86 Camry Overheating Issues

[agm2003]

1986 Camry LE with 2.0 2S-E engine. 210,000 miles.
New Radiator Cap 50/50 coolant mix

Suddenly started Overheating:
When driving to work (5 miles with 6 stops & 35-45 mph) one morning(air temp 75), went approx 4 miles and temp was ok (gauge at Half), but in the next 3/4 mile suddenly went up almost to H. I parked it and walked the rest of the way.

Coming home (temp 95), it did fine (Guage at half). I DID have A/C on on the way home (and both fans were working). After I got home, I noticed both fans were running. I turned A/C OFF and neither fan was running (gauge still hovering around half).

I replaced thermostat (not OEM) with 180 degree. Did fine for 3 days.

Then, Saturday morning going to work--it must have overheated as some coolant was on ground. On the way home ran almost to H --(I was ready to pull over AND had "Heater" blowing hot to vent off some heat). After it cooled I looked and radiator is dry--again some coolant on drive.

Note: New thermostat did NOT have vent hole.

Any ideas what's going on?
Thanks in advance for any help.

[Doctor J]

Locate the fan switch and pull wire from it--the fans will run all the time now.Run the engine until the temperature goes to1/2 of scale and then check the fan switch with OHMmeter .If there is continuity,between the terminal and the engine block, the switch is defective and must be replaced.

[agm2003]

The gauge went to about 3/4 and there was continuity. So I'll get a new switch.

ALSO: I noticed the bottom radiator hose was cold. Does this mean this new thermostat is bad?

[Doctor J]

Did the fans run all the time?
Was the thermostat you use two valve type [looked like washer ot the opposite to the "umbrella" end}
If the gauge went that high with both fans working all the time at high speed there is still inadequate circulation in the system [restricted radiator -unlikely, or lazy thermostat]

[agm2003]

Originally Posted by Doctor J

Did the fans run all the time?
Was the thermostat you use two valve type [looked like washer ot the opposite to the "umbrella" end}
If the gauge went that high with both fans working all the time at high speed there is still inadequate circulation in the system [restricted radiator -unlikely, or lazy thermostat]

I don't remember if it looked like that or not--if it's like a washer on the end a short bolt, no, I don't think it did.

But remember, I tested the fan switch and it gave continuity at 3/4 gauge.

I think I'll check the thermostat while I have the coolant down for a new switch.