Not a chevy sbc, this is a 302 FI in my F150:
Had an oil pressure problem all of a sudden ranging from normal to 0. As I increased rpm
"slightly" the oil pressure moved toward 0 and let off the throttle it went back to normal. I removed the oil pump and screen and found the screen clogged real bad. Checked all of the main bearings/journals and they are good and within specs. Have not taken the pump apart yet. But # 3 thrust bearing on one exterior side is pratcticlly gone. Cut open oil filter and found no metal particles. But in the pan found a skin piece of the # 3 bearing thrust side metal. Bearing side worn was toward rear of engine . My guess is this happened in short order and probably the screen plugged restricted oil circulation and somehow toasted the exterior side of the bearing. I am replacing the oil screen and pump. Of course the crankshaft end play is way out.
Note, measured all of the bearings at journals are good, the engine does not have any noises...knocks etc., I'm planning on just replace the thrust bearing and if the end thrust clearance is ok, just leave the engine as is and drive it.
This is the original 302FI in my F150 extended cab, never had any issues with oil/pressure before. Been using Mobil 1. About 125K on engine.
This just baffles me how this happen without damaging any bearing surfaces? Any thoughts Phil
Had an oil pressure problem all of a sudden ranging from normal to 0. As I increased rpm
"slightly" the oil pressure moved toward 0 and let off the throttle it went back to normal. I removed the oil pump and screen and found the screen clogged real bad. Checked all of the main bearings/journals and they are good and within specs. Have not taken the pump apart yet. But # 3 thrust bearing on one exterior side is pratcticlly gone. Cut open oil filter and found no metal particles. But in the pan found a skin piece of the # 3 bearing thrust side metal. Bearing side worn was toward rear of engine . My guess is this happened in short order and probably the screen plugged restricted oil circulation and somehow toasted the exterior side of the bearing. I am replacing the oil screen and pump. Of course the crankshaft end play is way out.
Note, measured all of the bearings at journals are good, the engine does not have any noises...knocks etc., I'm planning on just replace the thrust bearing and if the end thrust clearance is ok, just leave the engine as is and drive it.
This is the original 302FI in my F150 extended cab, never had any issues with oil/pressure before. Been using Mobil 1. About 125K on engine.
This just baffles me how this happen without damaging any bearing surfaces? Any thoughts Phil