Help needed, 2015 RX350 with Mice!

[Les Lex 2018]

There is a two position door between the clean side of the filter and the condenser box. Under the dash air is blocked from entering the box from under the dash in Outside air mode.  In Recirc, the door opens up to air from under the dash while closing off the path from the clean side of the air filter.

Same as the way it's done in a window air conditioner. If your 350 has mice in the vehicle but they have not chewed thru the air filter, then the only way I know of is that they forced their way thru the rear exhaust vent.

IF they are on the top of the air filter, but they can't get in to the vehicle, then its the drain hole or hood hinge thing.

But then, there are things you know, and things you don't know that you don't know... Or something like that.

[Jack1944]

6 minutes ago, Les Lex 2018 said:

If your 350 has mice in the vehicle but they have not chewed thru the air filter, then the only way I know of is that they forced their way thru the rear exhaust vent.

In 13 years of having this problem, they have never eaten through the cabin air filter.  There is tons of waste and nesting material on top of it, but they have never chewed it.  And yet they die in the glove box, !Removed! all through the cabin, leave dates on the floor, have big parties every night it seems.  I wonder if the airflow layout is different in my older RX330 (2005) - I don't see the opening that you described as the "rear exhaust vent".  Is that the trapezoidal grill that you showed a photo of in an earlier post?  Is it in the floor in the back of the vehicle somewhere?  I dont seem to have any of those....  But then I am a blind old man, losing many of his faculties - it may be right there in front of my face.  thanks for your continuing help.  Tonight I have trail cams focused on the engine compartment - film at 11.

[Gamalot]

I have some things I think I know but apparently don't know as well Les. When the baby mouse fell from behind the glove box on to my wife's foot I pulled the cabin air filter out. Sure enough there were 3 dead baby mice on the top side of the filter and a nest. How one of the baby mice got from the top of the filter where his/her sibling died out and dropped on to my wife's foot is the real mystery I have never solved. My filter was completely intact and not chewed through at all and the fit in there does seem to be tight. If a baby mouse can get from the top side of the filter and drop into the passengers side floor mat from behind the glove box then that could be the path the adult mice take to get on top of the filter. Getting into the car is probably pretty simple for those critters but the path to the air duct system seems to be eluding us all. When you turn the heat blower on to warm up the car and the filter has dead mice on it the car gets a stink that requires fumigation. So much for buying a high dollar luxury vehicle that stinks of death. 

[Les Lex 2018]

I recommend you get a lo-capacity Ozone generator on a timer and run that to get rid of the smell.

Fumigation, I don't know.  Mice also will not stay in the vehicle, or will parish due to the lack of Oxygen.

Just opening the vehicle and selecting outside air should get rid of the Ozone, provided the filter is cleared.

 

Things, Gary, I could no longer do without in an RX:

Blind Spot Mirror, Radar tracking Cruise, radar perimeter auto braking/cross-track braking,

Auto-hold brakes at stop lights, Speed Limit sign reading/posting/ over the limit warning, Cooled Seats, Voice Activated Weather Radar Display, Live operator for any questions, Auto tire pressure readout, heated mirrors. Mile Range to fill-up, internet set clocks, Homelink door opener...

Some day they will offer a College degree in how to run and set all this stuff, haha...

 

 

[Gamalot]

We love the options and features but ours did not come with the remote start option. I installed an aftermarket remote start and could not be happier. It will be about 20 in the morning so push the button from inside and go out to a warm car in 10-15 minutes. One complaint other than it being a Mouse hangout is they did not offer a heated steering wheel back in 2015 and not sure if they do now. Our wheel stays freezing cold for the entire commute to and from work, about 18 miles.

My 2016 4Runner Limited never had a mouse issue but I do like the RX350 better for just cruising and running to the market type stuff.

[Les Lex 2018]

Yes, the RX is just the right size at ~4400 lb. The heated steering wheel in the 2020 is not in the bamboo wood top section of the wheel but rather in the leather wrap on either side.  That is weird.

