A/C causing my LX450 overheat a bit (1 Viewer)

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Dec 13, 2012
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so to the point, A/C radiator gets very very hot! I mean so hot if I spit on it it will sizzle, so this causes hot air to travel to my engine radiator and abnormally heating it causing the car to overheat.
when A/C is OFF everything looking well.
What can cause A/C to be that hot? I do have a new compressor DENSO and new gas r134a correct quantities. any idea why gets so HOT?
 
When you turn the A/c on, it adds a heat load to the cooling system. Your radiator may be able to cool the engine without the A/C on, but it can't handle that extra load. Are you sure the engine isn't overheating even without the A/C on? The factory gauge is notoriously inaccurate.
 
Low refrigerant charge will cause they AC system to get hotter, maybe not that hot though. I also had issues with having the AC on causing overheat in the summer until I replaced my fan clutch with the upgraded blue clutch from Wits End/Landtank. No trouble since then.
 
Mine started doing the same thing this last fall, and it had always run about 10* hotter than what a lot of guys report. My radiator is only a couple years old so it wasn't the issue. I also updated the fan clutch, first modding my original with the higher viscosity oil and then swapping out for the Wit's End blue modded unit. Neither of those made an appreciable difference.

What finally fixed it for me was when I replaced the thermostat. It's the easiest and cheapest fix I tried and since then the truck is cool and consistent. I've never exceeded 186.8* with the new thermostat and the air blows cold.
 
Very very difficult to diagnose until you get exact coolant temp reading either with installed gauge or through the ODB port.
 

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