View Full Version : Symptom of a Bad A/C Compressor?

08-14-2016, 09:01 PM
Car: 2001 A4 Avant 1.8TQM

Backstory: had to replace the heatercore a few months back which, of course, required emptying the A/C system. Reassembled system when finished, but did not recharge system.

Finally got around to trying to recharge system today. I replaced the receiver/dryer, added the amount of new PAG 46 oil that was in the old unit, and then vacuumed the system out for an hour. System held vacuum perfectly for another hour. Started car, purged service line on a/c manifold, and began drawing in freon from first can. Vacuum in the system drew in roughly 3/4 of the bottle very quickly. High and low side pressure both rose to about 100psi and compressor kicked on as it should. Then nothing...

System refused to draw in the rest of the can. Warmed the can up, held it sideways, upright, upside down, shook it... made no difference.

I verified the compressor clutch is engaging as it should, so the compressor is running.

What's going on here? Bad compressor? Compressor worked fine before the heatercore job.

Also, I neglected to remove and clean the orifice in the high side line at the firewall. Could that be the issue?


08-16-2016, 08:00 AM
whats the low side pressure when the compressor kicks on, are you charging it through the low side port?