Cabin air system help please!

I just spent $1800 having the dealer clean up the rodent mess in the passenger cabin dashboard area of my new (6 month old) 2011 Prius Gen 3. Today I removed the upper cowl cover and installed a rodent screen over the one large air inlet opening on the passenger side which leads to the cabin air filter. This appears to be the only entry path from the engine compartment and cowl area to the cabin area but I'm not sure. I have only been able to find Patrick Wong's detailed instructions for installing rodent screen on a Gen 2 Prius and it seems to have more entry points from the cowl area to the cabin i.e. 4 0r 5?? I also screened the engine air intake. I realize that there or two vents in the rear cargo area which I still intend to screen. Does anyone know how many holes need to be rodent screened and their locations on a Pruis Gen 3?
The rodent(s) also chewed up the black rubber cover over the front hole in the cabin fan air box just above the cabin air filter. The dealer installed a new non porous air cover which completely blocks this hole. I'm not sure what the purpose of the hole and original rubber cover was but it may have been an air inlet or discharge. Does anyone know the function of the hole or where a proper replacement rubber strip cover is available? Also there is a remnant of a similar rubber strip cover under a fastener in the passenger side cowl water drain hole area - so I am trying to determine the function of that cover and where a replacement is available.
Thanks for any help and I am happy to pass on additional details of my experience so far if anyone is interested.
Bill Serres

 

See if this helps...

 

Thanks for the information RRXing. So, if I understand correctly, the black rubber cover (item 5 in the drawing) over the front hole in the cabin fan air box is a check flap inlet which is supposed to open to allow the blower to suck in some cabin air(item 3) when the main inlet control door (item 1) is in the "fresh outside air" mode. So the black rubber cover has an operational function. The dealer's solution was to cover the opening with two pieces of thick adesive backed rubber which seals the hole so no air can pass in either direction. Does anyone know if this will cause problems? Of course if my above understanding is correct I am going to ask the dealer to restore the flap to original operating condition.
Thanks again for the help.
Bill Serres

 

There shouldn't be any problem with blocking off the hole other than a (very) slight loss of efficiency. My suggestion would be to find a dealer who knows something about the cars they sell.

 

I have seen a couple of threads about this now...I mean is the Prius just REALLY suceptible to having rodents crawl inside of this or is this just a sort of "sometimes it happens" thing?

(thinking about having screen put in myself now....)

 

What size screen are you guys using as your "rodent screen". ALso, is everyone using metal? I would imagine stainless steel so rust does not occur over time? What size mesh - something like a 4 x 4 seen here? Custom Wire Cloth - Belleville Wire Cloth Co - Cedar Grove, NJ

Let me know what you guys have been using and how everything has worked out.

 

I took my outer cowling cover off recently to inspect the fresh air intake and discovered a really bad design for limiting rodents. There are 2 very loosely mounted vertical baffle plates which should be tight and snug against the cowl cover so no rodent could "push" it in and gain access to the cabin air intake. Folks, it's not the mesh that is the problem - I have a 2010 and it has OEM mesh on it already. It's those side baffles. I will post pics so you can see for yourself.

 

Hi everyone,
Sorry for this slow response to your posts. I have been busy designing and installing rodent prevention screens on my 2011 Gen 3 Prius. After spending $1800 to clean and deodorize the passenger area cabin interior I am not going to risk more rodent damage.

I am screening openings to the passenger cabin area and the engine air intake as these areas are very difficult and expensive to clean but fairly easy to effectively screen.
My research indicates that screening the 5” by 10” cabin air inlet opening through the passenger side of the “firewall” ( between the upper cowl grille and the lower cowl water collection pan) and the 2 rear “flapper” vent openings on the rear quarter panels (accessible by removing the rear cargo area floor panels) will prevent rodents from entering the cabin area. I have designed and fabricated a set of 4, ¼”mesh, 23 guage, galvanized steel screens to cover the 3 cabin openings and the 1 engine air intake opening.

The dealer who cleaned my Prius for $1800 mentioned warranty problems if screws are used and holes are drilled to install screens so my design provides non invasive methods of installing all the screens to address the warranty issue. The engine air intake and 2 rear flapper vent screens can be easily installed by a handy Prius owner. The upper cowl grille cover must be removed to install the 5” by 10” cabin air inlet screen and then reinstalled to complete the installation. This can be done by a skilled Prius owner or Prius dealer.

I don’t think it is feasible to keep rodents out of the area between the cowl grille and the water collection pan(and thus out of the passenger cabin) by improving the fit of the upper cowl grille around the windshield wipers and baffles and the fit of lower cowl water collection pan to the “firewall”. I also do not think it is feasible to screen the engine compartment. I plan to periodically check for and remove any rodents found in these reasonably visible and accessible areas. I plan to research the use of sticky pads and baits placed in the cooler areas of the engine compartment to control rodents.

In my 52 years of owning vehicles I have never experienced such an aggressive invasion of any other of my vehicles in such a short time. My previous experience has been one rodent nest in the engine area of a stored van and one rodent nest on top of the battery on a stored tractor about 5 years ago. Based on this experience I find it prudent and necessary to install screens on my Pruis.

