2000 Chevy Malibu

The water pump/gasket on your V6 doesn't come into contact with any oil passages. Nor does your thermostat/housing.

On this particular motor, when coolant gets into the oil, it's usually via the intake gasket, though a blown head gasket is a possibility.

The best thing to do is rent a cooling system pressure tester and check it out. Also, a compression checker will tell you if you have a blown head gasket.

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