It might be the computer-its job is to energize the fan relay relay when it senses the correct temperature from the coolant temperature sensor or a coolant temperature gauge sending unit.
Doing a block and pressure tests will help find what's causing it to overheat.
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.
If the block and pressure test passes check the following: , Pressure test the Rad. Cap, Clogged radiator, air lock in the cooling system, Fan clutch, Radiator electrical fan, collaspe hoses, water pump.
November, 11, 2008 AT 11:33 PM
I have had same reoccurring problems with both saturn 1997 sc1 1.9l(i think) sohc, and 2003 l200 2.2l
i'm pretty sure its not anything related to cooling in specific, leaking, radiator, etc.
However I was wondering and asking a question to the Forum Tech- if there were a way to bypass,
i had a friend do it to my 97 saturn where he had the cooling fan engaged as soon as I started the engine and stayed on till I shut it off just like clutch driven