How To Get Rid of The Mouse Pee Smell For Good

[MR_Loyale]

How To Get Rid of The Mouse Pee Smell For Good

 

DISCLAIMER: The author assumes no liability for any actions a reader may perform after reading this article. The reader by virtue of reading the material agrees to hold harmless he author, the website, website owner and any other persons. This procedure involves potential contact with biological (mouse pee and infested bedding) and chemical agents. If you do not agree to these conditions, close the web browser immediately and logoff.

 

 

 

 

I recently acquired a wonderful 1992 Loyale Sedan with 4wd 5MT. The body is in great shape and while it has some electrical issues, it is mostly without big problems.

Mostly I say because there is/was a dirty secret in this new Loyale I have named Ash. It has had mice in it! Yes, those filthy little vermin that we only care to see in cartoon form as a kid. They got into the vents and when you hit that heat button you get a face full of mouse pee and  occasionally the bit of nesting material flies out the vent.

Some have torn apart the dash in order to rid themselves of this problem. I thought about that but then thought better. With some well placed dis-assembly and a little bit of chemistry you can both decontaminate and eliminate that urine smell and once again turn on the heater.

The first step is to get rid of what mouse bedding you can find. The reason is that our sense of smell is keenly attuned to that nasty urine odor and the slightest bit of urine soaked bedding will keep you wheezing and gagging every time you turn on that heater or AC.  
 

 

Step One - Remove the Cowling.

 

It is either a snap as shown below or screws. Note how big the slots are in those cowlings. If you were a mouse you'd say "woohoo!".  Vacuum out any bedding you see here.
 

 

 

 

 

 

Below is a pic of where the air comes in on the passenger side.

 

 

 

 

 

Step Two- remove the vent grills.

 

 

The vent grills inside the cabin pivot on two plastic dowels. Using needle nose pliers or a flat screwdriver, gently pry one side until the dowl comes out of its hole. Pull forward slightly and then rotate the vent grill down as if to put air at the ground. Twist out. This is an important step because we want all the nasty crap to blow out if possible, not clog our vents.
 

 

 

 

 

Step Three - Cover The Seats

 

Using plastic sheeting or garbage bags cover your seats. We will be having the bedding material blow out and putting it on the seat isn't any good.

 

 

 

Step Four - Warm Up car

 

Roll down all the windows. Nasty things are about to happen, this likes of which your children should not see. It will give them nightmares and only you should be the one with the nightmares. Put on face masks and gloves. No seriously. Mouse droppings can have the Hanta virus and make you sick.  Start the car and let it warm up but do not turn on the heat or ac yet.

 

 

 

 

Step five - Exorcism

 

From outside the car, while it is running, reach over to the controls and crank the heat and stand back to see what flies out. When the debris stops coming out go back and slide the temp selector up and down vigorously. If more crap comes out, stand back and let it come out. Repeat this process until the bedding material can no longer be made to come out. It may take up to 20 times doing this as the bedding gets caught in the temp adjustment baffling and has to be dislodged. You will know it is empty if you have the blower on full blast and you can slide the temp adjuster up and down rapidly at least 30 times and no more bedding comes out. Be sure to be violent while moving the selector slamming it from one extreme to the other. This causes vibrations that will loosen the bedding.

 

 

 

 

Step Six - Fumigation.

 

So now we got all the bedding material out, but there is still a urine smell because it has soaked into the plastics and any small amount will make us gag. So now we need to neutralize the odor. Sterilizing the ducts is helpful too.  

In order to fumigate, you will need to spray a solution into the duct intakes until it is literally saturated. As a precaution, remove your stereo so it doesn't get ruined.

NOTE: The following procedure is dangerous. Proceed at your own risk.

Get a clean spray bottle. By clean I mean so clean you can drink out of it. We are going to do some chemistry and we can only get the reaction we need if the chemicals are pure.

In that spray bottle, fill it to the top with bleach. Use pure bleach, not a watered down solution. These are desperate measures, remember the mouse pee for the love of God!  

