04 corolla... oil in coolant

[95astroman]

my 04 corolla has oil leaking down the side of the engine and oil in the coolant but no coolant in the engine. could it be a bad oil cooler or a bad head gasket? how do I tell? engine has low mileage since rebuild.

[Brian R.]

I think having an external oil leak and oil in the coolant are two unrelated problems. Finding and fixing the external oil leak should be relatively straightforward.

I would change the oil and flush and then fill the radiator with 60:40 antifreeze:water. See if it happens again.

If you have a cracked, block or head, or a blown head gasket, I would think you would see more problems.

A compression or a leak-down test should let you know if your head gasket is blown. Pull the plugs and see if they look normal.

It might be just radiator stop leak that was put in your engine at rebuild.

Also, check your transmission fluid. It may be transmission fluid and not engine oil. Then the problem is in the radiator heat exchanger and you need a new radiator.