ok.. i may be retarted.. jus put the engine in, fresh rebuild with forged internals, new water pump, oil pump all the goodies..im runnin a aluminum radiator and 2 pusher fans..my initial start up was perfect.. ran, idled @ 1k for bout 10 mins, EGT ~8k, vac -18, fuel 48psi oil pres 70 down to 24.. then i drained oil (and refilled) and started her again... let run for bout 5-7 mins, and i hear HISSSSSSSS... so i killl the engine.. and notice my coolant temps pretty fucking hot...

engine was @ 1k, -17in Hg, ~8K egt, 30psi oil and 48 fuel. i had filled the coolant res tank, and then used the rest of the 1 gallon 50/50 in the water neck...the his was coming from the heater hosed behind the block that go into the heater core.. the hose on the pass side was extremely hot (and the one that hisses) the driver side hose was not hot at all.... am i stoopid and did not put enuf coolant in?

You probably have a huge air bubble in there. Take the radiator cap off, pour coolant in, until it is full. Start the car, and watch for air bubbles coming out. When the coolant level goes down, add more. Keep doing this until there are no more air bubbles. Good luck.

Yeah, burping could well be your problem. A side note, often if you just squeeze the lower and upper rad hoses, you can get a lot of the air to find it's way to the water outlet.

yep burp the system

Originally posted by adamzty
You probably have a huge air bubble in there. Take the radiator cap off, pour coolant in, until it is full. Start the car, and watch for air bubbles coming out. When the coolant level goes down, add more. Keep doing this until there are no more air bubbles. Good luck.

This is the best way.