A principle component of mouse pee is ammonia. This is the primary smell we get when we smell urine. Bleach neutralizes the ammonia smell. However it can produce some dangerous fumes such as hydrochloric acid, chloramine vapor and oh yeah hydrazine. In its pure form that stuff can explode.

The quantities here are so small there is little danger of explosion but the chloramine gas can make you sick if you sit there inhaling it. Don't sit there and inhale it. Be like Bill Clinton and don't inhale. Well don't sit in the car either while this is going on.

You can learn more about how bleach and ammonia react by this link:

http://chemistry.about.com/od/toxicchemicals/a/Mixing-Bleach-And-Ammonia.htm



I said this could be dangerous. If this makes you too nervous to continue, you may use vinegar as your fumigating solution.


Now with the car turned off, you want to spray as much of that pure bleach or vinegar (whichever you chose to use) firstly into the intake at the cowling. Then saturate as far back as you can get into the ducts from inside the car. Let them sit for 10 minutes to soak. Stay away from the car during this time. Leave the windows down. Keep kids and pets away.

After 10 minutes, come back to the car, start it and get it up to temperature. Do not sit in it while it is coming to temp. Crank the heat on full blast or the AC as you prefer. Sometimes mouse urine only affects one or thr other, By now you know which is the worst, set it there.

Let the blower run for 10 minutes. The with mask and gloves on,  using the spray bottle with your solution, mist the intake cowling. Not a spritz but a damn good soaking. We want lots of continuous vapor to flow through the vents to disinfect and neutralize that mouse pee. Let the car run with the windows down and blower blasting for at least 10 minutes or more. STAY AWAY during this time. Do this spray and run procedure two more times to completely eliminate the odor. It may be needed a few more times depending upon the infestation. Let the car sit with the windows down for 3 hours or overnight if necessary.

Repeat as needed.

 

NOTE:

 

If you notice a white residue coming out of your vents, it is the dried up bleach solution. Take a damp towel and wipe it up immediately. If left on the dash, it can stain.

 

 

 

 

Wipe up with damp towel.

 

 

Reinstall vent grills.

 

Edited July 21, 2014 by MR_Loyale

[Dee2]

Great write up.  Some photos aren't appearing but we get the idea. 

 

thanks for the humor and tips.

[scoobiedubie]

You failed to describe how to clean out the heat exchanger under the dash.  Mice love that area.

[MR_Loyale]

You failed to describe how to clean out the heat exchanger under the dash.  Mice love that area.

 

You mean the heater core? It is really a combination of cranking the blower to remove debris that is between the core and the vent grills (that is what blows out the vents) or if the debris is before the core, remove the blower motor and go after it that way or maybe from the cowling area if you got a small enough hose to hook to a vacuum. Finally what may be left gets a good dose of bleach and the ammonia smell is neutralized. Thus the thread is about how to get rid of the smell, not how to get all the debris. It is the alternative to radical dash-ectomy. If debris removal is your goal, then you need to look at radical dash dis-assembly if the vacuum doesn't work.  Good luck.

Edited July 21, 2014 by MR_Loyale

[turbosubarubrat]

Put a metal screen or chicken wire over the cowl holes to get rid of them re-entering that area. FYI they probably have been through the whole car if they have a nest in the vents so you have a lot more cleaning to do. They will crawl up in the headliner, air cleaner box in engine compartment, under the carpet, under/on the seats, pretty much the whole interior, through the wiring tunnels and wind shield pillars. Leave a trap out with some peanut butter on it just to make sure there isn't any living in the car still. I finally got rid of the mice in my hatch after having to constantly re-trap 2 traps almost every night for a couple days killed about 7. Luckily i caught onto the outbreak and kept them out of all my other cars by having about 10 traps set on the ground.

[Dee2]

They do nest in the heater, so you'll want to disassemble that and clean it thoroughly.

[idosubaru]

Nice write up and approach, good job!

