Coollant leaking into oil system?

[Ghost-Flame]

Don't flame me if this has been asked before... I did a search and couldn't find anything.

I think I read here at this forum that a milky condensation on the oil fill cap is a sign that coolant is leaking into the oil.

2 day ago I scrubbed my oil cap with wd-40. I got every trace of crude off of it and today after about 100 miles I have a milky something around the inside of the cap.

Now assuming this car hasn't been with any dirty little Hoes (lol), what would you say is causing this?

The car is an 2002 3.oi with 95,000 miles on it. The engine was abused before I got it @82,000 miles (the old oil from my first change looked like it had never been changed... no kidding it plopped out like liquid pudding) . I have changed the oil 3 times in 13,000 miles
w M1 EF 0w-40 to clean it out. Each time it gets progressivly cleaner looking. this current oil has 3,000 mile on it. I am going to go to 7500 oci. The engine uses about 1 quart in 1800 miles. other wise the car runs great.

what tests should be preformed etc?