This may be a bit long so please be patient with me. Just about a week and a half ago I noticed that my coolant temp guage in the digital cluster was reading fine and my analog one was way off. I took it to a mechanic that I know he said that it was the sensor but to go ahead and change the thermostat and flush the system since the coolant looked a bit old. I drove after and noticed coolant loss. I kept my eye on the colant level for a few days. It did get too hot, just shy of 250. I thought I may have developed a bad head gasket. There was no water in oil or oil in water. When I reved the engine and quickly let off the throttle with the radiator cap off it did not geyser so I felt the head gasket was fine. Engine ran as great as ever. I finally noticed the water pump leaking a bit at idle. That was the source of the magically disappearing Yesterday I changed it and the Opti since I was that far in. I could not get 4 gallons in the system at all even after running it to where the thermostat opened up. I tried to bleed the air out. I filled it until coolant came out of the bleeder then closed the bleeder, ran the car for a couple of minutes, shut it off and opened the bleeder again. I did this several times until only coolant came out. It never even reached 200 dergrees the whole time doing this. I took it for a drive and it seemed great for the first ten or fuiften minutes. Now the mystery issue. It started getting hot, around 238-240. Then all of a sudden the low coolant light would come on the the car would rapidly cool off to around 210-215 and be fine. Ten minuted later the same thing happened. I drove home, let it cool and checked for air again, lots of air. Filled up with coolant, checked half a dozen times, went for a drive with no problem. Today I went a few miles through town to auto zone to get a can of 134a. I had the car running in the parking lot filing it with the 134a and it was getting hot again, hit 241. I got it and started driving home and the low coolant light can on and it cooled of to 212 rapidly. I got home and checked the system, more air. I am frustrated beyond belief with it. Is there a trick to filling the cooling system? Maybe another issue? I also posted wondering the hose routing, perhaps the hoses were put on wrong when the system was cleaned and flushed before the water pump was replaced. Or maybe I screwed up putting the hoses on the pump after I replaced it.

 

Just a thought...is your coolant recovery tank hooked up...and liquid in it?

-Georgec

 

yes. I just figured out that I have a blown head gasket.

 

You have to bleed it with the engine running and at op temp so the stat is open or you will never get all the air out. 92-94 have two bleed screws, 95-96 only one bleeder.
How did you figure out a bad head gasket?

 

Tony, how did you determine that you have a head gasket leak ???? If you do, DO NOT replace gaskets until you determine the SIZE of the leak. Sealants can work wonders if used appropriately.

read my recent post 7 pages.

http://forums.corvetteforum.com/show...ght=read+posts

I posted a suggestion on Alberts thread earlier before i saw your thread.

Joe