zero44

Hey guys I recently had my head gasket replaced on my 93 gs300 and its been driving fine until one day it started to overheat and the heat stopped working.I found out that if i revved it to around 3000 rpms it would blow heat. I figured it was air in the system causing the thermo to stick so i bled it but the problem still occured so i ran it without a thermostat but its still over heating and no heat. What should i check next?

twojayzee

Did you have the heater on while bleeding it ? Have you tried force flushing it ? Blockage perhaps ?

147noob

iTrader: (1)

heater control valve maybe malfunctioning. also check if there is any oil in the coolan or coolant in the oil

zero44

YEah im thinking blockage as well, how can i force flush it?

Coolant is clean and oil is clean, can i bypass the heater control valve?

twojayzee

I have just used a garden hose to pressurize the system thru the radiator cap. Not full pressure, just making sure that water does come back out. You could open the petcock on the bottom.

I wouldnt bypass the heater control valve. Can you hear it move when you go from low temp to high temp on the heater controls in the cabin ?

EDIT: Oh and put a thermostat back in. Its better for the car that way, also a proper mix of coolant for the tempature of climate your in. And a good radiator cap.

Sorry if these seem obvious. Just throwing ideas out there

zero44

All right i got the heat to work, but it just stops working like 10 minutes into driving and the car starts to overheat again.

twojayzee

Sounds like a BHG or still not all the way bled