If its the thermostat it will cause it to overheat. If there's no actual leakage I suspect that coolant is being burn in the combustion chamber due to a blown headgasket you might want the tests below done.
Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.
Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.
Wednesday, December 12th, 2007 AT 4:06 PM