Ok I have a new 160 thermostat, LS1 radiator, radiator fan running 100% all the time. the car is a 92 305 5-speed and I have the air dam and cleaned the ac condensor but still the car will break 220 with the heater on full blast. the temp will go down a little when I rev the engine. The last thing I have to replace is the water pump because everything else is new and I don't have a blown head gasket. Could it be the water pump not flowing enough water or something like that It has been replaced but not by me.

 

Shot in the dark: Older thirdgens (and perhaps the new ones) had a spring in the lower radiator hose to keep it from collapsing.

JamesC

 

The hose isn't colapsing but I was driving it last night and it got up to the fist mark in about 10 min then on the way back it got to 220 and no higher. I am really thinking it might be the thermostat even though it is only like 2 months old because I have enough coolant and the fan and air dam are doing there jobs just the water pump or stat may not be.

 

Problem solved it was the new thermostat I tested it and it wouldn't open a little till about 200 and even then it was barely cracked open. SO got it up to about 300 with a electric heater coil and it was about half way open and it started to change color from being super hot and wouldn't open anymore.