New one on me Oil in coolent

But no coolent in oil
87 4.0 any suggestions on what/where it's coming from?

Transmission fluid due to leak in the cooler in the radiator?

Its either a shot head gasket or your in-radiator cooler(if its ATF). It is NOT unheard of to have one fluid cross contaminating into the other, and not vise versa. Just think of the oil pressure your truck runs. Then the water pressure, is what 16 psi max? Very possible that the gasket leaks when pushed on hard from the oil pressure, but going back the other way the water pressure doesn't have the power to blow back into the oil. There is one other possibility....

Your buddy dumped some oil in your coolant so you freak out. :looney:

old_man said:

Transmission fluid due to leak in the cooler in the radiator?

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I'm thinking you may be correct, any way to be sure?

langer1 said:

I'm thinking you may be correct, any way to be sure?

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check the ATF level, look for coolant in the tranny. Water/coolant will destroy a tranny quick.

Just wanted to post back it was the tranny cooler in my CFS three row.

langer1 said:

Just wanted to post back it was the tranny cooler in my CFS three row.

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Thanks for the follow up.

Did you have it repaired or replaced? Was it under warranty?

I just replaced it with a Performance two row Aluminum 78 PAL, it runs cooler than it did with the Brass three row.