Antifreeze/coolant in Engine oil

1992 Jimmy 4.3L, 4x4, V.I.N –W. 70,000 Miles.

Over the last year I noticed a big cloud of smoke at startup, now I believe its antifreeze combusted through the engine. When I change the oil the under side of the oil cap has water condensation and a bit of green slime/goo. I never really noticed any coolant in the oil, although at times the drained oil looked like it had a drop or two of water.

Coolant does go down a ¼ inch or less every month, which I do top up, and there is a minor coolant leak which I can not find.

Over the pass 6 months I’ve been changing with synthetic at least every month (2000-3000 K) to flush the engine.

Is this indicative of a broken head gasket? Can this be changed with out lifting up the engine?

I may be wrong but I believe this has been on going for the pass 5 or more years.

Should this be looked after right away, or should I keep monitoring the situation to note any changes?

Thanks

This sounds like a internal intake gasket leak. Since your topping it up all the time and have the milk shake under the oil cap, and little puff of smoke at the start, sounds like its getting inside the engine and burning. It could very well be a head gasket leak, but I would in my opinion be looking at the intakes first. Doing a leak down test will give you an idea as to what is going on.