I don't use heated wheel or seats because the RX is in an attached fully insulated garage so bottom winter temp is about 60 degrees in there.

The RX can be started now via the iPhone. It also allows you to open close all windows and doors and buzzes the iWatch if anything changes, like a brake in.

I don't really use many of those options but it is something to play with. Lexus pays all the subscriptions for that stuff for the first 3 years.

 

[RX400h]

Have you seen this article?

How to Protect Your Car From Rodents | Chewing Wires - Consumer Reports

 

[Jack1944]

1 hour ago, RX400h said:

Have you seen this article?

How to Protect Your Car From Rodents | Chewing Wires - Consumer Reports

 

Hi RX400h - thanks for the link.  I had seen this before.  So far, I have not had wiring troubles, just a messy, smelly unwanted invasion of my beautiful RX330.  Afraid to turn on the heater for fear of what odors may come out........

[Jack1944]

On 12/15/2020 at 3:16 PM, Gamalot said:

After all this time that this discussion has been going on we would think some "rocket scientist/design engineer" employed at Toyota/Lexus might have chimed in and shown us the possible route the critters could be taking. My bet is Lexus has the ability to show the entire air flow system in a simple computer generated schematic with all the other systems removed and arrows showing the flow direction. Basically just a wiring diagram but for only the air flow vent duct system.

I found a drawing of my blower housing at a parts store, but am not sure what ports go where.  Can anyone comment on the tentative red labels I have put on this drawing?  As a possible hint, the upper blower port appears triangular and is about the same shape and location as the outside air intake grill under the hood.   I  ordered a bore inspection camera and will attempt a colonoscopy on my A/C system to see just what is happening...

[Gamalot]

3 hours ago, Jack1944 said:

I found a drawing of my blower housing at a parts store, but am not sure what ports go where.  Can anyone comment on the tentative red labels I have put on this drawing?  As a possible hint, the upper blower port appears triangular and is about the same shape and location as the outside air intake grill under the hood.   I  ordered a bore inspection camera and will attempt a colonoscopy on my A/C system to see just what is happening...

Great diagram if only they would show the actual duct work and all inlet and outlet points with directional arrows of the air flow.

[Les Lex 2018]

The only visible air-intake ducts in my RX-350 are under each of the front seats.  When I put heat only to the feet area, heat comes out of the two ducts blowing on the feet of the front passenger, but no heat blowing out of the ducts under the seats. There are outlet vents on the back of the console that do that.

If you wanted to get cool air off the floor to recirculate back into the heater, that is where you would put the ducts.

Also, the air filter is separate from the condenser/heat exchanger. Exchanger is located between the center console and the fire wall.  Reason you know this is because the freon and hot water hoses exit the engine compartment and go thru the fire wall in the center.

So between the center exchanger and the filter on the far right firewall, you have a a Y valve that takes air from under the seat for recirc, or from the air filter.

The y valve could very well be part of the actual exchanger housing, but the filter is not.

[RX400h]

On 12/16/2020 at 9:35 PM, Jack1944 said:

Hi RX400h - thanks for the link.  I had seen this before.  So far, I have not had wiring troubles, just a messy, smelly unwanted invasion of my beautiful RX330.  Afraid to turn on the heater for fear of what odors may come out........

Jack, I think the article is also for just keeping rodents out of your engine bay. A couple of years ago I was visiting my Dad when I found a bunch of mouse nest insulation from his garage, in his Honda's engine bay. In his case, this happened primarily because he had almost completely stopped using his car.

I thoroughly cleaned everything out and changed the air filters. There was no smell issues afterward, as we used his car quite often during our time spent there.

