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What usually causes this fault here is a faulty valve lash adjuster.These can fail and causes a rattle noise on the cam shaft with the engine running.If you have no warning lights and the engine is not knocking and is running o.k. I suspect the lash adjusters need replaced.The valves cover needs removed to access and replace these.The part numbers are 24100005 ans you should have 16 of these.They are around $10 each in most cases.This can run up to around 6 hours labor to have all replaced.
The oil pressure does need tested.The procedure and possible causes are listed below if you have a low oil pressure issue:
J 44953 Oil Pressure Gage Adapter
- 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.
- 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.
- Inspect for:
- 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 gage
- Plugged oil filter
- Malfunctioning oil bypass valve
- Remove the oil pressure sender or another engine block oil gallery plug.
- Install J 44953 and an oil pressure gage and measure the engine oil pressure.
- Compare the readings to specifications. See: Engine Oil Pressure > Specifications
- If the engine oil pressure is below specifications, inspect the engine for one or more of these:
- Oil pump worn or dirty.
- Oil pump-to-engine front cover bolts loose.
- Oil pump screen loose, plugged, or damaged
- Oil pump screen O-ring seal missing or damaged
- Malfunctioning oil pump pressure regulator valve
- Excessive bearing clearance.
- Cracked, porous or restricted oil galleries
- Oil gallery plugs missing or incorrectly installed.
- Broken lash adjusters
Oil Pressure - Minimum
@ 1,000 RPM ................................ 344.75 - 551.60 kPa (50 - 80 psi)
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