My 1978 Starfire, I've had it a year now, only really driven it in warm weather. The car is stock. The temperature gauge has consistently shown 195 to 200 degrees when the car warms up. Yesterday, it was about 30 degrees out, I took it on a 40 minute drive. The temperature gauge stayed down just above 100 degrees for the whole trip (mostly 35 to 45 mph, surface streets with traffic lights). The heater would blow warm air, but not hot air. Is this how the temperature gauge and heating system would act if there was no thermostat in the cooling system? Or is my temp switch shot and something wrong with the heating system? (I know, I could take off the housing and look for the thermostat, but the car is currently not accessible). I am hoping for an easy fix on this one.

 

My guess would match yours, that the stat is missing, or stuck open.

 

X2 on what Randy said. Replace with a good Stant superstat with your recommended heat rating, I'm going to assume a 195. You can get one at your local parts store with a quality gasket.

 

I agree with the others about checking the thermostat. It may have been removed due to overheating in the warm weather. If it's there, it may be stuck in the open position. I don't have the 1978 specs. The 1976 Olds service manual says that most V-8 engines used a 195 degree thermostat, but the Omega 350 and the Starfire used a 190 degree one. Any working thermostat will probably be an improvement for cold weather operation. You can check the thermostat's operation by suspending it in some water on your stove. Use a known accurate thermometer and heat the water while watching the temperature and action of the thermostat. It should start to open around 190 and be completely open by 212 when the water boils. Thermostat repair should be a relatively easy job, assuming that all is done correctly.

 

Just keep in mind that thermostats are sometimes removed in an effort to address other problems (such as a clogged radiator, weak fan clutch, etc).

 

Thanks for the help guys. Next chance I get I'll pull the thermostat cover and see what is what. The radiator is good, I just had it recored earlier this summer (I know, I should have replaced the thermostat at that time, didn't realize there was an issue).