Technical Bulletins

Engine Oil System Priming Procedures for
1995-2006 Ford Engines

The AERA Technical Committee offers the following information regarding engine oil system priming on Ford engines. This information should be referenced any time a new or remanufactured engine is installed.

Reports of premature engine failure suggest some overhauled, new and/or remanufactured engine oil systems are not correctly primed prior to initial engine start-up, after being installed in the vehicle. This may cause oil starvation during initial engine start-up.

Prior to starting a new, overhauled or remanufactured engine, the oil pump and oil system should be primed to eliminate the possibility of oil starvation at start-up. Refer to the following Ford Service Information for details.

Overhead Cam Engines (OHC):

Ford overhead cam engines use a G-rotor pump design that is driven by the crankshaft. If the engine is overhauled, the oil pump (prior to assembly) should be fed oil through the oil pick-up passage, prior to installing the pick-up tube and screen assembly. This can usually be accomplished by rotating the oil pump while oil is being fed into the oil pump inlet. Once the oil pump is primed, the oil pump can then be installed onto the engine.

Overhead cam engines, whether overhauled or remanufactured, prior to starting the engine, ensure the engine crankcase is filled to specification with engine oil. Disable the fuel supply to the fuel injectors (disable inertia fuel shut-off switch) and crank the engine in fifteen (15) second increments, until the oil pump is primed. An oil pressure gauge can be used to assist in determining when oil pressure is obtained.

NOTE: Ensure the inertia fuel shut-off switch is re-enabled prior to attempting to start engine.

Overhead Valve Engines (OHV):

Overhead valve engines (push-rod type) use an oil pump driven by the camshaft via an intermediate shaft connected to the distributor or camshaft synchronizer assembly.
Whether the engine is overhauled or remanufactured, the oil pump should be primed prior to starting the engine. If the engine is overhauled, ensure the crankcase is filled to specification with the proper engine oil and using an engine oil pump priming tool kit, (commercially available) rotate oil pump until it is primed. An oil pressure gauge can be used to assist in determining when oil pressure is obtained.

If a remanufactured engine is being installed, after the installation has been completed, ensure the crankcase is filled to specification with engine oil. Disable the fuel supply to the fuel injectors (disable inertia fuel shut-off switch) and crank the engine in (15) second increments, until the oil pump is primed. An oil pressure gauge can be used to assist in determining when oil pressure is obtained.

NOTE: Ensure the inertia fuel shut-off switch is re-enabled prior to attempting to start engine. If the engine does not start by the 3rd attempt, stop and determine why as cylinder wall fuel wash has already started.

Regardless of engine design, it is extremely important that the engine oil pump is correctly primed, prior to initial engine start-up.

The AERA Technical Committee