I own a 1996 Camry LE, it’s a 4 cylinder with about 190K miles on it. I few months ago, I replaced the radiator which had it running smoothly. It’s recently been giving some more overheating problems. On Saturday, it overheated to the H, and I noticed a large hole in the upper radiator hose so I went ahead and replaced that. Initially I thought that would fix it, as my temperature gauge was sitting in the middle. But driving to work in rush hour traffic it began overheating again. So I pulled over and didn’t notice anything visibly wrong with it; I had enough coolant, my fans were working, I didn’t see any new holes or steam, and both radiator hoses were hot. I started driving again when traffic cleared up and didn’t have any problems. It only overheats when I’m in traffic or at red lights after I've been driving for about 15 minutes. I haven’t had a chance to replace my thermostat, but I honestly don’t think that’s the problem. Any ideas?

 

Did you reconnect the radiator fan and coolant temp sensor switch (located at bottom of radiator) wiring harness plugs after the radiator change?

The fans are linked the temp sensor switch. If coolant temp goes above 199F the fans will turn on. Make sure fans are working.

A test of the fan system is to find the switch, then disconnect the plug. When ign switch on the fans should run when the plug is disconnected. This test does not test the coolant temp sensor switch only the fan system.

The fans should also run when the A/C compressor turns on.

 

Yeah, I definitely reconnected the cooling temp switch (I remember it being a real pain to get back in correctly). And when I pulled over and looked at my car, the fans were spinning at normal speed (my car was also not overheated at this point).

 

Did you flush the engine and heater core with a garden hose when changing the radiator?

If you turn on the heater full blast does this help lower the temp?

Test the T-stat. Place in heating water, should open at 176-183F and be open 0.31 inch at 203F. Make sure the hole or giggle pin the flange is oriented up.

Any sign of boil over (coolant leakage) at radiator cap?

 

a. I did not flush the engine and heater core when I changed it.
b. Turning on the heater does stop it from overheating.
c. I'm planning on checking the thermostat tomorrow
d. There is no sign of leakage anywhere.

 

AHH, new symptom! The air conditioning isn't working. It's not blowing at all (maybe a tinnnnnnyyyy bit on my feet, but I may be imagining that).