If you just changed the oil, how did the old oil look in the drain pan? I once owned a Jeep that always had a milky coating on the oil fill cap. Never had a problem with it for the years I owned it.

Also you could send an oil sample to be tested on your next oil change.

I would do a thorough coolant flush. Be sure the coolant reservoir is totally clean. Fill with proper coolant and keep an eye on it. James