Thread: The weirdest AC problem u ever read

So here is the thing that my AC does.

I start the car, i wait till gets to operation temperature, turn on the AC and it start to freeze me.

I'm driving to work but exactly when i hit the 50mph (almost 80kmh) the compressor stop, its like i turned off the AC.

Once I step off the gas pedal and velocity gets below the 50mph (45, 40) the compressor starts over.

What could it be?

My belts are bit old, they squeak and this weekend i think ill be changing them, would that can help?

My compressor is dying?


Cheers,

Rubén.

i think mine does similiar to the same thing except i have new belts and dont squeak also mine takes a LONG time to cool off in a HOT day.

2 questions: what happens if you go over 50mph, does it kick back on or stay off? (im sure there is a highway near you)
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where do you live?(not that it matters much) do you park your car in the shade or a garage? (when i park my car in the garage my a/c gets alot colder vs. parking the car in direct sun@ +/-90*)
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maybe the compressor builds too much pressure and the pressure switch kicks it off, that would be confirmed by high engine rpms when the compressor kicks off,
or
maybe the expansion valve kicks the compressor off when the "freon" gets too cold,
i think some cars turn the compressor off when the "freon" gets too cold (not sure if our cars are like this),
this is what i pulled off of about.com

"Thermal Expansion Valve: You don't always want to freeze your toes off, so the a/c system has a valve that controls the flow of super-cool refrigerant to the evaporator. This way you can regulate how cold the air blowing on you gets. There are a few types of valves in use these days, but they all do the same thing."

i said "freon" so whatever your using in the car is covered be it r-134a or r-12 or something else
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the seals in my compressor are leaking and im not getting the right pressures (high pressure is not high enough and low is not low enough) my car has a hard time cooling in stop and go traffic but works like a champ on the highway

i somehow think it doesnt have much to do with your compressor

good luck

The pressure switch will keep the compressor from running if the charge is low. You might have just enough to get the system started (really cold air also indicates a low charge) but then have enough of a pressure drop in the system to shut it off as the compressor speeds up with the engine. I would start with a basic check of the charge. Another way to check it would be to drive around below 50 mph for awhile and see if the evaporator coil freezes up. This will show up as a loss of air flow. That also results from a low charge.

answering question 1.

It's stay off, if I run over 50mph, the compressor doesn't start its like driving with the a/c button off.

Answering question 2.

Both, sometimes i park in the garage at home, but at work the sun hit it directly, i'm not saying that doesn't freeze, it just stop working ):

And the pressure thing ( i dont remember what's it name) was reajusted, cuz it was at high pressure (don't know much about AC but that what the guy told me).
Another thing, it doesn't matter if i hit 50mph at 3rd gear or 5th gear, passing over 50mph turns off the compressor.

Contrary to yours, mine freeze equaly at stop lights that driving, so i don't know.





I'm not runinng low o gas, i just recharged the AC system.


Another thing i forgot to post, is that if I turn off the ac with car running, the AC keep working, so instead of having hot fan air i get cold air

in my wife's altima the clutch in the ac compressor is slipping, alot of the time it works at low rpm but when you start accelerating it stops working, also when its cool out or been parked in the shade it works fine, if its parked out in the sun the ac pretty much never works, when it heats up it always slips and wont stay enguaged

ok then you got me, never heard of that problem before, it seems like your a/c works too hard then stops when it wants
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not that it matters, but what happens when it freezes you and you turn the temp knob to hot? does the air actually heat up or stay cold

Most AC units have a clutch in them that either freewheels the pulley or transmits power to the AC unit according to the switch in the interior and some sort of temperature switch that prevents the AC unit itself from freezing to death.

Yours could very well be slipping at certain rpms..
That's my best guess.

Mine is chattering these days. I believe it went long ago.. it's probably metal against metal making that noise, lol.

next week ill take it to try to fix the compressor clutch.

tnx guys!

also, i think is starting to sound like diesel hahaha damm rain!

maybe its overcharged...never hurts to check