I have a problem with my 97 Taurus wagon where the temp guage starts to
climb when I turn the air conditioner on. I checked the fans and they are
on when the air conditioning turns on. When I turn the a/c off, the temp
quickly drops back down to normal operating temperature, even when it is 32
degrees celcius (about 90 fahrenheit) outside.
Does the fact that the engine immediately starts getting hot when I turn on
the air indicate that something is wrong with the compressor?
After I turn the air conditioning off, there is a hissing as if something is
leaking from the left hand side of the engine compartment to the rear of the
compressor. Is this a normal depressurization or could a leak cause the
Coolant level and color is good. Car can idle all day in the heat with no
a/c on and temp does not get above halfway.
the hissing noise you hear is normal...its the pressure equalizing in
the a/c system..... when its running the compressor is sucking the freon
out of the system and that how you get cold... when you turn it off then
there is no more sucking on this freon so both the pressure and suction
side equalize and the hissing is what you hear... this happens with all
a/c unit... the reason why your engine heats up with the a/c unit on
is that it is working much harder with the a/c on....
This I know. I guess what I was trying to say was: If the engine stays cool
without the a/c on and USED to stay cool with the a/c on, would the fact
that it now does not maintain a normal temp with the a/c on mean that it is
working even harder than it should? That is - the compressor is screwed up
or something and is harder to turn than it should be... I don't know. I
guess I will wash out the fins like another poster suggested and see if that
It indicates a marginal radiator. The radiator is getting plugged up -
inside, outside, or both. Since the A/C condensor sits ahead of the
radiator in the airstream, it heats up the air before the radiator ever
gets it, and the radiator is no longer able to cool adequately.
Use a hose to clean both the compressor and the radiator. That may be
enough. Look inside the radiator and see if the the water passages are
getting choked off by deposits. If so, it's time for radiator service,
which usually means rodding it out.
If you've got any where near 100K miles on the car with the original radiator,
it's probably getting plugged up inside from corrosion. If you've never
changed the coolant, it could be significantly less miles.
Bottom line is that the radiator isn't doing the job either due to capacity
(corroded fins), or some other external blockage in front of the radiator
(leaves or bugs). The most likely is that the radiator has lived it's life.
Oh - just to make your day, keep in mind that your heater core is just a small
radiator, sharing the same cooling system, and it will wear almost exactly as
long as your radiator. If you notice that the heat isn't as good as it used
to be come winter time - this is why.
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