If anyone has questions or comments please reply. If anyone wants a set of 4 custom made screens and attachment hardware for a Gen 3 Prius along with installation instructions let me know and I will provide them for a reasonable price.

Thanks, Bill Serres

 

WOW - your photos are incredibly helpful!!

 

Thanks...to get that cowling cover off, you need to remove the wiper arms. I hope my car was a fluke and that most have those vertical baffles properly in place. If not, they need to be shored up somehow.

 

Hello,
Although getting the vertical baffles properly placed is important, I do not think that reinforcing the baffles is a good way of keeping rodents out. I count 5 holes large enough for rodents to pass around the baffles in my Prius. The baffles are gasketed with half inch thick foam rubber which rodents quickly chewed up on my Pruis. The baffles are made of plastic which I believe persistent rodents can eat through. There are 10 feet of seams, cracks, and openings that would need to be sealed to keep rodents out of the area contained by the baffles, the cowl grille, the cowl water collection pan, the firewall, and the baffles - not a feasible solution in my opinion. The baffles may be effective in directing air into the cabin air intake opening but my experience is that they were ineffective in keeping rodents out of the cabin.
I have designed and installed a simple 5 inch by 10 inch metal screen cover for the cabin air intake opening in the metal firewall as an effective method of keeping rodents from entering the cabin from the cowl area. Please see attached photo for my solution. If anyone wants one of these screens and installation instructions let me know. I would appreciate comments on my solution.
Thanks,
Bill Serres

 

Good solution Bill. What would happen though if a rodent got up to that point and did not manage to get out of the intake area ahead of the mesh? If it died in there, you'd still have the smell coming in. Those vertical baffles are a weak design by Toyota, IMO. I agree though - it would be really tough to "mouse proof" the baffles themselves. Luckily, I park in a garage so this is not an issue for me.

 

Hi Greg,
Thanks for the feedback and I agree that its important to carefully consider all scenarios. With your scenario, i.e. a rodent gets in the cowl area, can’t find its way out, and dies in the cowl area.

First of all I doubt that a rodent would want to stay in the cowl area as there would not be food, shelter, or warmth there. The cowl area is the collector of water draining off the windshield and front of the car and is consequently wet. It would also be very windy if the car is in use. I think the rodent attraction would be the cabin area through the cabin air intake in the firewall where there is warmth, shelter, and maybe food!! If my cabin air intake opening screen keeps the rodent out of the cabin it can as easily find it’s way out as it found the way in, especially if I do not work too hard at improvingToyota’s baffle design.

However assuming that the rodent did get trapped and died in the cowl area, I believe I would detect the smell and when I look for the source and I could easily find it by looking in the cowl area. Then with a little more work I could remove the wiper arms and cowl grille and remove the rodents’s body (and other debris if present). That solves the problem with a modest amount of do it yourself or hired labor and/or expense.

By installing a screen on the cabin air opening in the firewall I will avoid having to spend $1800 again for rodent damage by protecting areas such as the interior of the dash which I can’t access, or even see to determine if dismantling is needed, or clean myself. I want to effectively protect the cabin interior which is full of fabrics and insulation and closer to me, the occupant, and much more difficult to clean than the cowl or engine compartment. I agree that getting the baffles more secure is a good strategy but I think I will keep my baffle effort to restoring what Toyota designed and not try to improve the baffles when I do not believe the effort will be successful in keeping rodents out of the cabin. I think it is important to pick a defensible barrier and put my effort into implementing it.

The engine compartment is easily accessible to rodents but also easily visible and accessible by opening the hood and inspecting the area. I have only experienced 2 instances of engine compartment rodent nesting in stored vehicles in 52 years and I easily found and removed these. I plan to prevent costly damage in the engine compartment with frequent inspections and by removing rodents before they settle into nest building and feeding on vulnerable components.

I have designed and installed a ¼ inch mesh galvanized steel screen on the inlet end of the engine air intake tube on my Prius. I believe this is an easy and effective solution to what theToyotadealer tells me is a common problem i.e. nesting on and plugging of the engine air intake filter.

Anyone who wants a Prius Generation 3 customized set of 3 cabin protection screens and 1 engine air intake protection screen along with installation hardware and instructions please contact me.

Thanks, Bill Serres

 

+1 to all your reasons listed above. I had forgotten that you spent $1800 in damages, and your mesh design will prevent that from happening again. If a rodent got trapped in there and died, as you say you can find it and remove it with a bit of deodorizing for the smell. A good dose of Lysol Clean Linen scent spray would take care of that. I also forgot about the engine air intake problem. I'm sure your solution to that will work just fine too.
I wish Toyota would step up to this and come up with rodent-proof designs.

 

Bill ,
If you have any more around, I would appreciate a quote on your custom solution

 

Wouldn't be easier to kill the rodents?

 

I have a 2011 PRIUS Two. I have had it for 31 months. I know there are mice in my garage. So far I have seen no evidence of them entering my car. I won't take any rodent preventive measures until I see evidence they have entered the car, which hopefully they never will.

 

That's what I try to do. I have a detached garage and mice come in. I keep mice bait laying around. Whether that has prevented them from getting in to my car I do not know but I have had my 2011 Prius Two for 31 months. No mice problems in my car so far.