A/C - Hot amd whining noise when on

[tuney]

Hi,

I have a '94 V6 Grand Am.
All sounds fine and heater works ok.
When turning the A/C on a whining noise can be heard from the engine compartment and the A/C blows out warm/hot air.
Turning A/C off and the noise stops.

Any ideas as to what the problem is / how much repair costs would be ?
Could it be the A/C compressor ? hope not

[skibum1111]

Turn the ac on and look to see if the compressor is turning or not, look at the end where the clutch is on the compressor. You might need to use a flashlight depending on where your compressor is located. If the compressor is turning, the squealing noise might be the belt, it could be loose or worn. If the compressor is turning and its blowing warm/hot air, its probably low on gas, easy fix. You can get the small cans of refrigerant at most parts stores or walmart, and they sell the hose to go with them as well. Just be careful to attach the hose to the low side of the system. Look for the blue cap, connect the hose to the can, attach the hose to the low side of the system, tap the can, turn the ac on, it will suck the gas out of the can. good luck.

[tuney]

Thanks for the reply.
I checked the compressor / clutch as you suggested, clutch spins ok.
I will get some refrigerant as suggested.

One thing that I did notice, the cooling fan behind the radiator doesn't come on when the A/c is switched on.
Am I correct in thinking that it should ?
Also, after a 20 min drive, admittedly in 85-90 degree weather, I parked the car up for an hour. On my return there was coolant below the car where it had come out from under the cap on the coolant surge tank.
Bad fan / sensor ? Bad cap ? or just a hot day ?

Any more help is greatly apperciated.

[skibum1111]

sounds like a potential for overheating. on my 95 gt the fan turns on when i turn on the ac, but i have the quad4. i would get the situation with the fan worked out before charging and running the ac due to the tremendous amount of heat placed in front of the radiator from the condenser.

[tuney]

Does anyone know what the temp on the the gauge should be when the fan comes on ?
I was going to take the fan out and test it but it doesn't look like it will come out easily with the high end A/C line in the way.
Waiting for it all too cool down and try.

[tuney]

For those people who are looking for the A/C low side service point on a '94 Grand Am GT V6 3.1L...........

I just spent a lengthy amount of time looking for it.

If you look on the compressor there are 2 lines coming off.
It can be clearly seen that one is the high end side, with the red cap, running across the top near the radiator.
The other is the low end side.
As it leaves the compressor it makes a 90 degree angle, drops down a little way and then another 90 degree angle.
The blue low side service port is just after the first 90 degree angle, on the drop down.
This was conviently totally hidden from view by wiring harnesses and was only found by crawling underneath and feeling !!

Hope this helps anyone else looking for the elusive beast !!

[tuney]

Anyone have any ideas as to what could cause warm/hot air blowing out the A/C other than need of refigerant ?

I bought the kit, with a pressure gauge.
Connected it to the low end service port, ran the A/C and the reading on the guage was 30psi with an ambient temp of around 68 degress.
According to the guage and the chart that came with the kit, this is normal not low.

I was looking forward to an easy fix but now I am really cofused !!

Any help would be greatly appreciated.

[skibum1111]

Check your condenser, make sure its free of leaves, bugs, small animals, missing children, etc. (I've seen some strange things on mine...), if thats clear it might be the thermal expansion valve...