| • | J 21867 Pressure Gage |
| • | J 42907 Oil Pressure Tester |
| • | Oil diluted by water or glycol antifreeze |
| • | Foamy oil |
| • | Oil pump worn or dirty. Refer to Oil Pump Replacement , Oil Pump Disassemble and Oil Pump Cleaning and Inspection . |
| • | Oil pump-to-engine block bolts loose. Refer to Oil Pump Replacement . |
| • | Oil pump screen loose, plugged, or damaged. Refer to Oil Pump Suction Pipe and Screen Assembly Replacement . |
| • | Oil pump screen O-ring seal missing or damaged. Refer to Oil Pump Suction Pipe and Screen Assembly Replacement . |
| • | Oil pump pressure relief valve malfunction. Refer to Oil Pump Replacement . |
| • | Engine bearing clearance excessive. Refer to Crankshaft and Bearing Cleaning and Inspection , Crankshaft and Bearing Installation and Piston, Connecting Rod, and Bearing Installation . |
| • | Cracked, porous, or restricted oil galleries. |
| • | Oil gallery plugs missing or incorrectly installed. Refer to Engine Block Assemble and Cylinder Head Assemble . |
| • | Valve lifters broken. Repair, as necessary. Refer to Valve Lifter Replacement - Left Side and/or Valve Lifter Replacement - Right Side and Valve Lifters Cleaning and Inspection . |
| • | Plugged or incorrect oil filter and/or malfunctioning oil bypass valve. Refer to Engine Oil and Oil Filter Replacement . |
| • | Malfunctioning oil pressure gage or sensor. Repair, as necessary. Refer to Engine Oil Pressure Sensor and/or Switch Replacement . |