1996 Monte Carlo overheating/air in cooling system

[rodryr1]

Yes, this post is old. However, still Interesting the problem continues as the manufacturers doesn't seem to stop selling pressed steel impellar pumps that do not work. One "other" thing I've found is alot of guys are using Chiltons and Haynes reference material for a guide. Those books reference the "one" bleeding point above the thermostat. Look on the firewall in the area of the brake booster. There is a second bleeding screw on the line running to the heater core (Haynes doesn't mention that one chances are Chiltons likely doesn't either) At least I can tell you that the second bleeding screw is located there on the 96 Monte Carlo z34. This one is the key to filling the system and getting most of the air out when you fill the system. If you don't open that one you will be messing around for awhile bleeding the system of Air. I've been there done that. Also, removing the steel impellar water pump and replacing the pump with the ac delco pump (or a pump with the cast impellar) doesn't solve the problem immediatly something else is happening obviously. Pressure testing the system seldom lies. About the only thing pressure testing doesn't cover is the radiator cap. (unless the kit your using does check caps) I've seen a resevoir line plugged before and that can give you some issues during a refill. This obviously doesn't allow a place for any air to escape during initial warm up or allow the system to pull coolant back into the system during cool down. Not trying to sound elementary here folks. I simply understand your pain. This problem drove me nearly nuts untill I came across the fix.