I thought this was such a weird problem that I had to post about it, along with a pic.

Recently, I noticed that when it was cold outside, I would hear a roaring type noise coming from the HVAC fan that would get louder as the fan speed increased. I was hoping that it wasn't a majpr issue, but I was surprised to find out what it actually was.

Apparently, a critter decided to build a little nest in between the fan and the cabin filter. When I pulled the cabin filter cover off to have a look, a bunch of pink insulation fell onto the floor of the car. I reached in with my hand and removed all of it, and the roaring noise went away.

I assume that the nesting material came from my garage walls that the builder insulated and covered with plastic, but never drywalled. Unless this material is used somewhere in the Mini? I am also wondering how the heck a critter got in there in the first place. The cabin filter cover is too tight for anything to get in that way, leaving only the fan side, which seems odd. Also, the material was free of excrement and smell, so whatever did it didn't stick around very long.

 

wow thats crazy. i've heard stories where rats and mice nest in the engine bay. good thing they didn't chew on your wires too.

 

Wow, that is pretty crazy. How big was that nest? Seems pretty large, and dense.

 

It was about 6 inches in diameter and pretty thick and dense. It probably took up the entire area from the filter to the fan. The funny thing is that the car is a daily driver all year round with maybe a weekend of non use here and there, so whatever did it (probably a mouse since our cats catch one every now and then) worked quickly. I can't imagine how much work it would take a single mouse to move that much material.

Another funny thing is that the same garage houses a car that is used only several times during the summer and I've never found a nest in that car. Next weekend, I'll be going through that car very closely.

 

So my son and I were driving the Mini one day and the inside smelled kind of 'stale' with the blower motor on. I figured it was time to replace the cabin air filter and ordered a new one. When I dropped the old filter out, lo and behold a big mouse nest made from chewed filter and scrap paper was sitting on top of the cabin air filter - including a dead baby mouse! Ugh!

I went to work with a shop vac and disinfecting solution on the inside of the airbox. I saw how there is an air intake passageway from behind the battery which was probably the entry point. Is there another intake source that needs to be checked? While the smell has improved I still get a whiff of mouse at times.

 

Did you get the charcoal filter, that may help with the smell.

 

Yes, I used a charcoal filter. Maybe I am overly sensitive or imagining things. The mess really creeped me out.

 

It would creep me out too.

 

Oh my, my nephew in Ca started his engine the other day and hear a screaming cat, horrible experience as I love animals!

 

Hey,
As the OP, I just got notified that this old thread had been replied to. Although the Mini has been gone from my garage for over a year now (needed something bigger, so now drive a Charger Blacktop), I remember seeing that one of the Mini vendors has come out with a screen kit that mounts in the passageway behind the battery. So, I guess this is an issue for several owners.

Good luck with the smell removal. I mentioned the other summer only car I own. Well, I had a huge nest in that car many years ago and removed the HVAC system and gave it a good cleaning. However, the car always smelled - for years. It wasn't until I had to replace the heater core that I found another pink-insulation critter nest. Thankfully, no skeletons, but it smelled really bad!

Eventually, that smell will go away now that all of the material has been removed.

 

Anyone know a source for this? I'm still getting @&#@2^# mice building nests on top of the cabin filter. I've tried using 'Fresh Cab' packets which are supposed to keep rodents away with the balsam smell. They do make the interior smell nice but unfortunately the mice don't seem to mind either.

Anyone else have a solution? Is the large hole right behind the battery the only intake opening that needs to be screened?

 

used to work in a garage years ago. A customer had a noisy, vibrating blower motor. Pulled out the blower only to find him dead with his body sucked halfway though the blower fins from centrifugal force....must have thought it was a hamster wheel. had to remove the whole assembly to clean his guts out. I quit shortly after, lol

 

Here's what I did:

The rubber grommet around the entrance to the fresh air box behind the battery has a deep 'V' channel on the battery side that turns out to be a perfect way to hold in a screen. I went to the hardware store and got some heavy screen / hardware cloth with squares approximately 1/8" in diameter.

1. To make a pattern, I lubed the grommet up with a heavy dose of rubber silicone treatment and pressed a piece of paper on it to get the grommet outlines transferred to the paper.

2. I made a cardboard pattern first. Instead of a single piece, i made top and bottom pieces with about 1" horizontal overlap to make installation into the inside of the grommet easier.

3. After a test fit with cardboard I transferred the patterns to the screen, cut the screens out and installed

4. I passed some small zip ties through the overlap area to stitch the top and bottom screens together. I had to pass these through the battery side, then reach up under the dash and thread them back into the battery side, where I zipped them down tight and cut off the excess.

Let's hope this works!

 

Here's my solution.

 

I noticed that huge opening when I changed my filter earlier this month, I only wish I wore a mask because a whole lot of dust was inhaled. I for the life of me don't get why there wasn't some kind of mesh screen to keep certain things out when designing the car.

 

We had a lot of problems with marten and other annoying rodents. We may not kill, hunt or trap them.An American top product did the job.With his 22 lbs his favorite job is to kill every rodent.Our other cat is hiding behind the barrows.

 

reminds me of an old aviation joke

airline pilots fill out a trouble sheet for any problems that occur on a flight

the mechanics resolve the trouble and complete their piece of the sheet with how they resolved the problem

1 pilot submitted one that said "found mice in cockpit"

the mechanics reply was "installed cat in cockpit"