Hello all I am new to this list and thought i'd ask a tough question right off the bat.. I can't get my car to stop overheating. It takes about 15 minutes at idle and it overheats. I replaced the thermostat with a 180 lt1 reverse pop thermostat. I replaced the water pump. Mine wasn't that old but still under warranty so I said the heck with it replace it again. I even put a new radiator in because i noticed a small crack where the hose hooked up on the tank and so I put a new one in. The system is bled all the hoses are on correctly. I even tried running it without the thermostat it just took it longer to overheat (about 20 minutes). I really hope it is not a head gasket. I did check the oil for antifreeze and there is none. There is no steam from the tailpipes. I have noticed this. When I start the car with the cap off the radiator it pushes the antifreeze out like a geyser everytime the motor turns over. When it starts it sucks it down however it always stays right around level with the cap. Is this normal? If so what does this mean? The fans are definetly kicking on because I can see them and hear them and also because I have a manual control fan switch that is working. I am leaving for the air force in 12 days hope i can figure her out. This cooling crap is driving me nuts I am glad my airplane is air cooled.

 

I would do a compression test on the motort to see if indeed a head gasket has a small leak. Also is it boiling over or are you just reading it hot?

 

it's boiling over. I thought maybe the sensors were bad so I replaced both of them (water pump and on the block) and still wasn't those. I even bought an autometer temp gauge thinking maybe my gauge was bad. Not that. I think the compression test is my next deal. I was going to do that but the engine has no misses in so I thought maybe it was alright. But, looks like I'll do it anyway.

 

Just a thought, but this happened to me with my girlfriends car. Are your fans working? If there's no airflow coming over the radiator, it's not going to cool down much. Same thing happened to my gf's car, and while not an F-Body, it did just what yours is doing. You didn't say if it cooled at all when driving continuously.

Check the most obvious before getting into the really technical stuff.

 

is there antifreeze coming out of the line to the heads? it might be possible the return line or lines are blocked going to the heads since most of the heat generated comes from the cylinder heads. look at the top of the radiator where the cap is and see if there is a trickle of antifreeze coming out. If not it's clogged.

 

found in a tech article

While on the subject of thermostats, the LT1 reverse flow system uses a special, long thermostat that works together with the passages in the water pump to provide proper coolant routing. If you use an old SBC (small block Chevy) style thermostat, you run the risk of the system not operating with proper efficiency and it may overheat. Escalating temps can be caused by poor air or coolant flow.

 

~Generally running hot~



Examine system for any of the items mentioned above.
Check for air in the cooling system via the air bleed screws.

Check or replace the radiator cap (especially if you have heard lots of gurgling and overflow into the remote reservoir. The F-body system uses an 18 psi cap.

Check for any obvious leaks. If needed, rent a pressure tester that will allow you to pressurize the system while it is cool. This will allow you to see if it holds pressure and look for any leaks.

 

sorry forgot to mention it does not cool down at all while driving just gets hotter...it is circulating from the return line....i have noticed when i goto start it when the engine is cold and the cap is off the radiator it shoots the antifreeze out of the radiator like a geyser...can't get it to stop for about 5 seconds then it goes down and stays even with the top of the radiator...drives me nuts i'll tell ya

 

those were the same symptoms I had a month ago. My car is just getting back from having a head gasket chance done now. Sorry man.

 

what was the price of your head gasket job? if you don't mind me asking of course...i have gotten two estimates and they were both about 1200 bucks...over 900 for the labor that is going to stink and i am leaving in less than two weeks with the air force grrr

 

Don't be so quick to think it has anything to do with the heads/head gaskets... Why don't you try bleeding the cooling system first?

There is two bleeder valves... One that is directly above the dreded opti, and one about 6 inches towards the passanger side of the car.

Turn the car on, let it run a little to get hot and open the thermostate... Then loosen the first bleeder valve (the one towards the passanger side), I garuntee you that nothing but air comes out at first... This is/ could be why your car is getting hot and staying hot... once fluid comes out, shut that valve.

Stick some sort of towel or something absorbant under the valve that is above the opti. Open that valve, leave it open and let a small amount of fluid bleed out of it. Close that valve and your cooling problem should be solved... If not, then assume heads/head gaskets.

 

Try a radiator/block flush, get some flush stuff from a local auto shop n flush it. As somone above said it might be a clog in one of the lines. Or take the hoses off the radiator and turn your house hose to full blast and flush out the block w/ high pressure. I had no heat in my 89 jeep and couldnt understand why, so I took the hoses off of the block, flushed EVERYTHING out with my hose. Some chunks came out, bits of rust, but when I hooked everything back up, it ran about 30* cooler and my heat worked beautifully.

 

Well if your driving it often and its a small combustion leak into the coolant. it will push coolant out while driving causing low coolant and a hot spot of air in the coolant.

 

Hopefully this was resolved, since the last activity on this thread was 12 year ago.

 

"2fast4u94" has not signed in to the site since 7/6/2003!!!!!