Sounds like you have an air pocket in the cooling system.

 

Could be an air pocket, although the flushing should have taken care of that if they did it correctly. Did you have the water pump looked at at the same time? When I experienced a similar problem I had to replace water pump, and distributor system b/c of water leakage onto the cap.

 

Bleeder valves!! When the car has been sitting for a while open the cap. There are two bleeder valves located 5-6 inches from the cap right next to the intake elbow on your throttle body. Open those then start the car. The open vlaves will allow the air to escape. Fill the radiator and let the car run for a few minutes. When fluid begins to come out of the valve then close the valves and make sure you are full then close the cap and you should be good to go. Also check the air dam underneath. If the air dam is blocked or off then this will cause the car to over heat also. I'm assuming the fans work correct? Double check while you're checking the air dam.

 

where exactly is the air dam? I cant seem to find it and I tried looking for the bleeder valves and didn't see anything i'll look again but I'm not sure it has any.

 

The air dam is located beneath the car. Look right behind the front end and you'll see what looks like a spoiler sticking out from the bottom of the car. This handy device scoops air up from the ground and passes it thru the radiator. If you don't see it then it may have came off. If you get under the car you'll see where the air goes into the radiator. It may be blocked. Sorry I don't have pics of the bleeder valves. They are located only a few inces to the right of the cap and you should see them. They are little brass fittings and you'll use a screw driver to open them. Go to shbox.com and you'll see almost everything regarding how to's of you're car. Bleeder valves are #37 on the list. If the t-stat has not been changed in a while you may want to look into that also. Hope this helped.

 

you have to suck them down with a machine somehow:thumbsup:

 

I am having the same troubles with my daughters car. Yesterday she said the temp guage started bouncing around and then it stopped. Temp then held steady around 170-180*. After that the heater won't blow hot air anymore.

Does this sound like a t-stat problem?? Or air bubble?

Sorry to hijack the tread.

I bought a new 180* t-stat today and will change it out tonight then bleed it using the bleeder screws.

Somehow I need to get this thing fixed since it is going to really get cold soon and she is 8 months pregnate.

 

The bleeders tend to work better with the car turned off.

Put a large funnel in the radiator that seals againct the filler neck, so you you can overfill the radiator up into the funnel. Then open the bleeder screws to let them release some air. Close them, then start car for a minute or 2, & repeat process w/ engine off. Then top off radiator, replace cap & then let fully warm up until the system builds some pressure. Then repeat again with engine off.

I've done many LT1 cars & this will give the best results.