Cleaning evaporator

[JHZR2]

this year has been an especially horrible one for pollen. don't know why but it has been really bad in terms of getting all over the cars and really setting off allergies.

91 BMW does not have a cabin air filter, and in the few days since I last drove it quite a bit of pollen as well as silver maple droppings and other things that have accumulated on it. Not much you can do we have lots of very well-established trees and everything is in bloom. can you this morning when I got in the car and started it up. out of the air vents came a substantial amount of dust as well as some leaf litter. I have never observed that to happen before. maybe it has in the past and I just wasn't observant I don't know. Regardless it was a time of stuff and I have to guess that it was all passing through the evaporator given that I had the air conditioner on. if a plume just flew out of the vents there must be a lot more that was in trapped in the evaporator.

It may not be practical to remove the evaporator and strong but are there any decent techniques to try and backflush it or get air to go in reverse to clean it out ? I wonder if jumpering the fan in reverse at high-speed would be a prudent move. The car is 24 years old, retrofitted to 134A and still blows quite nicely and I have a cold temperatures in hot weather. But to see all that junk coming through the vents really bothered me. Does anybody do anything proactive with keeping the vents and evaporator clean?

 

[Pop_Rivit]

I'd try to use a combination of the air gun off the air compressor and the shop vac to get the garbage out of there. I also use a cleaner every spring to clean the (Kool-It or something like that). The Buick had been driven by a smoker a few times in the past, and until I cleaned the HVAC system it still had a bit of smokers stench. The smell is completely gone now.

 

[HerrStig]

Getting to the back of the evap will require some digging.

 

[berniedd]

My 1st Generation CRV also did not come with a cabin air filter, though the same model sold elsewhere in the world did. So I made my own, just a redneck fix using a 3M Air Filtrette sheet snipped to fit over the air intake opening just in front of the glove compartment. I just taped its edges onto the lip of the intake ducting. I change it when the decreased air flow tells me it's time. The disadvantage here is that if I shift the air flow pattern to get air from outside the windshield, my filter gets bypassed. No biggie here, we never run the car with the windows down anyway (for safety and pollution reasons).