5.4 lt No oil pressure with new pump??
I'm new to the site, this is my 1st post.
I'm working on a friends 2000 F150 7700 series 4x4 5.4lt. The truck suddenly lost oil pressure while driving on the highway. The engine was shut down right away and appears to have taken no damage. I verified no oil pressure with an external gauge. This is a high mileage truck, approx 250 000miles (389000km). Upon dissassembly I found that the timing chains and guides were junk. I replaced the oil pump and timing set. I changed the oil and filter and cranked the engine with the starter to prime the pump and verify oil pressure before I put the front cover back on. When I removed the old pump I dissasembled it and found no damage. I even put about 15 inches of vacuum on the oil pressure guage port in an effort to help draw the oil into the pump with no luck. I removed the filter as well and the pump will not pick up the oil. I suspect the pickup tube is cracked, although I haven't been able to verify this as I changed the pump without removing the oil pan. As the engine lost oil pressure suddenly on the road I never suspected a broken pick up tube. I should add that when I changed the pump I cleaned out the inside of the tube and verified there was no blockage with compressed air.
Has anyone ever experienced this before? Does the starter motor spin the engine fast enough to prime this type of pump (gerotor)?
I am going to pull the oil pan later this week and see what I find. I will post my findings.
Thanks for the insight