The issue has been going on for a while (smelly air, moisture blowing
into the cabin, etc...) for a few days. This morning, the AC started
to make a clicking sound that went away when I turned it off. I turned
it back on and heard a belt squeal for a few seconds, then the car
Now, the car runs fine as long as I don't turn on the AC. Stalls as
soon as the AC kicks in if I turn it on.
I saw your other post too just now. The smell very well could be mold
growth etc, but you described air restriction and fading cooling
performance and generally what sounded like the evaporator icing up (as
some other folks also already mentioned).
From this, I would suspect the thermostat on the evaporator has failed and
is allowing the system to freeze the evap core. This can quickly steal
enough moisture to block air flow (which would make things worse).
Once this happens, the refrigerant which is supposed to be going back gas
phase is starting to stay more liquid, and that (unfortunately) will cause
your compressor to do the things you're noticing - too hard to turn means
slipping belt and stalling engine. It also may quickly cause your
compressor to fail.
I would check the thermostat switch - they're suppose to open at like 34F
or something. Another cause of misbehavior is if the switch has come free
and isn't sensing the evaporator temp. I've seen them typically strapped
right to the fins.
Good luck, hope your compressor is OK. I wouldn't run it at all until you
can check the switch.
John Smallberries wrote:
2002 Passat's don't use a thermostat switch. On the Passat and most other
newer VW's the clutch is controlled by monitoring the low side pressure and
there's nothing connected to the "fins"! Check your information again. The
pressure switch is really just a "in case" switch since the way the system
is designed the compressor runs 100% of the time, at least here in
Pennsylvania. Maximum air temperature should be in the range of 40-48*. As
to why the engine stalls I would say you had a rare compressor failure.
Under warranty I presume?
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