Hello. 

I recently replaced the water pump, hoses and coolant in my 1981 Corvette. I cannot seem to get all the air out of the cooling system. I've run the car with the nose on jacks, and have tried various other methods I've read about in other forums and on youtube. 

The car appears to warm up normally and I can see the temp gauge move when the thermostat open. The top hose gets hot and it all seems good to go. Then I'll got out on the highway and the temp soars up to about 230F.....this never happened in the past. The air temp outside was in the 60s so that isn't a reason for the car to get that hot. 

Any tips on how you've burped your C3 in the past? 

Good Afternoon, I suggest you jack up car on the side the radiator cap is and after you get ONLY that side up with cap off leave cap off..Be sure the engine is cool when doing this.You will leave front end off ground on JACK  Stand on the side of cap,you will leave the car this way for 24 hrs. and check level in radiator after this time period.Fill radiator and allow to stay that way for another 12 -24 hrs...I know it sounds crazy but I have done this every time I have built engines and installed them and followed this procedure.. Assure you it works,if not then you have another problem like a bottom side of radiator loaded with organic solids like Calcium carbonate,Magnesium carbonate and radiator needs cleaning..

If that doesn't work, remove the thermostat and put it in boiling water and see if it opens. I've had bad thermostats when they were new before.

Thank you, I'll try that techniques. 

The radiator is less than five months old..... I replaced it in September. 

I don't see coolant flow through the radiator fins as the fluid comes pouring out after the motor warms up. 

The thermostat is brand new. I didn't have this issue prior to replacing the water pump. 

You're just up the road from me! 

You can test thermostat on the stove and a meat thermometer.Put a sauce pan on a burner as water approches boiling you can visually see thermostat opening and if you have meat thermometer you can identify at what temp thermostat opens.

Also someone suggested to watch water move through radiator with cap off as well,however will not tell you if middle to bottom rows or free and clear.Also for the future do not use house water even if softened water in house as it also has organic solids..

Always use DISTILLED water when adding to reclaim jug etc.or 50/50 antifreeze.   Sal C       nosal1

I've never had to burp a gen I small block chevy.  Once the thermostat opens, it pretty much shoves all the air to the radiator and then out to the expansion tank. Not sure why you don't get flow through the top tubes unless.  Maybe the water pump gasket moved or something.  Maybe take the thermostat out and see what kind of flow you get when you rev the engine.

I would make absolute certain that you have a water pump that is designed to turn in the correct rotation. Wouldn't be the first time a parts place has sold the wrong pump, or a pump was mis-boxed, for the application. Cars with serpentine belts have pumps that spin in the opposite direction from ones with V belt setups.....the pumps will bolt right up, and look the same, but the impeller is different on the two styles. 

|UPDATED|3/2/2019 7:26:38 PM (AZT)|/UPDATED|