Non Mercedes AC Question. Smells like toxic fumes.

[pj67coll]

I had the AC in my 2000 GMC Sonoma fixed a few months. Back. Replaced literally everything but the evaperator. New Condenser, Recieve dryer, orifice tube and compressor. It's been working great up till today. This morning I had a strange symptom. When I switched on the ac in the parking lot before leaving one of our campuses I heard and felt (Heard from the engine bay, felt thru the steering wheel) a groaning vibration which lasted about three or four seconds. This repeated itself several times during about a 30 second period then it stopped. Immediately there was an overpowering stench that I can only describe as a kind of cross between burning insulation, chemicals, and harbor mudflats at low tide. I guess the last bit wont mean anything to people who have never lived near the sea.

I drove back to the office and apart from the sickening smell the AC performed perfectly.

After a few hours I had to go out to another site and wen I started the car the awful smell happened immediately, though this time no groaning etc. The A/C still worked perfectly and is still Ice cold. But I can hardly drive from the effects of the smell.

Any ideas what could have happened? If the Compressor has developed a leak or some kind of internal seal burst etc could that be the issue? Anyone experienced a similar issue before? Just like some ideas before I call the shop. No sign of anything obviously wrong anywhere in the engine bay, or under the dash for that matter.

- Peter.