I recently changed my engine on a jdm integra B16A to B16A (replaced faulty motor) . Everytime I run the car hard I lose about a quart and a half of coolant.At High Revs The temperature guage goes up past half (3 quarter way) , shortly after it falls back to normal.the mechanics said they've pressure tested the engine's cooling system and found no leaks .i've since had the cylinder head gasket changed .The same thing happens.The water pump works fine but I can't seem to figure out the cause of this weird problem. Can someone please help???

JOe

 

take out the thermostat.

 

where is the lost coolant going? is the motor smoking white at full throttle? have you changed the thermostat or taken off the radiator cap and let it run to make sure the air gets out of the system? and you dont have compression in the cooling system?

is there anything blocking air flow or is the radiator possibly clogged? how do you know the water pump is working correctly and was the ehad machined flat when the gasket was changed?