TexasHonda

I have recently had a problem w/ bad smell (dirty socks, wet diaper bad but not horrible) coming from the evaporator after sitting for a few hours. Particularly noticeable on first start in the morning. This arose after repairs idled the car and was parked outside for 3-4 wks. See my "Timing Belt Fiasco" thread.

I first tried to clean by pulling disinfectants (Lysol and Consan Triple-20) through the fresh air intake. It was obvious that very little was getting to the evaporator since you could barely detect any smell in the air from the vents. As suspected, the attempts had no affect on smell next morning at first start.

I briefly considered discharging the AC and removing the evaporator, however a thorough review of the evaporator removal steps persuaded me that was a mistake. The evaporator is sandwiched inside the climate control module under the dash and must slide out sideways. Lots of items to remove and access is poor. Given the AC performs well otherwise, I decided to look at other chemical injection possibilities. The DWD2 Odor Removal system (see below link) is an option but requires placing a hole in the evaporator case and access to install an injection head. It was unclear how this would work w/ the unusual evaporator arrangement in the TL's. DWD2 Odor Removal

I looked again under the dash and noticed one good thing. The drain hose is readily accessible on the pax side near foot postion on the trans tunnel upset. I decided to try chemical injection via this path. Following are steps I employed:

1) Remove drain hose after allowing system to dry overnight
2) Attach a short length (~4 ft) of clear plastic vinyl tube (~13mm ID). It doesn't fit perfectly but will engage the drain fitting on the evaporator case. Check frequently as it tended to come loose.
3) Suction any retained water w/ wet vacuum from the case.
4) Use an air compressor and siphon injector (picks up liquids w/ a pickup tube to the reservoir and injects them w/ the air stream), inject cleaning solution. I used Simple Green mixed 1:6 w/ water for cleaner. The air injector facilitates blasting the cleaning solution up into the evaporator housing through the clear tube. I did this repeatedly, allowing material to drain out, then reblast w/ air-only over and over. Afterwards, use the wet vac to suction out cleaning fluid. In my case the cleaning returns were slighlty dark but nothing dramatic. Note, I used perhaps 1/2 pint of cleaning solution and other components below. You don't want to inject so much fluid you cause a leak from the evaporator case.
5) Repeat 4) w/ fresh water to flush the Simple Green cleaning solution.
6) Repeat 4) w/ disinfectant (Consan Triple-20). I tested this on aluminum to confirm it is non-corrosive. There may be other chemicals that are better?
7) Allow Consan disinectant to completely dry (per instructions).

I drove car yesterday and mercifully the smell was absent. It's too early to tell if this is a permanent fix, but I'm hopeful. The procedure is pretty simple to implement and I suspect there are others w/ this problem from my search on "evaporator smell".

Any comments, other cleaning or disinectant chemicals, or other approaches appreciated.

Regards