On my '99 Camaro, I put another 3.8 engine in about four years ago. Temp. gauge never worked since then until my engine gets so hot that it's about to overheat. Usually when the temp. rose on the gauge it meant time to pull over and cool off. Hasnt gotten hot in a long time but now my temp. gauge works after driving about 50 to 60 miles. Engine is not overheating but still scares me a little bit. Anyone else had this problem?

 

Did you bleed the coolant system? The intake manifold is higher than the radiator on the 4th gens and can get air bubbles in them and the guage will not read correctly. You need to make sure you bleed the system properly.

 

I did bleed the sytem and problem still exists.

 

Are you sure it's hot? Is the radiator hose hard at operating temps? If it's not a faulty sensor, I would start checking things like compression.

 

Sucks they 4th gens are worse then 3rd gens when it comes to heating problems. 2 suggesttions since you have the basics covered. Airdam? Is it still good?? Also check the ac condensor mkae sure its not full of trash. When i got my 4th gen the ac condensor was full of dirt the fins would work just fine unless the ac was on or hwy driving. Cleaned out the fins and ran a comb over for good measure solved the problem.

 

Airdam is good, and there is a little bit of grass in my condenser, but not too extreme.

 

Is your system pressurizing and do you have a coolant bypass?