Incorrect Oil Pump Seal Facing Installation

This engine had excessive vibration at 4200 rpm and up. It also had slightly low oil pressure. The oil pressure is specified as 12 psi minimum. The oil pressure would go to down to 10 psi when hot. The project was to disassemble this engine to balance the rotating assembly. We encountered a surprise when preparing to remove the oil pump.

The engine was previously serviced by an unknown shop to repair a broken right camshaft timing chain. During the reassembly the facing ring for the oil pump seal was installed upside down.

The oil pump has a floating carbon seal that is coaxed over the crankshaft snout. The front face of the seal is designed to be sealed with the flat surface of a ring that rotates with the crankshaft. The other side of the ring is tapered to mate with the base of the torsional damper. The ring was installed with the tapered side facing the seal. The taper wedged the seal outward and split the carbon seal.

The picture shows the oil seal facing ring withdrawn an inch away from the pump. The flat face of the ring is incorrectly facing toward the torsional damper. Two cracks in the carbon seal can be seen along with a piece of the seal that broke off and fell out.