overheating already

[angeno]

Does it overheat only when the a/c is running?

Yes, this is correct. It only overheats when the A/C is on and usually when the VX is under load, such as after driving on the highway and sitting at a traffic light.

[eternal21]

So you can strike the thermostat, radiator, etc. I'm betting that the issue is w/the a/c compressor/bearing. Working through the same issue myself for the past 2 years. After upgrading everything in the coolant system (Ron Davis all alum racing radiator, thermo, tensioner pulley, Ron Davis dual 12" electric fans in custom shroud) + cutting a huge vent hole in the hood), the problem persists. The only thing I didn't do was the water pump, and others that have this issue *have* done the water pump and it still continues to overheat, so I don't think that is the issue. I've been reading some old posts recently about how others have had a similar issue, and after changing all of these things, still nothing. On a side note, my tensioner pulley shredded itself late last year, and I thought that this might have been the issue, but as 2 weekends ago showed, me, I was wrong *lol*.

Someone in one of the threads I bookmarked on my other computer mentioned the same issue, and the ac compressor being tested and drawing a heavier than normal load on the engine. I'll know more in about a week or so, as I'm going to have my A/C tested in the next couple days, and most likely have the compressor replaced. (Most likely will do the expansion valve and dryer while I'm at it, since the system will be open.) AC compressor is the only thing left that draws on the system when the AC is on. And like you, I could be sitting in 100 degree temp for an hour, and everything is just fine (which rules out heat soaking, too). As *soon* as the a/c comes on, in 5 mins, it wants to overheat. ONLY WHEN THE AC IS TURNED ON.

Interesting that we both have '99 Ebony VXs, too. You, sir, have excellent taste!