So I've been having this problem for a while now, and I can't seem to pinpoint why it's doing this. It started before I swapped from the factory radiator and water pump, to ZZPs oversized radiator and a Meziere electric wp. I've got a 180* tstat, and the fans are set to come on at 180, and turn off at 175. I never have a problem with heat until I turn on the AC. As soon as I do, the temp slowly climbs from 180 to 212+. The only way I can run the AC and not reach 190* is on the highway. I have x2 14" mishimoto fans, so I'm pretty confident that's not the issue. I also replaced the AC compressor and charged the system myself, about 6+ months ago, but never had a problem till now. So that leads me to believe it's the condenser, but I'm not quite sure. One thing I did notice though is most cars will basically leak water like a faucet once the AC is on. But my system doesn't seem to. Side note, I do have a head gasket leak tester, but haven't tried it.

 

At what point did you swap the fans?

Just a quick read through that it cools ok on the highway, but not ok at slower speeds makes it sound like it doesn't have enough fan.

 

I swapped the fans at the same time as the pump and radiator. But in case it wasn't clear, this issue started prior to overhauling the coolant system. I was doing some wot pulls one evening with the AC on in between. I would shut it off while I made the pull, then turn it back on. That's when I noticed the coolant temp was 210. I decided to overhaul the coolant system after that. I'm not sure how the 2 14" mishimoto fans couldn't be pulling enough air. They're some stout fans. One thing I noticed though is that they won't stay on after shutdown when the temp is above 180* like the factory fans did. I can change the temperature setting and time they stay on with hptuners. But the mishimoto fans don't do that. They are wired straight into the factory wiring. Meaning I cut the wires for my old factory fans, and wired in he mishimotos. I don't believe I can use a larger gauge wire, because the fans come pre wired.

 

I had overheating problems with my 2006 Pontiac Torrent finally I replaced the head gaskets and all was well.
However up until I did that I messed with a lot of things trying to solve the issue.
But on the Stock system when the AC is on the Fans are on every time.
So maybe something got changed in the wiring that caused the fans to shut off when the AC is on. Might be just the wiring is reversed?

 

I might get around to using that head gasket testing kit I bought then. The wiring on the fans is pretty much impossible to mess up. It's two wires per fan. If the wires are reversed, then the fan spins the opposite direction, so double check your polarity, which I did. The fans spin the correct direction.

 

Yeah, I got that the issue was prior to the pump/radiator, just didn't realize it was before the fans / any replacmements at all.


You mentioned a concern about the condensor - is it clean / free of debris?

 

As much as a 20 year old condenser can be. The bottom maybe 1/4 has some pretty bent fins due to road debris. That was just the only component in the AC system I could see transferring heat to the coolant system. The other being the compressor putting too much load on the engine, but it doesn't sound like it is.