...tell if pump bad or engine bearin? had slight tapping when bought truck but drove great....took to shop other day to get tapping checked was told either rocker arm or pushrod. didn't make it 2 miles before loss of oil pressure started....came on and dropped. oil pressure bounced up and down for 2-3 minutes then nothing. took back to shop were mechanic put 20w oil in to see if any pressure would rise...nothing! does that mean oil pump? or are my bearing bad? do not want to lift motor up to replace oil pump and do for nothing. please help thanks
