overheating!!!! HELP!!!!

[tumper93]

LT1's are hard to bleed all the air out unless you can pull a vacuum on the system when it is dry. The way I bleed them before I had the tool was to fill the radiator or surge tank until full, then open the bleeders until coolant comes out, sometimes it won't but the coolant level should drop. Close the bleeders and start the engine then open the bleeder at the water pump and see if any air escapes if only coolant come out, close bleeder, rev the motor to about 2k and even if the temp gets kind of high...say around 240 it will be okay as the bubble should quickly purge. Always seems that it gets kinda warm before it lets go but does do it with RPM up...it won''t if left at an idle.

[69camarokid]

LT1's are hard to bleed all the air out unless you can pull a vacuum on the system when it is dry. The way I bleed them before I had the tool was to fill the radiator or surge tank until full, then open the bleeders until coolant comes out, sometimes it won't but the coolant level should drop. Close the bleeders and start the engine then open the bleeder at the water pump and see if any air escapes if only coolant come out, close bleeder, rev the motor to about 2k and even if the temp gets kind of high...say around 240 it will be okay as the bubble should quickly purge. Always seems that it gets kinda warm before it lets go but does do it with RPM up...it won''t if left at an idle.

tried this, but to no avail. The car still over heats.
dont know what to do. I never had this problem before
Ive heard there is an impellor in the water pump and that if it is lined up incorrectly then it would cause overheating. anyone heard of this or know anything about it?

[tumper93]

The impeller cannot be misaligned, the optispark on older lt1's could though because of how it connected to the gear.

[69camarokid]

The impeller cannot be misaligned, the optispark on older lt1's could though because of how it connected to the gear.

perhaps i misunderstood this, but your saying the impellor is ok, but my opti could be misaligned. what does mis aligning my opti have to do with overheating. wouldnt that just affect spark?

or were you just letting me know so i know that the water pump could not be the problem.

[tumper93]

perhaps i misunderstood this, but your saying the impellor is ok, but my opti could be misaligned. what does mis aligning my opti have to do with overheating. wouldnt that just affect spark?

or were you just letting me know so i know that the water pump could not be the problem.

What pump isn't the problem.

[E.rodz]

try this one super easy trick while the engine is running and the cap open use a shop vac and lightly put over the rad. opening don't seal it up completly just put enough seal to suck the air bubble to the radiator.i think this should work just fine.had this problem with an ls conversion and had the car on jack stands.this trick worked in just a couple of seconds.

[130fe]

Like the others have said, it sounds like an air pocket. Are your fans coming on at the programmed temperature? Do they run all of the time or when they are "supposed" to come on. I never had any luck using the bleeder screws so I just removed them totally. The best way I have found to avoid air pockets in my LT1 is to fill the engine block (with coolant) through the upper hose (the one right below the throttle body on top of the water pump). Just disconnect it from the upper radiator hose barb and then reconnect it to the radiator when the block is full. I fill it through the radiator hose and take my time allowing all of the air to "burp" out as I fill it and then fill the radiator to the top. See if that works for you and post up your results.