From cold start oil pressure goes to 40 pounds. After running for 10-15 minutes slight tapping is heard from passenger side of engine block. Tapping gets louder and oil pressure slowly drops to 10-12 pounds at idle. When engine is revved to 10-12 thousand, pressure climbs to 40 psi. Oil is changed every 3000 miles and quality oil for high mileage vehicle is used. Would think it is a hydraulic lifter problem, but symptoms are backwards. Any ideas?
Tuesday, January 2nd, 2007 AT 9:42 AM