Trying to track down a heat problem on my buddys 97.

We had to replace the radiator the other night, everything went fine, also replaced the thermo-stat at the same time.

Here is the trouble we are having. Sometimes the heat is burning hot, sometimes luke warm to all the way cold. The car takes forever to get to 180 when sitting in the morning.

When i start the car, i have pressure building up in the upper radiator hose coming from the thermo housing. That should not be correct? I thought pressure would only appear there if and when the stat opens?

I have burped the system, all i get out now is coolant. Do you think we got a faulty thermo-stat? We are changing it tonight, just looking for opinions.

thanks

 

Did you install the correct, long, LT1 type thermostat? You may also have a partial blockage in the heater core that needs to be flushed out.

 

Yes, the thermostat we installed was def longer than a traditional SBC one. I thought about flushing the heater core, but the heat was perfect until the rad broke. So i was thinking my thermostat is hung open.

Well, that pressure there makes me think that anyways.

thanks

 

You still got the old thermostat. Maybe try it out if it was still working.

 

I just posted this on another thread,( just tryen to help) cuz I was fighten this heat thing for a month, I had a guy flush the heater core out 3 times and he traced the lines back and in one of the lines was silcone or a gasket type material ( a chunk) of something as he called it, that flew out of the line, hooked all back up and now car heats up in 5 minutes, with the outside temp being bout 2 below. I just thought typical GM heating system that does not work, but I swear 1st degree burns if I hold my hand to vent!!!! Well maybe not that bad, but it sure is nice to have heat for a change.