Ok guys! got one for ya.
i am not a beginner when it comes to engines, however i am stumped.

1988 Camry 3SFE, 4cylinder, 156k miles

Car only overheats when a/c is turned on.
when i turn a/c on it spikes to above red line within 5 min (highway)
when i turn a/c off it will return to normal temp within 2 min. (highway)

I replaced t-stat (w/ 180f)
Replaced Radiator fan Switch
and replaced Water Temp Sensor
Drained/Flushed/Fill Radiator with professional cleaner and water
When car gets to opearting temp, you can feel coolant moving, so water pump does work. Radiator Cap is new and at 13lbs. The radiator fans do work. All fuses are good and/or replaced

will a/c compressor overheat and raise temp?
Is it a dummy sensor?

Without a/c car temp runs fine. (and in winter)
Im familiar with engine coolant systems and fixing them, just not diagnosing them.

thanks for your help

 

When you turn on the A/C how's the idle? Do you have any long steep up hills to test cooling system without A/C on? Rad may be marginal even with flush. Original rad? Check cooling fins to see how many have detached from the water jackets. It's hard to believe the compressor would produce that much drag to overheat a properly operating cooling system unless the compressor is starting to seize, which should be noticable. You could try jumping the compressor clutch with engine off, A/C belt off and A/C off, then seeing if you can turn the compressor by hand to test drag. If this is original rad then it doesn't owe you anything, and I would replace.

 

idle sounds fine.... i mean you can hear a difference, but it doesnt alarm me. i bet your right with the orginal rad because it is.... i figured with positive flushing results that it was good to go, but probably not. thanx