...happens to my Dad's Isuzu Highlander. Walang oil leak (or at least wala kami makita), hindi rin nagbabawas yung oil (and water) at yung takbo nung highlander oks naman, parang walang problem. But everytime we open the radiator cover ang daming oil na nakamix dun sa water. Ano po kaya ang problem? Any recommended talyer na expert on this?

TIA