MyE28.com DEV

I'm going to make a long story as short as possible here.  During a period when I wasn't driving my 535is very much, rodents got into the air intake for the HVAC system and left piles of seeds, acorn shells and miscellaneous nesting material in the plenum under the dash and on top of the heater core.  I  was able to clean out all that nasty debris by removing the blower assembly and the grill on top of the dash, so I thought all was good -- until I turned the heater on for the first time and smelled the awful, unforgettable stink of mouse piss.  

I guess urine must have leaked down through the heater core and into the heater box.  Yuck.  I've tried shooting various sprays and deodorizers in there to eliminate the smell; they helped some, but the stink isn't completely gone.  I'm afraid the heater box still needs to be scrubbed out, but I really don't want to go through the labor involved in pulling and disassembling it.  Is there another way to access the inside of the box besides the hole in the firewall where blower sits?  I read somewhere that the AC evaporator can be pulled out from the side, but I don't see an obvious access point.  Any wisdom appreciated!

I had the same situation. Tried industrial deodorizer sprayed into the hvac fan and all vents while running, an ozone generator, and gallons of other cleaners. Nothing worked.

I ended up pulling the hvac box, heater core, and all ducting. I disassembled and cleaned all parts with the deodorizer and replaced all soft deals, and the heater core. Unfortunately, they are attracted to the heater core and defile them.

Evan after the r&r, I still got a whiff of the vile rodent smell if the car sat for a while. Luckily, it has finally cleared. I also pulled the interior and cleaned carpet with the same deodorizer which I think helped.  

Best of luck.

Well, that's discouraging.  I don't think I need to clean the carpet or upholstery, but pulling the heater box is a major pain, not least because of needing to evacuate the AC system.  I don't drive this car in winter (deep snow here), so I may just try letting it air out until spring and see if it's better.

Have you tried Nature's Miracle ?

No what is it?

You get it at the pet store.  It's for cleaning up dog & cat pee/poo/barf.  Natural enzyme that just neutralizes.  I've used it around to clean up mouse nests too or when they defecate after getting killed in a trap and left a mess.  Mice got in my cousins Mini Cooper, luckily a cabin filter blocked them from getting fully into the car, but they made a nest for the winter.  Put a towel on the floor, some latex gloves, and sprayed that stuff up in there until it ran clear.