Corolla KE70 OVERHEATINGG !!!

[Zubazub]

My 1980 Toyota Corolla (KE70) has the standard 4K engine.
Here is a link to the pic of the engine
http://2.bp.blogspot.com/_G8Dg1XGzwd...0/100_1956.JPG (Just a reference pic)

NOTE: The radiator fan which comes in this model is not automatic but instead is connected via a belt which spins based on how fast the engine is running/revving.

So the problem is that the car overheats with the A/C running. It heats up slowly when the car is moving and heats up quite quickly in traffic jams.
Also with no AC and the engine running, the temperature needle comes up to almost half when the car is not moving. PLUS THE AC'S COMPRESSOR TURNS ON AND OFF ACCORDING TO THERMOSTAT so even this is no reason for the heat up.

I got the following things done to control the overheating:
--A bigger radiator.
--A bigger radiator fan with 7 blades
--An extra electric fan (This is in addition to the AC fan)
--The car is tuned properly
--The engine oil level is perfect and the oil is relatively new
--Got double head gaskets installed.
--Got the radiator completely serviced.

BUT STILL! THE CAR OVERHEATS WITH THE AC ON, IN TRAFFIC JAMS OR WHEN MOVING SLOW..

WHAT SHOULD I DO? HELP

[verlaryder]

The car did not overheat with the AC on when it was new no matter what the traffic conditions.

So the cause of the overheating is likely due to something that has been modified from stock. It sounds like everything under the hood now is aftermarket so you're on your own since no one can begin to guess what the effects of all those mods could be.

[TheGreenMachine]

Just a shot in the dark here, but have you checked your ECT sensor? I beleive these vehicles have a negative type, which means (high voltage=low temp) and (low voltage=high temp). check and see if either your 5V reference could be shorted or your ground wire have low resistance, because that could cause a false reading to your PCM/ECU. do a 1-2-3 quick test using a voltometer, and if your wires are good and the computer registers the voltage highs and lows when you disconnect and then bridge your wires, then you probably need a new sensor.

just a thought anyway

[corolla_nut_83]

You also might try looking into your water pump or possibly your water/coolant ratio is not correct...