Oil Pressure Diagnosis and Testing

Special Tools

EN 21867-850 Oil Pressure Gauge Adapter

For equivalent regional tools, refer to Special Tools .

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With the vehicle on a level surface, allow adequate drain down time of 2-3 minutes and measure for a low oil level.

Add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.

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Run the engine, and verify low, or no oil pressure on the vehicle gauge or light.

Listen for a noisy valve train or a knocking noise.

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Verify the following:

Oil diluted by moisture or unburned fuel mixtures

Improper oil viscosity for the expected temperature

Incorrect or malfunctioning oil pressure sender

Incorrect or malfunctioning oil pressure gauge

Plugged oil filter

Malfunctioning oil bypass valve

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Remove the oil pressure sender or another engine block oil gallery plug.

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Install EN 21867-850 adapter and an oil pressure gauge and measure the engine oil pressure.

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If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions:

Oil pump worn or dirty - Refer to Oil pump dismantling

Oil pump-to-engine front cover bolts loose-Refer to Oil Pump Installation .

Oil pump screen loose, plugged, or damaged

Oil pump screen O-ring seal missing or damaged

Oil pump to oil pump pipe and screen assembly gasket missing or damaged

Oil pump pipe and screen assembly restrictions or damaged

Oil pump driven gear damaged or loose

Oil pump drive gear damaged

Malfunctioning oil pump pressure regulator valve

Excessive bearing clearance-Refer to Crankshaft and Bearing Cleaning and Inspection .

Cracked, porous or restricted oil galleries

Oil gallery plugs missing or incorrectly installed-Refer to Engine Block Assemble .

Broken lash adjusters

Oil cooler restrictions

Oil cooler O-rings damaged or missing

Cracked, porous or restricted oil galleries

Damaged or missing oil spray cooling nozzles