[Jack1944]

The search for an entry path to the cabin continues.  I tried to make a better diagram of the ducting following Les Lex's suggestions (see attached).  When I run my RX330 heater, hot air comes out of the under-seat ducts (#18 in the diagram).  I also found the cabin exhaust vents Les described - they are slits that are cleverly built into the rear shelf supports (the shelf for the screen that can block the view into the back storage area).  Most importantly, I found that the upper lip of the cabin air filter tray has been nibbled away along most of its length, creating a 1/8 inch wide gap right above the glove box (see green dotted line in drawing).  The plastic also is somewhat bendable, possibly creating enough space for mice to enter the cabin without chewing through the air filter.  I ordered a replacement air filter tray and will try to mouse-proof it with metal strips.  This could be how rodents get into the cabin, but it still does not explain how they get on top of the filter.  I find large unbroken leaves, 1/2 inch date pits, nesting stuff - all sorts of crud that could not fit through any of the 1/8 inch air intake holes in the grills near the wipers.  There must be a large unscreened pathway to the top of the filter.

[Les Lex 2018]

Great find about the mice breaching the filter container. And the ducts under the seat being used for heat rather than return. I'm guessing that on the 2020, the system detects a passenger in the back seat before sending air to the back seat feet.  That might explain the difference as to why I got no air from that duct with heat on to the feet. Since purchased in April, no one has sat back there, come to think about it.

When you go into the outside air duct from the filter area with that special camera on a flexible cable, I'll bet you find something wrong. Still wondering about the drain line.

[Jack1944]

Results of colonoscopy on 2005 RX330.  I bought an endoscope to try to understand how mice were getting into my heating system and into the cabin.  The 8 attached photos explain what I think I learned.  To summarize, rainwater runoff from the windshield is channeled on top of a cowling that empties into large rain drain shafts that run vertically to the ground behind the wheelwells.  They are big enough that high flows of water (and leaves and waste and mice) can get into them.  There are access points for mice behind the hood hinges, where rainwater enters as well.  Previous suggestions to tape over these areas were on the right track, but the openings are irregularly shaped and hard to tape over.  Unfortunately, there are large unscreened access holes beneath the cowling where the mice can easily get from the drain shafts into a large open trough where the wiper motor and linkage is mounted.  On the passenger side of the cowling, an air grill is positioned just above where the blower fresh air intake port is located.  This is a large 3 x 15 inch hole in the firewall.  Extremely unfortunately, this entire large port is not screened off in any way from the wiper mounting trough.  So mice can just step unimpeded onto the top of the blower and immediately be sitting on the air filter.  Also, at least in my car, they had little trouble chewing through the white plastic blower housing and getting access into the cabin. They also chewed through the front of the filter tray.  My solution (hopefully) was to fasten ¼ inch galvanized screen in front of the large firewall openings that lead to the top of the blower.  After I did this, I continued to trap mice inside the car for a couple of days, since (I think) resident mice could not escape with the new screening in place.  It has been about a week now that no new mice or droppings have been found in the car.  Apparently the clever Lexus airflow layout is not unique to my car.  In Youtube videos showing how to remove the wiper cowling from other Toyotas, you can see what looks like similar, unscreened openings through the firewall to the blower

.  I also see that owners of other makes of cars have resorted to metal screening solutions.  I will post again to update the group on the success of my attempt to screen out rodents.  (And if anyone has reason to take off their wiper cowling, I would be very interested if newer RX models still have unscreened access to the blower.  It seems dumber than I can imagine, but I am not a luxury car engineer......)

[Les Lex 2018]

I read the terrific report that you put out and popped the hood on the 2020 RX350. 

Yes, you are right. I placed an AC cord thru the passenger side opening shown in the picture and sure enough, it easily slid into the air duct going to the fresh air filter.

To protect this opening from critters, there is a seal that goes all the way accross the that blocks any break-in from mice when the hood is closed.

BUT the catch is that there another short piece used to complete the seal. And the gap between the two seals is such tht you can push your finger thru the gap real easy so mice would have little trouble squeezing thur.  So there you go...  That's a problem, but with the right size piece of same kind of rubber, then that enternace gap could be blocked so it's too much trouble for the mice to chew thru it and then squeeze in.

