Coolant in oil

2000 4.0 with 140K.

I do oil analysis every few oil changes, and the latest one came up with coolant in the oil.

I'm thinking head gasket, even though the 4.0 isn't known for needing them often.

Any other possibilities or suggestions before I dive in?

Sounds like a head gasket to me. Probably just faint steam now but it will get worse. Give the head a milling too to be on the safe side of the repair.

Sorry fred, but unless you've got an aftermarket oil cooler radiator or a cracked block (I certainly hope not) then I cant come up with any other reason coolant would be mixing into the oil. I don't know what they cost in your area, but I know there's a coolant test that can be done to confirm combustion gasses in the coolant. Might be worth the effort for confirmation's sake.