Regal GS AC problems

[Guest TurboSedan]

my AC is still not working in my Regal GS. a few days ago Dan and i tried putting one of those AC fill kits on but the gauge was reading really high pressure and cautioned not to attempt to fill (so we didn't of course). i can hear the compressor kick on/off, and one of the underhood AC lines is slightly cool (but not COLD).

 

another problem i've had is that the driver's side and passenger side were different temperatures. passenger side was stuck on heat, while driver's side would only be warm or hot. so today i pulled both passenger side and driver's side door actuators out and they were obviously broken - both of them had broken plastic gears inside. after i removed them i manually moved the doors to close off the heat. i was really hoping this was the problem - that maybe the hot air coming in (due to the stuck actuators) was simply heating up any cold air from the AC. well, that wasn't the case. thankfully i don't have HOT air blowing on me anymore, but i still have no COLD air

 

anyone here familiar with AC systems? why would the pressure be so high? i might just have to take this car to the GM dealership....

[TheEddie]

I just overhauld my A/C on my Monte so I'm a little familiar..my car was reading really high pressures(on the high side) and my low side was fluctuating at incorrect levels, I drained/vacuumed the lines, put in a new orifice tube( a $2 part can make a HUGE difference), picked up a low mile compressor, oiled the compressor, put it all back together, filled it back up with the appropriate 32? oz of straight r-134-a and voula, ICE COLD!

 

Turns out there was a bad valve on my old compressor, you could hear it releasing pressure when you put your fingers over the compressor holes and spun it...and the orifice tube was cashed because of the bad valve+metal shavings/gunk from the compressor.

 

Just because you hear the compressor doesnt mean its working properly, and a little air in the lines can cause the really high pressures also..as well as a malfunctioning compressor or a clogged orifice tube..

 

The cool (but not COLD) line makes me think your compressor is messed up because thats the same thing mine would do, and my air would be slightly cooler than the outside temp but not enough to make any difference at all.

 

If you take it to your GM dealer its gonna be upwards of a $300-$400 job easy...Everything included I spent less than $100 bucks..all I had to borrow was a vacuum to drain everything.

 

Hopefully this helps?

[Guest TurboSedan]

thanks! the problem i'm having sounds just like what happened to yours. i noticed tonight that the vents seemed slightly cooler than outside temp (with AC on), but it could have been my imagination.

 

how can i find out for sure if the compressor is bad? i would hate to spend money on it and find out it's actually something else. where is the orifice tube located and is that hard to replace? is there some kind of kit i can buy to vacuum out the lines myself?

 

i've never worked on AC before so i'm not familiar with this stuff at all. thanks again

[birdman]

ill tell you what i know. the pressure reading will be very high when the compressor is not on, once you get it to kick on and stay on it will drop alot. you can alawys get the red dye or flourecent (sp?) dye cans and add them, then check where its leaking. thats what ima have to do, mine works for like two weeks then gets warm.

[Bossman429]

The orifice tube should be located in the line between the accumulator/reciever drier (shiney canister looking thing) and the Evaporator core, it is located in the inlet to the evaporator ala this:

 

If the high side pressure is overly high it can indicate a number of things

A clog in the condensor, or condensor not cooling enough, which can be related to the a/c cooling fan not coming on, or not moving enough air.

 

You might try replacing the orifice tube and flush the system while it's apart. You can buy an a/c flush solvent at a parts store like Carquest. I can't remember how it works, but I'm sure there are instuctions on the can.

 

VERY helpful:

http://www.familycar.com/ac1.htm

[Guest TurboSedan]

thank you, that's very helpful! i think i'll try replacing the orifice tube and flushing it out. an orifice tube should be available at NAPA or the GM dealership right? i'll have to see what's available on Monday.

[Bossman429]

You can get an orifice tube at any parts store, should be less than $5.

[TheEddie]

ha, looks like you found some help!

[Mach 5]

just make sure you fully flush the system of R12 and replace with R-134. With both in there, it will clog the system.

[Bossman429]

A 98 Regal will not be r-12, only r-134a after ~1994

[Mach 5]

I didn't realize it was a 98'.

[99RegalGS]

Josh, I would take it to a shop and have an A/C performance test done. IIRC around here they are charging $40 for that. They might tell you what's wrong. In that case you can just fix what they said the problem was. If they don't say what the problem is you can ask them (or look on the RO if they wrote it down) what the high and low side pressure were. Having the high and low side pressures REALLY helps when diagnosing an A/C system.

 

If you don't want to take it to a shop I reccomend buying a gauge set. I've seen them go pretty cheap. If you get the gauges you can tell us what the gauges say and do. Then it'll be alot easier to help you fix the car.

 

I suggest both of these options before opening the system.

[GnatGoSplat]

If your low side pressure is too high, it can also be the control valve.

They are super easy to replace, but the system has to be empty.

 

I had a compressor where the low side pressure was 100psi with the clutch engaged. It was blowing warm air at idle and slightly cool at highway speeds. It was only blowing cold air when the ambient temps were 60-degrees or less. Turns out the problem was a bad control valve.

 

I bought a new one, only to have the compressor bearing go out 4-months later. Completely unrelated, but I guess I should have just replaced the compressor rather than just the control valve!

 

[Guest TurboSedan]

i think mine was around 150psi....maybe Dan can varify since he's actually the one that tested it. we had the engine running and the AC was on while we checked. going by the pic David posted, i believe it was the low side port but i'm not sure. it was the port on the top middle of the firewall anyway.

 

i'm probably just going to go have it diagnosed tomarrow like Sean suggested, and hopefully then i'll know for sure what's wrong and can fix it myself.