Hello and thank you for taking time to read this.... I have a 99' Grand Prix SE with 115,000 miles on it. Recently, whenever I turn the A/C on (within a few minutes of starting the car), a loud whistling/screeching noise (similar to a tea pot) would scare the hell out of me. I've read up on this problem and I think it could be a vacuum leak which causes low freon. Is this true? Several days ago, the A/C went completely dead on the 1,2,3 and 4 settings but works at 5 (only after the car seems to warm up and run for a few). More noticeably, it seems that whenever I have the dial set to 0 or off, and the vent set to any direction (feet,defrost, etc) I will still feel some air coming out. Similar to it being on the (1) one setting. Is the gauge broken, is it low freon? If I run a scan at Advance autoparts will it detect this? Any detailed response with answers or suggestions is greatly appreciated.
-Anthony D.
2007-05-01 03:28:45 · 3 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
It sounds like you have a couple different problems...the whistling noise sounds like a vacuum leak and the fan speeds not working is probably the fan resistor is bad. The resistor is a small plate with 4 or 5 terminals on one side and 4 solid wires with coils on the other side that controls the low fan speeds and is attached to the a/c ductwork under the hood or under the dash. Not sure of the exact placement of it but if you buy a new one at Autozone, they may have a location chart that tells where it's located. Otherwise, a service manual will show you.
The vacuum leak may be harder to track down but I would start under the hood as the engine heat tends to dry out and crack thoses hoses first. Start the car and listen for the whistling and see if you can pinpoint where it's at....sometimes if you pinch the various hoses shut with a pliers to see if the sound stops, you can find the source of it.
If it's not under the hood, the next step would be to check the A/C controls on the dash....sometimes the vacuum lines that run to the selector switch get slightly disconnected and will cause a leak. Otherwise, it's just a matter of getting under the dash to inspect the various hoses for leaks which can be a pain to remove all the under dash components to gain access to the hoses.
Neither of these conditions will CAUSE low freon...that would be another issue but if you're compressor is cycling on and off, it could just be a low charge of freon with a slight leak and the vacuum isuue would tend to not let the cold air blow through your vents properly so it may not be bad at all.
Hope this helps, Paul
2007-05-01 04:14:04 · answer #1 · answered by paul h 7 · 0⤊ 0⤋
Your AC compressor is locking up. Try turning it by hand with the engine off(!!!), you should be able to rotate the center (clutch plate) of the shaft, and should feel some variable resistance on compression stroke. Vacuum leak cannot cause freon leak. Freon leak will disable the AC system all together because there is a low pressure switch that prevents the compressor from engagement. Freon leak may cause whistling sound but will last for a couple of minutes at the most because that's how long it would take to leak out at the rate that would generate noise.
2007-05-01 05:01:01 · answer #2 · answered by Anonymous · 0⤊ 0⤋
you for confident nevertheless have air contained in the traces and this is unquestionably one of your promlems yet bypassing the heater center doesnt help it plenty besides the indisputable fact that it would additionally be a bad head gasket or warped head as this is letting the exhaust into the coolant i purely had to replace the pinnacle and head gasket on my 3.a million cavalier subsequently
2016-10-04 04:51:31 · answer #3 · answered by ? 4 · 0⤊ 0⤋