Cobalt L4-2.4L VIN B (2006)
Engine Oil Pressure: Testing and Inspection
Oil Pressure Diagnosis and Testing
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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 gage or light. Listen for a noisy valve train or a knocking noise.
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Inspect for the following:
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Oil diluted by moisture or unburned fuel mixtures
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Improper oil viscosity for the expected temperature
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Incorrect or malfunctioning oil pressure sender
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Incorrect or malfunctioning oil pressure gage
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Plugged oil filter
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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 an oil pressure gage and measure the engine oil pressure.
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Compare the readings to specifications. Refer to Engine Mechanical Specifications.
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If the engine oil pressure is below specifications, inspect the engine for one or more of the following:
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Oil pump worn or dirty - Refer to Oil Pump Disassemble.
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Oil pump-to-engine front cover bolts loose Refer to Engine Front Cover and Oil Pump Installation.
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Oil pump screen loose, plugged, or damaged
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Oil pump screen O-ring seal missing or damaged
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Malfunctioning oil pump pressure regulator valve
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Excessive bearing clearance - Refer to Crankshaft and Bearings Cleaning and Inspection.
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Cracked, porous or restricted oil galleries
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Oil gallery plugs missing or incorrectly installed - Refer to Engine Block Assemble.
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Broken lash adjusters
