Mouse nest in cabin air filter

Grateful for this thread. Have a 2016 and found out serious mice problem. What clued me in was hearing what sounded like an acorn drop inside console while driving. Opened glove box to see some chewed insulation. Went to change cabin filter- yikes! Huge nest on top of filter. What is worse is mice chewed holed through filter. This allowed acorn/nest material, mice poop to drop from top side of filter through filter to below. What really worries is lots of mice turds, AND some dark brown liquid on filter bracket, filter door.... This makes me think there is some pile of mice turds oozing liquid from above filter area. (???)

• open to recommendations. Thinking something this dire might need to go to dealer ...just to inspect for any wire damage and hopefully clean poop, nest residue, etc that have dropped through large holes in cabin filter to below.
• plan: I'll spray peppermint spray on filter -not too optimistic with that. I'll also aggressively trap around vehicle- snap traps /peanut butter. (vehicle spends lots of time idle in garage)
• Hanta virus. Problem: I like to have fun. Dying of this virus does not sound like fun. Main worry:::!!!!!!!- virus spread when mouse poop stirred up and particles become airborne. Mice poop in my air vents which blow on my face which I breath. Qu: should the CDC be involved in forcing Toyota to deal with this???
• would love it if someone could film to find how mice enter. Do they jump up to vehicle? or do they have to climb tire??? this seems KEY. was in place with bed bug issue. Finally realized one just needs to bed bug proof 4 points where bed legs touch floor. This prevents them from accessing food source- (you)...and they die. In similar fashion, if mice need to climb tires ...figure some way to mouse proof tires? maybe that honda rodent tape on tires? key is finding the vulnerable vector!
• cant believe I had been breathing airborne mice poop blowing from vents. that brown liquid is so nasty.....
• feedback welcome....thanks for letting me rant.

 

You may find my post found here somewhat informative... and maybe entertaining. lol
Mouse nesting locations in the Prius Prime

In any case, from battling against mice for my previous car 2021 PP, I have concluded that nothing I do will 100% prevent the recurring infestation. In the end, I decided not to keep the car and sold it. Mice are creatures of habit, more so than humans. If they like where they have nested once, then they will come back, if they can.

Just my two cents on some points you raised.

• might need to go to the dealer... Unless your car has a mechanical problem, taking it to a dealer would be a waste of your money. They will be able to fix what is broken, but I really doubt they will do any cleaning, disinfecting, and preventing the rodent problem.
  
• I'll spray peppermint spray on filter -not too optimistic with that.... Yep, it did not work for me. The trap around the car on the other hand will be effective in reducing the population. But it will not irradicate it.
• Hanta virus. Problem... I have not read about any active infection of Hantavirus in MA or any northern states. It is extremely rare that you contract the disease from this virus. I would not worry too much about it. You can read more here: Hantavirus | Mass.gov
• CDC be involved in forcing Toyota to deal with this???... It is not Toyota specific problem. No way they will do anything to help you.
  
• would love it if someone could film to find how mice enter... A mouse can jump. Some say up to 1-foot vertical. Yep, I have seen it, they can jump up to the underbody of the PP easily. It is only 6 inches off from the ground. But of course, climbing up the tires is the easier way for them. Also if you are parked in a garage or tree overhang, then they can come down onto the car from above. There are some devices that claim to prevent rodents from entering the car, but they are very costly, and their effectiveness has not been proven. Here are a few examples:https://www.miceout.com/products/boxkat-rodent-barrier-5-x-10-kit-single-or-dual-axle-trailer High Tech one:https://www.hammertechltd.com/

The bottom line, if I were you, I would do a very thorough deep cleaning of the air vent and filter area. Do a thorough examination of the car under the hood to make sure there are no rodent damages. Try preventing mice from entering the air intake. You can do this either at the intake hole on the body or under the front window cawl. Or an easier way is by placing the hardwire cloth on the top of the filter holder to prevent them from nesting in the cabin air fitter. There are other points of egress into the cabin, so this is not total rodent-proofing. Make sure you clean the inside of the car and don't keep anything they can munch on, (any lunch or snack you had in the car can result in crumbs falling onto the floor or seats).

 

I/4” rodent mesh securely covering the cabin air intake. You’ll need to take off wipers and cowl for access.

 

Thanks! so depressing. Thoughts:

• you sold your vehicle....why? because it was specifically mouse tainted, or because a Prius is vulnerable? Too late now, you parked outside. Did you consider a 3 sided moat? filled with oil or something mice could not navigate. ? Perhaps a sheet of plywood to prop up on 4th side you enter on.
• I'm not in a position to clean air intake etc. gotta find someone who will do that. This was parked in parents garage....they have lots of mice/ chipmunks in yard- big oak tree. Think snap traps will work well in garage- will try to seal openings.
• disease. thanks for hanta virus info. Sadly, breathing airborn mouse turds/ urine particles responsible for a slew of illnesses. Air being blown on my face as it passes over such seems like rolling the dice...not to mention the gross factor. ESP where there is some brown liquid on cabin filter bracket. All I can picture is a disease filled pile of fresh turds this is leaching from. So..desperate to find someone who specializes in cleaning this issue....I'm unable myself. suggestions welcome! thanks for all your info- !

update! just called dealer. they assured me they deal with this effectively -clean vent system, blower, etc. inspect wires.... seemingly pretty reasonable $2-300. im opting for that. then will worry about prevention

 

See if you can get them to install aforementioned rodent mesh.

