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1997 Pontiac Grand Prix SE, 3.8, AC. Blows warm or neutral air in AC mode. Clutch engages on compressor, compressor is spinning, took the compressor off to inspect it but couldn't take it appart cause I didn't have a puller. Feels good though, no junk in the wire screen, can hear it hissing when I turn as though it has compression. Gauges read ~100 on both hi and lo sitting, not running. Running and ac off about the same, AC on low is about 85 hi is about 125. Book says 40 and 340. I put a 2 cans in after reassembly which should be a little over a pound. Couldn't find the expansion/orifice tube, don't know what to look for except I think it is suppose to be a cigar shaped thing. I suspect this is it but wouldn't it have to be blown thru for these pressures on both sides as opposed to being clogged? Any ideas would be appreciated. It's getting hot now days.
Thanks,
Jeff
Answer -
Did you vacuum down the system before you added the partial charge? Not sure of the exact specs on this car but I think it should hold 2.25 lbs. of R134A. A little over a pound is not good enough. What makes you think that there is a problem with the compressor or the oriface tube? The 85 and 125 pressures? The pressures will not even be close to being right if you dont have the proper charge ammount or if you didnt vacuum all of the air and moisture from the system before charging.
I did vacuum down the system using a air compressor vacuum device. The vacuum was down to -20psi, held there for about 10 mins. I read only 5mins needed. Then reloaded with 4 x 12oz cans of DuPont Surva 134a. I put a can on a scale and it was 1 lb. After they were empty they were 1/2 lb. So I figured 4 x .5 lbs = 2 lb refrigerant regardless of that they say 12 oz on the can. As far as the pressures go, by Haynes book shows low side should be 42, high 340. So as I write this, I went out and hooked up the gauges again. Off, both read around 120. On, full on high side stays around 120-130. Low side goes from 120-130 upto over 340 then the condenser fans kick on and drops to 120 and the fans kick off. Then it goes back up to 340 and down again. That appears to be the cycle. I paid $25 for a diagnostic at Pep Boys. They say $520 to replace the compressor, accumulator and oriface tube. They couldn't pin-point the problem. I'm thinking I should buy a oriface tube removal tool and yank it out to see if there is a message in there for me.
AnswerYou dont need a tool to remove the oriface tube.
Are you sure about those pressures? The low side should never go up, and in 25 years as a technician I have never seen the low side go high. The 1st time you asked me about this, the pressures were alot different. Also the vacuum job you did was not good enough. It needs to be pulled down to 30 in.Hg. Not 20 psi! It sounds to me like you and Pep boys are both guessing. If you dont have the proper equipment to test and repair the system, leave it alone! Take it to a qualified shop, like the dealer. They will be able to dianose it properly for you.
P.S. If you decide to replace the compressor and oriface tube yourself, you might want to think twice about it. Because if you dont flush the system completely with a good AC flush machine or the equipment that we have in the dealerships, you will trash the new compressor.
