I have extremely low oil pressure in my 2002 chevy 2500 duramax. 15 psi warm running at 62 mph and 5 psi or less at a warm idle. I was running down the highway and it sounded like I blew a fan belt so I took my foot off the throttle and the truck just died. Opened the hood and fan belt was still there. The truck has power but it won't even crank over. Can fuel contaminated oil cause the engine to seize? or what could my problem be?