55B0DD11-FCB8-4946-85F5-E12CF936C82B.heic 197ABDA4-B299-418C-B739-6C14462B5581.heic

[Les Lex 2018]

You can see here where the two piece rubber seals come together.

[Jack1944]

Thanks very much Les for looking at your 2020 and very clever of you to do with a piece of wire what I needed an endoscope to figure out.  I wonder why, 15 years and many complaints later, Lexus still does not think it would be useful to screen off the fresh air ports they put through the firewall?  Do they not understand that mice can chew through rubber, plastic, and even metal, given the time and opportunity? Here are some endoscope views of openings mice have made through the top of my blower housing, which is made of rather thick, hard plastic.

[Gamalot]

These Lexus vehicles are listed as Luxury vehicles but they never said they were not Luxurious for mice and other critters. Apparently, they left a few doors open!

Thanks to both Jack and Lex for finally solving this mystery for me and many others with the same problems. To be honest, my wife has hated her 2015 RX350 ever since a dead mouse fell onto her feet from behind the glovebox. The car gives her the HeBeGibees every time she gets in it and she will absolutely never buy another Lexus because of this. She calls it the "Mouse Mobile" and we have never before had this issue with any other vehicle we have owned in over 50 years.

[Jack1944]

Gamalot:  Same deal with my wife - a dead rat in the glovebox laying on top of the spiff leather Owner's Manual doesn't make one think luxury.  We were set to buy a new 2020 RX350 (envious of Les's great red one), but now we are uncertain what to do.  Searching on Google, other brands have the same problems. I do know that regardless of what we buy, I will be exploring the rodent pathways and screening them up right away, warranty or no warranty.

(BTW, if you drop the plastic plate below the glovebox (no tools needed on my 2005), you may find quite a messy nesting area, since there is a blower sound reduction pad there, made of soft and comfy white batting .  Like staying at the Ritz to a rodent, no doubt.  Perhaps that is where your little visitor fell from.  My batting had several date pits in it, since they even brought their own dinner back to their room, to eat in bed I guess.)

[Gamalot]

If you go to the second post in this thread that I started you can see the mess I had. Same as what you experienced. I had high hopes that someone from Lexus would have joined this discussion and given us some direction. Apparently after all this time Lexus could not care less and now it is you and Lex giving Lexus the real solution. There can be no doubt in my mind this has been an ongoing issue at Lexus dealership service shops from others with the same issue while still under warranty.

[Les Lex 2018]

In the dark, I stuck an LED torch into the hole where the Ac cord was previously inserted.  The inside of the air intake lit up bright indicating the opening is kind of wide.  I did the same thing on the driver side and there was no light entering the intake, indicating that there is no entry point there.

So, while the design is to obstruct or resist rodents from entering there while the hood is closed.  when the hood is open, the rodents have a clear entry point into the vehicle air intake tray that you show in the picture.  With the hood closed, they have to do a little more work to get in.  As you noted, the next obstacle should have been metal against metal so the rodents cant gain entrance to the air filter by chewing what ever it is that is left in their way.

[Brian mcgovern]

I have a 2016 RX 350. Found 1 mouse by the air conditioner condenser. I think another one died in the air vent still can’t get rid of the smell OMG.  
I have had several other cars in this garage with no issue. Wondering if it’s the design of the car. This is the second time with this car. Change the air filter and yes that’s always where they live

[Brian mcgovern]

Any thoughts where it may have died. The filter Showed a little bit of nesting but no animals in it. Any thoughts on where in the air duct system?

[Les Lex 2018]

They have an entry point under the passenger side hood hinge. See the pic. I placed a clothes pin in there to point to the little alley way they have to go up inside and get into the air filter. On this side of the clothes pin is a little square flat area where you can cut out a square piece of sticky paper designed to catch mice before they enter.

when the hood is closed, that area is blocked  to rodents by a rubber seal. But if you look at the seal in the pic, they can just wiggle between two pieces that are not bonded to each other.  So the design was there but the application was careless. So it seems.