 

pull out the HVAC motor (very easy) and clean that out.  i've found one nest in there before.

 

an OZONE generation works wonders too if there's smell/contamination that is unreachable/impractical/within materials.  it's the only way to actually remove/neutralize odors. every cleaner/spray/cover up solution is bogus.  rent one from places that rent tools (mowers, lifts, back hoe's, etc), they always have them.  hotels have them too as they work for smoke as well.

 

 

 They will crawl up in the headliner, air cleaner box in engine compartment, under the carpet, under/on the seats, pretty much the whole interior, through the wiring tunnels and wind shield pillars.

 

you have a serious mouse problem!

[Hsoj]

Dee is right. The a/c box is their favorite. Its a pain in the rump roast but you will find the rest of their nest most likely in there.

[Michelle McCallister]

There is only one thing I use anymore for pee smells. Gotta try it. Miracle worker. Seriously. Freshana

[Tsuru]

Just Acquired my third Subaru (1986 GL 10 Wagon 1.8 5spd DR) and for the THIRD TIME there is a mouse nest in the heaterbox...

Seems weird that there is this ongoing and continual issue with mice nesting there. It is like it's a genetic thing along with flying south for the winter, swimming upstream to spawn, and nesting in Subaru heater boxes.

 

Laughingly,

Timothy

[ihscout54]

https://en.m.wikipedia.org/wiki/Hantavirus

[Subasaurus]

2 of the subarus ive acquired had nests only ontop of the engine but under the intake and wires chewed through and cut in half but never pee smell or an actual living/dead animal body anywhere to be found on the vehicle.. although the cars were sitting for 9-15years so perhaps after many years the pee smell dissapears?

[DaveT]

My 87 I removed the entire dash, cleaned the whole hvac system with bleach, etc. Put 1/4" hardware cloth in the ports where the plastic ducting meets the body. Chicken wire is not small enough to stop them.

[scoobiedubie]

I replaced my heater core after failing to be able to clean it in place.

[ccrinc]

A blow torch is faster.  And more fun.

 

Just sayin'...

[soopsoop]

could have an unfixed tom cat piss in the air intake,that will keep the mice out. it worked for my neighbor in his pickup. he had no mice problems after that and no more tom cats.

Edited August 15, 2015 by soopsoop

[turbosubarubrat]

My 87 I removed the entire dash, cleaned the whole hvac system with bleach, etc. Put 1/4" hardware cloth in the ports where the plastic ducting meets the body. Chicken wire is not small enough to stop them.

Depends on what kind you buy. Since my 85 brat is apart i'm going to use welding rod and heat it together with my torch. Then i'm going to tack it in with my mig so the problem is gone for good.

[MR_Loyale]

could have an unfixed tom cat piss in the air intake,that will keep the mice out. it worked for my neighbor in his pickup. he had no mice problems after that and no more tom cats.

 

And exactly how does one persuade a Tom cat to do his business in the intake? Sometimes it can be a chore to get the cat trained to hit the litter box.

[jono]

just had this vision of a field mouse cocking his leg against the inside of your air ducts

[jono]

could have an unfixed tom cat piss in the air intake,that will keep the mice out. it worked for my neighbor in his pickup. he had no mice problems after that and no more tom cats.

 

oh, and Tom cat (unfixed) pee smells better than mice pee ??

[coxy]

Ha Ha reminds me of the time the Apprentice when I was working in the Country had to service a Farm Quad that did not run, Boy was he surprised when a very Pissed off Cat leapt out of the Air-box when he took the cover off.

 

We rang the farmer and asked if they were missing a cat and they were so I guess that is one way to keep the little bastards away, I have spent too many hours repairing wiring harnesses after they eat the insulation off the wires.

 

Of course another option would be to keep a Snake in your Subaru that should fix em might also keep thieves away though not guaranteed seeing as I had another customer complaining some bastard stole his snake out of his Ford utility (Pickup)  which was kept in there for exactly anti theft measures, Still has the utility but the Diamond Python is long gone and was never seen again.