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Q: Engine pouring oil into radiator

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My Mazda blew a head gasket, so I had to install a new engine. When I started it up with the new engine in the truck it poured all of the oil out of the engine into the radiator! I tried putting in another new engine and it did the same thing! Help! Do you have any ideas on what’s happening and how to prevent this?

A: The only way this can logically happen is i...

The only way this can logically happen is if an oil line from the engine is being connected to a failed "oil cooler" inside of the radiator. The engine oil is under far greater pressure than the coolant in the radiator, so the "leak" inside the radiator is one-way. Most often, this oil cooler is used by an automatic transmission not the engine. Double check any oil line from the engine being routed to the radiator end tanks. A certified professional from YourMechanic can come to your car's location to inspect the oil leak to verify the problem and advise you on corrections.

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