (for recycled air) is inside the passenger compartment, usually down by the front passenger’s feet, and the other (for fresh air) is outside, under the windshield. Do you mean the mice crawl via the fenders into the engine compartment and squeeze into the outside vent access, but they get to it under the hood? Or do you mean the mice get inside the car via the fenders, then go into the ventilation system at the place where the HVAC gets its recycled air? That one, by the passenger’s feet, usually does have an access port big enough for a mouse to crawl into.

I’ve seen mice squeeze into the darndest places under the hood, we had evidence of a mouse right under the wipers where the wiper transmission connects to the motor on a 1990 Protoge. Snagged the transmission and made the wipers not work on a really rainy day. Easy fix but a few weeks later a mouse crawled from under the hood while we’re driving to work at 60mph and flew away in the windstream. Before that we had one appear at the base of the windshield (outside again) early one morning although I was looking in the glovebox at the time and only saw the little devil on the edge of my vision.

There is a cavity below the outside air grills, they are designed to allow water to escape out usually into the fender well. This is how the mice sneak in. Those little critters can sneak into the wildest places.