The reason why there is a mildew smell is that there is mildew growing in
the ventilation system. There's a hole in A/C system where the water that
condenses as the air goes through the A/C system to get cold. The hole is
You need to unclog the hole. How? Stay tuned! I don't know. But someone else
They sell "Non-acid, foaming, self-rinsing" AC evaporator coil
cleaner sprays for air conditioners that will solve this problem - one
popular one is BG Products "Frigi-Fresh" sold to mechanics, there are
other brands that are sold to the Wholesale AC & Appliance Service
trade but it's the same basic stuff.
You have to spray it into the air intake duct right at the front of
the heater box so the foam works in the right place, on the front face
of the evaporator core - the part that gets cold... So a mechanic (or
you if you're brave) will need to know where to drill a little hole in
the heater box or the air duct on the intake side, stick the extension
tube from the cleaner can in the hole and spray in a controlled dose
of the cleaner, then insert a plastic plug in the hole for next time.
Give the cleaner 15-30 minutes to soak into the crud (or follow can
directions), then go take a long drive with the AC on and the dampers
set to "Fresh/Outside Air" to start the rinsing process.
(When set to Outside the air will be more humid and create more
condensation on the core than the Recycle air that's already been
through the AC system a few times and already wrung dry.)
That cleaner should also dissolve and flush away any moldy slime
growing in the bottom of the heater box that can clog the condensate
drain hose - the spot where you're /supposed/ to see the clear
condensate water dripping from under the car when the AC is used.
--<< Bruce >>--
it happened to my 1991 Previa on trip to Florida few yrs ago. Interior
of the van was also flooding :) I crawled under the car and blew
thru that short black hose/drain sticking out off underbody. Lots of
dirty water got drained afterwards. No problems since then.
P.S. Naturally, I felt compelled to rinse my mouth with a decent
amount of (good brand) whiskey after the fix-up. Just for healthy
mouth and general hygene.....
NO!! This is one time where experimenting with home remedies is a
very bad idea.
You have to be Very Careful what chemicals you put in there - the
evaporator core is made of aluminum tubing and fins, and the wrong
chemical will eat a hole right through it and cause a leak. Bleach
and chlorine solutions are very reactive with aluminum.
Then you get to find out what real fun (and expense) is when you
have to change the evaporator core.
--<< Bruce >>--
Relax Bruce, It's ok to use as long as you mix a weak solution and flush
it with water. Some of the commercial stuff like you mentioned is at
times a bit harsher on fins than water and bleach, depending how you mix
it. They work by actually attacking and etching the aluminum, and in
untrained hands can do some real damage as you mentioned. I have used
both, and for cars, as I mentioned, mix a MILD solution. I guess I
forgot to post to not let it remain for a long period of time on the
component, and flush with copious amounts of clean water. My mistake,
sorry. OBTW, if you really want to see some reaction, try cleaning
hardened concrete from aluminum tools using muriatic acid. That is the
type of reaction you don't want on thin aluminum.
I had that problem at one time. Turned out the evaporated was not
draining and it was pouring into my 95 ford escort station wagon
passager sid floor board.
Evey time i would turn on the air......the floor would get wet and the
mildew smell would set in.
All we had to do was fix the evaporater drain tube..you see it only
can out about 1/4 out of the firewall and was pour down and some how
got into the car and as the water set in there it became mildewy.
Maybe that might help you ............. not sure
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