This week I had my A/C recharged and it actually works. The tech said there were no leaks, at least nothing major so we'll see if the refrigerant holds.

Last night (right around the time I had bought the 1989 XJS) I noticed a "Hiss" or "Tssss" like water dripping onto the exhaust system, when the car was parked.

Ah, I thought. It's simply condensation from the A/C unit dripping normally out a drain, and dropping onto the hot pipes.

So today after driving awhile with the climate control on and hearing the "Tsss.." three times when parked, I drove the car about 15 miles more, not using the A/C or defrost or anything, climate control totally set to OFF. I also checked to ensure the A/C compressor wasn't spinning. It wasn't.

I came back home, fully convinced that I would now not hear this "Tsss" sound when parked.

Wrong! It still did it, at least three times, spaced at several minutes apart.

Funny thing is I can't smell anything associated with it...no coolant smell, no gas fumes, nothing.

Might it be water from the catalytic converter(s) leaking out? Should I be concerned? No spots on the ground....yet.

Thanks again.

 

on a car that old I might venture to guess that the ac drain a partially blocked with crud and holding water inside the case that drips out long after use. Barring pulling the case, pull back the carpets alongside the console, disconnect the rubber tubes and blow air in both ways. You would(or maybe not) be surprised at the crap that is ac cases. Mold, mildew, and other crap that finds it way in

 

Thanks very much. I'll do that.

Reminds me of a Porsche story, an a/c unit case had a maggot colony growing in it. I don't know what they were feeding on but you can imagine the stench. They tore all kind of stuff out before they found it.