MouseProofing the Prius

I take it that you're ok with the finer mesh for the inlet to the cabin air filter, but it's really the snorkel to the *engine* air filter that should have maximum air flow?

 

Again, your call, and I'm not sure. But that mesh is so fine the cross-sectional area of the air intake is getting reduced. How significantly is beyond my pay scale, I'd just keep it to minimum required (to stop rodents), rather than excessive.

 

Got it, thanks.

 

Well I’ve owned a 2009 Pruis since new, never had mice in my car. My wife has a 2011 Pruis and has had mice in her car. I told her to stop leaving the doors open when unloading item to bring in the house. Then I brought a used 2015 Pruis at the end of summer, and I just found traces of mice in my car. So I searched it and I was shocked to find Toyota Pruis have some serious problems with mice getting in. So to start with I remove the cowl on my wife’s car and wow! That was a huge opening straight into the car. Luckily I had some hardware cloth to cover the hole. As you can see the hole in the engine compartment goes directly to the top of the cabin filter. Tomorrow I will work on the rear area of the car to make it more secure.

 

I've been reading the many threads on the Prius rodent problem. Our 2010 has now had two rodent episodes this year and I want to stop them from getting in. I'm confused about exactly how they are gaining access. Both times they have been inside the HVAC system where they died. How are they getting in there? The grill for air intake is intact with no holes in it. How else can they get in? If there are openings to the air intake under the hood, that is dramatically unsafe from an exhaust gas standpoint. The HVAC intake is outside the engine compartment area for a reason. If I take off the cowling and screen the firewall openings, what good does this do if the cowling doesn't have any holes or breaks letting the mice in? Also, are there drain openings for rain and/or HVAC condensate? I know other brands of cars have had issues with that.

So again, please tell me precisely how they are getting in and how to stop it. Is this something I can do myself with my bad back and elderly joints? I used to work on cars like thirty years ago and then they got so complex and packed like a pickle jar under the hood that I stopped doing it. If there are openings I need to close from under the car I don't think I can do it.

Thanks!

 

LOL...I just returned from relocating a rodent that AGAIN was building a nest on top of the engine with white fluff he got from inside. If I recall other posts, you should be able to remove the wipers and cowling and maybe install some hardware cloth. That is my plan, and I was waiting til I was going to replace front shocks to do it..or maybe the ABS. But I may push it up. This is third or fourth time. Fortunately they never built inside and I discovered it before they had babies etc. I have two socks stuffed in stratgic nooks and apply peppermint oil, and it seems to discourage them, but in the heat it evaporated quickly. Good thing I was checking!!! The rodent issue is one reason I haven't bought a new car. I rodents are going to chew up my wires I would rather it be the gen 2 than a new EV! I frankly see no real solution to man's ancient battle with the rodent which I have been fighting most of my 70 years, but surveillance and mint and maybe some hardware cloth have sufficed for 10 years at this place. Where are the cats and rat snakes when you need them?? Haha.. Good luck with your efforts. I have once again been outwitted by a rodent. LOL Of course, some say put out poison, but I lived in a house with the stench of dead rats that died inside. No thanks!! Mint smells better and seems to work. BTW, I have had GREAT luck with these live traps with a walnut piece. From AMZ. After decades of trapping I prefer these because there is no blood and simply turn them loose down the road in the woods a couple miles away. But exclusion is the best way IF you can do it, but I have heard some say they came in the back through exhaust port in wheel well too...Don't see how, but through that little hole into the cabin air filter is a common route.

 

Yes, as always Mendel has the answer!! Thanks, ML!!

 

Hmm hadn't heard that one. By exhaust you obviously don't mean engine exhaust. So what, take off right front wheel to access this opening? Anyone have a picture of this?

 

Not sure it is exhaust or intake, but it is for cabin air. I think it is some kind of air flow port for the gen 2 that is behind the little black storage caddy under the carpet that is over rear wheel driver side. When you shut the doors, etc it allows some air to escape, but I have heard somebody complain a mouse got in there too. Also same I think on other side..maybe for the HV battery fan? But I also think that is the last place they are likely to get in as the engine compartment has so many better nooks and entrances. And also the person the reported the entrance at rear was a Prius dweller with a trunk full of food etc and camped in the woods for day where the rodents can sniff out a crumb 5 miles away!!

 

Funny, but I just watched video relating how Japan was overrun with cats, and the Japanese really love cats. NOW I know why!!!

 

I had seen that post and it's useful. However, the one thing I have not seen is images of a Gen 3 and the associated openings to be covered. I know on a Gen 2 you have to remove the wiper assembly, is that also the case with a Gen 3? Also, there have been some posts where people covered the various openings and still got rodents inside the car. Not sure how that happened.

 

@Solman636 here you’ll find link to a @NutzAboutBolts video re the removal of wipers and cowl. It’s the one about spark plug change (which requires pulling off all this stuff):

Nutz About Bolts Prius Maintenance Videos | PriusChat

 

Pulled the wiper arms and the top cowling. These pics show the only opening I could see that leads to the inside. I think I can cover this with mesh and not pull the entire wiper assembly.

 

Much easier with the cowl off, say to drill pilot holes for sheet metal screws.

that’s the target though.

 

I love me a good pilot hole. Thanks for confirming the target sir.

 

@Mendel Leisk

I'm a little late to the party, but while stealth camping one night I discovered a mouse near the brake pedal. I went to at 24 hour store and got mouse traps. He took the bait within 10 minutes. RIP. But I'm concerned he has friends.

The first two steps of Mendel Leisk mouse prevention plan seem to be:

Question #1: The Nutz about Bolts video makes it seem like removing the entire wiper motor assembly is a PITA. Is Welshdog correct when he says: "Pulled the wiper arms and the top cowling. These pics show the only opening I could see that leads to the inside. I think I can cover this with mesh and not pull the entire wiper assembly."

Question #2: What is involved in removing the engine air intake snorkel to access the engine air intake?

Thanks in advance for replies.

 

And here's a more general question.....

Many posts show mouse damage to the cabin air filter, accessible at the glove compartment. If that filter is pristine like the day it was installed, would that suggest that you don't currently have a mouse infestation? In other words, is it extremely common to have damage to the filter if you have a mouse problem at the air intake?

Yeah, I'm hoping my little friend was a one-off. I don't park in the same place very often, so I was in a high-mouse area one night, he got in, but then I drove off and is separated from all of his friends.

 

Gat a cat

 

@Johnny Cakes, regarding #1: not sure, if screening can be done without cowl removal. Maybe, but cowl removal, while tedious, is straightforward, doesn’t take that long.

Regarding #2: the engine air intake snorkel removal makes it much easier to mesh its entrance, in case rodents take up residence in the air filter box. @NutzAboutBolts video on EGR pipe cleaning shows how to remove the snorkel and air filter box. It’s video 16, in the pinned thread of his videos (in maintenance sub forum.

Another possible entrance point is the exhaust vents, under the hatch floor in both back corners. I’ve looked at them, was a little stymied as to how to screen them off. But worth doing.

 

Hey Zak-ski

Mendel is right bout the entry points and your chicken wire looks wonderful..... But...... You're not stopping them from eating the soy based wiring and totalling out your car anyway. So....... Get a cat and don't feed him too much LOL