In the last few week ever since i put in my new thermostat 3 times so far my car has over heated, then it would just start running at normal temp agin.

I think my thermo stat is not opening sometimes. But when i take it out it opens when i put it in hot water, but that is always after the car had started to run cool aging.

So is there a way when it is overheating to see if the stat is open or not

I checked the hose on the top of the waterpump when the car overheated ad it was extremly hard( lots of presure in it)

 

Are you sure its a thermo for the LT1 and not a reg small block...

I have had people come to my place of business that had this problem and the parts store sold them the wrong one...

 

well it has only overheated 3 times in the last month and i drive 1000 miles a week, so i am guessing it is the right one, i am thinking it is getting stuck closed sometimes then after i let the car sit for maybe 15min it will start cooling down like normal and stay under 180 deg fo like a week or 2 then it will overheat agin and ill let it set for a while and it will work fine agin, i havnt had the chance to look at the termo when it is overheated yet

 

I have put back in my 180 Deg stock termo to see if it will stop overheating, and it hasnt so far today but i would still like to know what to check when it does overheat

 

This is from shoebox's site. It shows the difference between a SBC thermo and an LT1 thermo.

Thermo


I'd also try opening the bleeder screws and purge the cooling system of any air that may be in there.[

 

If there is air in the system (i know there is now) would it cause me to overheat randomly like stated above

 

If your coolant temp sensor is going bad you can have alot of problems like this also. If that is not functioning right it willnot tell the engine when to cool down.

 

If you overheat in the city, but not the highway then you have a fan related problem (could be fans, wiring, ECT, relays). If you overheat in the city AND the highway, then you have a thermo problem for sure (or something else is clogging up the radiator).

Try changing out coolant and see if that helps because it will clear out most clogs in the radiator.

Your possible problems are thermo, fan relay, wiring, ECT, coolant, air bubbles.

 

Well i know the fans are workig fine, i am thinking thermo,water pump (does it start to go out or does it just stop) or ratyador clog

Ill flush it today and i have already put back in the stock thermo