Air was blowing 40 degree until turn off then blowing hot going to town

[p5200]

This is an 05 Pontiac Grand AM GT 3.4L. Vacuumed system down didn't appear to have a leak after sitting under vacuum for an hour. After charging, it was at least blowing between 40-45 degrees so I shut it down. Went to town a couple hours later. It was blowing nothing but hot air and the AC clutch was running. When charging, I heard an extra click like the clutch kicking in. I kept my eyes on the clutch watching it spin and still heard the extra clicks even while it was spinning. Also, after the click high side pressure would go up from about 175 to 225psi the whole time, the clutch stayed engaged. The low side stayed between 25 and 28psi. and the temperature was right at 80 degrees. I haven't done much of this kind of work I sort of don't have much choice at this time. Was wondering about the compressor but like I say, I don't have much experience at this. Hopefully, it's not the compressor! I don't get around like I used to tackling a compressor job would be a rough job for me lol! Thanks for all help!

[p5200]

I also wanted to add there is a rattling noise with compressor running.

[Cusser]

1. Maybe get the system recovered to see if the correct amount of refrigerant was added initially and/or still present.

2. Even though it held vacuum, I wonder if you have a leak.

3. Are the pressure reading you posted measured at about 2000rpm?

[JohnHere]

Right off the bat, it sounds like the refrigerant leaked out, although I can't explain the clutch still being engaged. (Maybe it's stuck "on"?)

Leaks under pressure can happen even though the system holds vacuum.

When you say extra clicks, do they sound like the clutch disengaging and engaging, or a different sound?

What was the ambient temperature when you serviced it? How did you charge it? With what, pure R-134a? How many miles on your Grand Am? Original system and compressor? Has the system ever been serviced, before now?

[p5200]

Test, having trouble replying? Readings were at idle icreasing made very little difference. The low side actually drops when increasing speed. Will see about getting recovered. Whats best for leak testing? Harbor Freight locally, has an electronic tester not sure about their quality though. I've ordered aYellow Jacket Digital refrigerant scale for ounces to 110 lbs. The clicking sounds similar to the clutch but sound but clutch doesn't seem to to be disengaging. I guess it's possible, it could be happening so quickly trying to disengage? After the click, high side goes up from 175 to 225 psi and low side decreases a little. Temps between 50-55 degrees here today crazy weather. Ambient Temperature was 82-83 degrees. Could not find my last post hope this one makes it. Thank You!

[p5200]

It was pure R-134a 156000 miles. Original system and compressor and never serviced except by me replacing factory high side service port that was leaking. I put a Dorman valve with the Schrader valve in it. Pulled a vacuum and charged it 2 years ago just by pressures not weight. My Grandson replaced head gaskets during this past Winter. I wondered if maybe, something got bumped and started leaking?

[JohnHere]

I also wanted to add there is a rattling noise with compressor running.

A rattling noise when the compressor runs usually indicates that the refrigerant charge is "off"—either undercharged or overcharged—and/or something is wrong internally. Since it's the original compressor with ~156,000 miles on the clock, I question the integrity of the compressor.

If you decide to "get into it" yourself, pay particular attention to the oil that you drain out of the compressor. How does it look? Light amber to dark amber are okay. But if the oil is black in color and has metallic particles in it ("glitter"), then the compressor is disintegrating internally and definitely needs replacement.

In addition to replacing the compressor, you'd need to replace the condenser, accumulator, Orifice Tube (OT), and thoroughly solvent-flush the rest.

But before doing all that, one way to judge the compressor's condition is to first remove the OT and inspect it. (The OT will be located somewhere in the liquid hard line close to a joint.) If the OT is clogged with black gunk, sometimes including metallic and/or plastic particles, then you can be sure that the compressor is shot.

As you might know, charging by pressures is guesswork. The *only* way to charge Mobile Vehicle Air Conditioning (MVAC) systems is by weight, which must be exactly as the manufacturer calls for.

The specifications that I have for your car are as follows: 28.0 ounces net weight of R-134a, and 8.0 fluid ounces of PAG-150 oil.

Since you're awaiting an accurate refrigerant scale, the refrigerant charging part will be easy and very accurate. The rest, if needed, is not such an easy job.

Contact Tim at ACKits.com, this Forum's sponsor, for any supplies or parts you might need at the best prices.

[p5200]

That appears to be a lot of good info! Thank You