There are several reasons why the coolant in an engine may become too hot:
you have changed the thermostat, radiator and radiator cap. They should have been tested before any replacement took place. That 's what we call a needle in the dark.
Now let me say this:
-A correctly sealed cooling system will maintain it for 15 minutes to the specified level, and not 3 minutes
Ask your mecanic to check the cylinder head gasket:
tell him to leave the cooling system pressure tester connected the radiator filler neck an apply a low pressure of aproximately 5 psi. Run the engine at idle while observing the gauge.
Execessive pressure buildup indicates combustion chamber pressure are intering the cooling system.
Then you have to change the head gasket.
Saturday, December 9th, 2006 AT 10:18 AM