I’ve got a 1990 Toyota Corolla and I’m having a little trouble with my thermostat. Last week the car overheated and I checked the old thermostat in a pot of boiling water and found that it was stuck. I replaced it and I can’t seem to get the car to work right now. I put it all back together, filled up the car with coolant and then started it up. The car warmed up to normal operating temp but I never could get any heat out of the heater. When it overheated last week, I got plenty of heat out of the heater. Am I putting the thermostat in wrong? The old thermostat had a little jiggle valve or whatever on it, this new one does not. Is that a problem. I’m reading something about the angle these thermostats need to be to go into the car – I can’t figure what angle this should be if it doesn’t have a jiggle valve.
At all of the parts stores, no one has a thermostat with a jiggle valve.
Perhaps there is air in the heater core. You must purge all of the air out of the system after you refill it.
Does this car have a valve in the line to the heater core, of just hoses? If there’s a valve, make sure it’s working.
McP’s guess would be my giess also. Many cars have a purge valve in the line to the heater core. You may want to look at yours.