Well just noticed this in the morning. When Im driving the temp goes to the middle of the guage but when im stopped or the car is barely moving the temp shoots up to almost 260. I just stopped by and picked up a new thermostat but im wondering if it could be anything else. If it were the radiator or waterpump it would overheat immediately right? Well im going outside now to pull things apart im going to also check and see if the fans are coming on. Thanks cz28

 

You need to make sure your fans are working, that sounds like the problem.

 

make sure you have an Lt1 specific thermostat, the standard small block stat is not gonna work.

if the car is sitting still, of course it's temp is gonna rise, there is no air over the radiator, untill the fans kick on.

as stated, make sure your fans are working, check the fuse

 

Make sure there is coolant in the radiator. Also like said earlier check to see if you fans are kicking on. If they are not check the fuses. A bad waterpump can cause your car to overheat but you will know when your waterpump is bad because it will leak coolant from the weep hole. Also make sure you bleed all the air out of the cooling system. Hope this helps.

 

i have the same problem going on too but i have a 180degree thermostat. and its fine when moving so i think its the fans so its time to make a switch