Hi have a 2002 ford explorer v8 4.6 just had motor fully rebuild, and still have coolant mixing with engine oil, please help

[Scott Molloy]

Hi i have a 2002 ford explorer v8 4.6 just rebuild motor, and still have coolant mixing with engine oil, compression test good, radiator leak down test pass any help much appreciated.

 

[96eb96]

How is the oil filter housing? There is a gasket there that could go bad.

 

[Scott Molloy]

oil filter

Hi thats been done

 

[96eb96]

Hi thats been done

If coolant leakdown is good, are you sure it is not ATF/radiator? There is an internal cooler.

 

[Fix4Dirt]

welcome to EF!

 

[JCat]

I had this happen to me once. It was a cracked block. Sometimes the crack is so small that your typical compression and leak down tests do not detect it.

 

[429CJ-3X2]

I had a 302 that was getting oil into the coolant, but not coolant into the oil. My mechanic friend said that indicated a crack in one of the heads that was so small it probably closed when the engine got up to operating temp. I traded the car rather than fix it, so I can't confirm that was the problem.

 

[Scott Molloy]

Hi is there an internal oil cooler inside radiator,

If coolant leakdown is good, are you sure it is not ATF/radiator? There is an internal cooler.

 

[Fix4Dirt]

Hi is there an internal oil cooler inside radiator,

afaik yes there are 2 lines for trans fluid that go to the rad and it cools (or warms in cold temps) the fluid to close to coolant temp.it should be on the driver side of the rad and is 2 metal lines iirc