Creamy moisture in engine top end - why?

the way I understand it, this moisture collects in the oil filler cap and tube, A combination of short trips, and the vehicle never getting a good long run which helps keep moisture out of the engine. Its unlikely to be just in the filler cap from a head gasket leak, so likely you are right the engine is fine, wipe the moisture out of the filler tube and cap thats pretty much all you can do about it at this point. Although I remember reading something about engines in cadillacs having issues with intake gaskets after 100,000 miles. Check on this website and see www.carcomplaints.com click on search, type in 1999 cadillac catera complaints and recalls ? click searh. on the results page scroll down past the google ads and good luck.