Ok so my car started over heating bad one day and I changed the thermo stat, water pump, then radiator and cooling fans.... I put it all back together and it still overheating..... Something I noticed was when I tried to bleed the system that there was no fluid coming through; in fact whenever it would overheat the main hose to the radiator would collapse. I took it in and was told I had a bad head gasket, so I have been tearing my top down and finally removed my heads and still I see nothing wrong with the gaskets, and I'm sending the heads in tomorrow to get checked and shaved down, I also checked the relays, and they are fine. I did notice on the drivers side head that the sensor attached to it was melted, so I'm going to replace that also. I'm just getting lost and i've done my research and still can’t figure it out. Please help me, anything would be helpful.
Thanks Joshua

 

Could it be my heater core?????? I'm lost??? I also replaced all the hoses and they are conected right.

 

My lt1 overheats bad, does it seem to do it only in traffic or tooling around town when air folw through the radiator is limited? Also, do you a chip or tune?

 

it over heats after being started with in 2 min its in the red and boiling

 

pop off your radiator cap and see if the coolant is recirculating.

 

Well, it's a moot point now, since you're redoing the top end. When you
have that done, and if you still have the same issue, get back to us.

 

well im not exactly re building the moter, im just replacing the head gaskets and having the heads checked

 

Just a minor suggestion. After changing the radiator did you make sure and bleed out all hot air from the system?

 

yeah i tried to bleed the system from both bolts... nothing came out. not even air, so i disconected the water pump and tried to trouble shoot, after reconecting it..still nothing...

 

I had the same problem after swapping rad, and WP. There's a proper coolant fill technique for LT1's, and if you don't do it, you'll get air in the system, and overheat as quickly as you are.

I've heard several different methods... This is what I've done, and it's worked perfectly.

1) Jack the front of the car up, so the rad is higher than the motor
2) top off the rad with water/coolant
3) Open up the bleed screw in the main rad hose a turn or two
4) Start the motor. MONITOR THE TEMP GUAGE.
5) Once the temp guage gets past the 3/4 mark, turn off engine
6) Remove rad cap (be VERY careful, you can get burned here, use lots of rags)
7) Re-fill rad with coolant/water

REPEAT until the system operates normally. You can tighten up the bleed screw if water comes out. It will need to be closed completely after the system is bled of air.

FYI, after my rad/WP swap. I had to do the re-fill about 4-5 times before the system acted normally again.

Good luck!

 

I realize you're not rebuilding the engine, but you're removing the heads/etal, so
it's not important at this point what to diagnose the overheating issue, since you
have the engine apart. Once everything is back together, and you still have the
same issue, you will want to investigate further.