 

Gonna have dealer do what they do. I'll bring a chunk of hardware cloth in case they are willing to cover window cawl when they access. I can cut some to lay on top of cabin filter. (assuming that is what I do)
Seems like I may be able to also do intake hole on body. Any videos on this?

• My immediate concern is health. Mice feces carry a slew of disease, and having a fan blow through their nest full of mouse turds/ urine out onto my face seems to be maximizing exposure to potential disease.
• the initial steps I took was remove the disgusting cabin filter made nest. As mentioned, this had large holes chewed all the way through- I was alerted to problem hearing an acorn drop through the filter. So mice turds have also fallen through. I pulled out filter, vacuumed all nest material out from sides of filter, replaced filter. ...spraying liberally disinfectant. Unfortunately lots of material- turds, etc have fallen through the filter holes- dealer seems to have a 'plan' regarding this -hope they can access this and clean.
• oh, and no plans to use AC for a while
• thanks!

 

Immediately below the cabin filter housing is the blower fan assembly. While it is possible to spray some sort of disinfectant or cleaner onto it from the above, thorough cleaning will require the removal of the fan housing assembly. This is not an easy job. My understanding is that it requires evacuating the refrigerant lines of the HVAC system and the disassembly of the entire front panel.
See this post. Removing ac blower. . | PriusChat

I highly doubt any dealer will perform such cleaning at the cost you indicated. But, if it makes you feel better, and it is worth it to you to spend money on most likely just surface cleaning, then that's all it counts. At the least they should perform diagnostic testing and visual checking to make sure there are no obvious wire and hose damages. That alone may be worth the cost.

Good luck.

 

Cleaning yourself and DIY’ing the mesh install at the cabin air intake (requires removal of wipers and cowl) will almost certainly be better than setting the dealership loose on it. And a LOT cheaper.

You want to use something like this:

BLUE HAWK Garden Craft Silver Galvanized Steel Garden Hardware Cloth Rolled Fencing (10-ft x 2-ft) 280424 | RONA

Fit a piece of mesh somewhat bigger than opening, drill pilot holes and secure with sheet metal screws.

Worthwhile to do engine air intake too.

 

Video 13 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

Shows third gen wipers/cowl removal. Different, but maybe similar.

 

thanks...video essential!

 

thanks!!!...will let you know what they do. Hope they take pics- which they often do these days. So...what alerted me was acorn falling through hole in filter- apparently to blower. They told me they would check blower- $700 if they need to replace (#$@% mice) hoping they can just vacuum out what fell down there. Got the impression they feed some sort of disinfectant through the system but not sure. Yes, they said they will inspect for wire damage. Honestly, little inspection, cleaning ,disinfecting- I'm fine giving $250. Oh, killed the mouse in the garage today- huge deer mouse. I think constant setting of snap traps with peanut butter topped with delicious sunflower seeds will cure the problem. i'll screen proof what I can..... and frequently spray some peppermint/ pepper spray I bought. Will report back what dealer does. thanks!!!! so discusting dangerous thinking of mouse crap/ urine blowing on my face. Talk about begging for a disease.

 

So, went to dealer about mouse infestation. Was actually pleased with what they did.

• They clean the AC evaporator. (AC refresher kit, element air refiner)
• remove inspect and clean blower motor (acorn and debris in this-see pic)
• inspect wire harness for rodent damage

$352 total. I consider this relative good news.
I mentioned hardware cloth over cabin filter and one rep strongly advised against , since no reason was forthcoming, that will be the plan. My impression is all inside fan air funnels through cabin filter....so hardware cloth over this will at least keep the filter uncompromised should another mouse enter. It's in a garage, already caught 2 deer mice in snap traps. I'll constantly trap, and perhaps call pest control to mouse seal garage. Thanks for all the advice here very much appreciated....not the greatest news to get, but certainly could have been much worse.

 

If mesh frustrates some rodents at the filter, they're likely to just chew up something else.



Taking the wipers/cowl out and adding mesh to the body sheet metal right where they would get in to begin with is the approach more often suggested here.

 

Screening at the cabin air inlet (requires aforementioned wiper/cowl removal) is the way to go. Two other cabin egress points are at the rear corners of the car, under the hatch floor. There's two vents there that behave kind of like dryer vents, have flaps. It's maybe more of a long shot they'd enter that way, but worth screening too, especially if you've got a lot of rodents.

Personally (on our gen 3) I've don the cabin air intake, engine air intake, and have yet to do those two rear corners "dryer vents".

 

re: removing wipers /cowl and screening that inlet.....plan to do that, is there a how to video? I'm still a little wary /disgusted about the situation. Mice chewed a hole through the cabin filter so nest material, acorns and their droppings were falling into blower. They cleaned the blower, but I'm sure the pulverized droppings cover the vent ducts into the cabin. I'm aware, that disease only lives in droppings for so long...that said, the thought of that dust blowing on my face not overly delightful.

 

In post 29 I linked a 3rd gen video on cowl removal; I don't believe there's a comparable 4th gen video. The first time will be an exploration, but it's not that hard.

Attached is some Repair Manual info:

 

thanks Mendel!...much appreciated