[JSatre]

Yesterday I was checking the oil and noticed a residue on the oil filler cap and inside the tube that looked like antifreeze. The antifreeze level was also low on the overflow can so I filled it back up. Any ideas on how its getting in there? There are no noticeable external leaks and the oil on the dipstick looks clean. Somebody told me it could be synthetic oil residue, but it looks too green to me. The truck runs and starts fine. Any guesses?
John