Hissing Aircondition

AxelBerlin · #1 (**permalink**) 05-12-2006, 05:56 PM

Hi guys,

everytime I´m using the aircondition I have a hissing noise in the driver cabin. It´s hard to locate, it seems like it is comming from everywhere. At first I thought it was the radio because it sounds like a noise from an amplifier in iddle but it´s the AC. The cooling is also not the best, is this maybe a sign of a too low level of AC coolant?

Thanks

Axel

slyalfa · #2 (**permalink**) 05-12-2006, 08:55 PM

I think that is normal? As the liquid changes to a gas. I have a room A/C that makse that same hissing as well as the car A/C. The evaporator in the alfa is very close to the vents if you look in the center vents you can see it. So I think the hissing is noticable do to the locatation.
what does you site glass look like when it is runing full blast?

AxelBerlin · #3 (**permalink**) 05-13-2006, 12:12 PM

Hi,

at the moment I can not check this because the car is till June iin the service for blown head gasket

I will check this asap if I have the car back.
Since the cooling is not realy good and the air is only a littlebit cold I thought that it is a low level sign.

Thanks

Axel

VerdeVeepster · #4 (**permalink**) 05-13-2006, 07:10 PM

The hissing is normal, but if it's not cooling well and the car is running hot then it might need attention. The best way to ensure a long life for your a/c is to use it a lot, even in the winter.

Nipper · #5 (**permalink**) 05-14-2006, 05:01 AM

I was told by a auto electrician, or who ever refills the a/c on cars, that the hissing noise coming from my a/c was due to the gas in my system was a older version, different gas that they used to use. Apparently when the gas starts to get low it makes that hissing noise. My a/c still pumps out plenty of cold air so he said to let it run out before he puts the new gas in. The new gas they use doesn't hiss and is better for the environment or something, I was told.

Todd · #6 (**permalink**) 05-14-2006, 05:12 AM

If you operate your A/C with a low charge (ie not cooling well), your certain to severly damage The system. The Compressor needs cool gas return to remove heat of compression. First to go is the oil which will overheat, and suffer from poor system circulation. It will then circulate nasty acidic oil completely contaminating the system. Then they can really sell you some parts!

Todd
Commercial/ Industrial Hvac/Refrigeration Tech

VerdeVeepster · #7 (**permalink**) 05-14-2006, 09:46 AM

Quote:

Originally Posted by Nipper

I was told by a auto electrician, or who ever refills the a/c on cars, that the hissing noise coming from my a/c was due to the gas in my system was a older version, different gas that they used to use. Apparently when the gas starts to get low it makes that hissing noise. My a/c still pumps out plenty of cold air so he said to let it run out before he puts the new gas in. The new gas they use doesn't hiss and is better for the environment or something, I was told.

Todd · #8 (**permalink**) 05-15-2006, 08:06 PM

The problem with non usage is in the compressor shaft seal. It is a delicate item that uses close tolerances and a thin amount of oil to make the seal. You should use the A/c at least once a month no matter what the outside temp is to keep this seal lubricated and sealing. In very low ambient temps the low pressure switch may keep the Compressor from comming on. In that case with the engine off use your hand to rotate the pulley a bit, or figure out a way to introduce heat into the condenser. You could also run the heater and get the interior really hot, then switch to A/C.
Note that this only applies to open drive style compressors. Your home Compressor is hermeticly sealed.
.

slyalfa · #9 (**permalink**) 05-16-2006, 05:45 AM

The Milano lets you run the heater and the A/C at the same time.
I use this a lot in the winter as this is the best way to defog the windows.