
Originally Posted by
jick.cejoco
as from the first post, the cylinder head had been removed and serviced, thermostat replaced, thermoswitch replaced, radiator fan replaced, etc. have you checked the engine vacuum at idle? if the engine vacuum is lower than 17 inches of mercury (17-21 inHg for stock camshaft, normally aspirated engine), then there is a leak supplying false air to the engine and making the air fuel mixture lean and raising the combustion temperature. if you see in a scan tool if the oxygen sensor output is pegged lower than 450 millivolts for extended period of time, this is a confirmation that there is a vacuum leak. the vacuum gauge most of the time also tells if the ignition timing is too advanced. both over advanced ignition timing and vacuum leak are causes for engine overheat