es3doubleO

I got a 1992 es300, the other day i was driving and all of a sudden my car started to spit out cold air from the heater and the temp. needle went to hot. I thought it was the thermostat so i changed it, but today the same thing happened today, again!

Does anybody have any suggestions as to what this can be??

****YOUR HELP IS MUCH APPRECIATED!****

Pheonix

Quit driving the car immediately before you warp a head & blow a gasket.
Flush the coolant, replace both pressure caps & the thermostat again.
Check that the radiator is not blocked, and that the water pump is supplying coolant pressure.


If you don't change the coolant very often, you will corrode the fins off a water pump, and block a radiator among other things.
And with the engine running, if you bridge OP1 & E1 in the DIANOSTIC's port, the fan should go from low to hurricane. But that's not your problem.


Do not drive that car an inch until you've repaired whatever caused the overheating.

es3doubleO

Thank you very much for your help Pheonix!

es3doubleO

How do i know if the waterpump is supplying enough pressure and How do I test my rad cap?

AdvanSC300

Overheating can also be caused by an air pocket somewhere in the cooling system!!Did you make sure to get the air pockets out after changing the thermostat?

es3doubleO

I started having this problem before I changed the thermostat, I thought it may have been stuck closed or something but i changed it and still having the same problem. I also changed the rad cap but no difference.

I wondering if this could be a headgasket problem, but how would I know for sure??

AdvanSC300

Stuck open would not overheat your car ,but stuck closed would beacuse it would not let the coolant run through the radiator to cool!
I don't think it's the headgasket,I think that something is blocking the coolant flow,try doing a coolant flush to push out any crap that could be blocking the coolant flow!

Pheonix

If it's the head gasket a compression / leakdown test will let you know.

es3doubleO

I noticed it happens after driving for about 45mins to an hour. I get hot air from my vents then all of a sudden it spits out cold air and the car starts overheating.

Pheonix

Probably still a sticking thermostat, the water pump is bad, or there is blockage in the cooler lines / radiator.

At any rate, you do not have eneough coolant flow & you CAN NOT continue to run the engine in this condition. The repair bill, if you can't DIY, is half the value of the car.


(Does the hydraulic fan spin fast when you short OP1 & E1 in the DIAGNOSTIC port with the engine running?)