The oil pump supplies pressurized oil to the bearings, camshaft(s), and valvetrain. During an engine rebuild, many professional rebuilders replace the oil pump as standard practice rather than reusing the original. Here is why, and what else to check in the lubrication system.
Why Replace the Oil Pump
- Wear: internal clearances in the pump increase with use, which can reduce oil pressure and flow.
- Debris: if the engine failed, metal particles may have passed through the pump and damaged it.
- Cost versus risk: the cost of a new pump is small compared with the cost of the bearings, crankshaft, and labor it protects.
Check the Pickup Tube and Screen
The pickup tube and screen deliver oil from the pan to the pump. Clean or replace a clogged screen, and inspect the tube for cracks. Make sure the pickup seals correctly to the pump, using a new gasket or O-ring where specified, because an air leak at the pickup can starve the engine of oil.
Confirm the Correct Pump
Oil pump design, drive type, and pickup configuration vary by engine. Confirm the pump matches the engine application, and follow the installation instructions, including any specified clearances and fastener torque values.
Prime Before First Start
A freshly assembled engine has dry oil passages. Prime the lubrication system before the first start, using the method recommended for the engine, and confirm oil pressure immediately after startup.
Evergreen Oil Pumps and Rebuild Kits
Evergreen oil pumps are identified by application, and depending on the part number, Evergreen engine rebuild kits may include an oil pump. Use the Evergreen eCatalog to find the right pump or kit for your engine.
