Oil Pressure Diagnosis and Testing 7.0L

Tools Required

1. With the vehicle on a level surface, run the vehicle for a few minutes. Allow adequate drain down time, 2-3 minutes, and measure the oil level.
2. If required, add the recommended grade engine oil and fill the oil tank until the oil level measures full on the oil level indicator.
3. Run the engine briefly, 10-15 seconds, and verify low or no oil pressure on the vehicle gage or lamp.
4. Listen for a noisy valve train or a knocking noise.
5. Inspect for the following conditions:

•	Oil diluted by water or glycol antifreeze

•

Foamy oil

6. Remove the oil filter and install the EN-47971  (1).
7. Install the J 21867  (2), or equivalent to the EN-47971  (1).
8. Run the engine and measure the engine oil pressure.
9. Compare the readings to Engine Mechanical Specifications .
10. If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions:

•	Restricted engine oil tank screen

•	Collapsed or restricted oil hoses

•	Loose oil hose connections at the oil tank or oil pan

•	Damaged oil tank-to-hose or oil pan-to-hose O-ring seals

•	Oil pump worn or dirty

•	Refer to Oil Pump Cleaning and Inspection .

•	Oil pump-to-engine block bolts loose or oil pump mis-aligned to the oil pan rail

•	Refer to Oil Pump and Crankshaft Oil Deflector Installation .

•	Damaged oil pan gasket at oil pump sealing surface damaged

•	Malfunctioning oil pump pressure relief valve

•	Excessive bearing clearance

•	Cracked, porous, or restricted oil galleries

•	Oil gallery plugs missing or incorrectly installed

•	Refer to Engine Block Plug Installation .

•	Broken valve lifters

•	Repair, as necessary.

11. If the oil pressure reading on the J 21867 , or equivalent, is within specifications, inspect for the following conditions:

•	Plugged or incorrect oil filter

•	Malfunctioning vehicle oil pressure gage or engine oil pressure sensor

•	Repair, as necessary.

Oil Pressure Diagnosis and Testing 6.2L LS3

Tools Required

1. With the vehicle on a level surface, run the vehicle for a few minutes, allow adequate drain down time, 2-3 minutes, and measure the oil level.
2. If required, add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.
3. Run the engine briefly, 10-15 seconds, and verify low or no oil pressure on the vehicle gage or light.
4. Listen for a noisy valve train or a knocking noise.
5. Inspect for the following conditions:

•	Oil diluted by water or glycol antifreeze

•

Foamy oil

6. Remove the oil filter and install the EN-47971  (1).
7. Install the J 21867  (2), or equivalent to the EN-47971  (1).
8. Run the engine and measure the engine oil pressure.
9. Compare the readings to Engine Mechanical Specifications.
10. 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 Cleaning and Inspection.

•	Oil pump-to-engine block bolts loose

Refer to Oil Pump, Screen and Crankshaft Oil Deflector Installation.

•	Oil pump screen loose, plugged, or damaged

•	Oil pump screen O-ring seal missing or damaged

•	Malfunctioning oil pump pressure relief valve

•	Excessive bearing clearance

•	Cracked, porous, or restricted oil galleries

•	Oil gallery plugs missing or incorrectly installed

Refer to Engine Block Plug Installation.

•	Broken valve lifters

Repair, as necessary.

11. If the oil pressure reading on the J 21867 , or equivalent, is within specifications, inspect for the following conditions:

•	Plugged or incorrect oil filter and/or malfunctioning oil bypass valve

The bypass valve is now internal to the oil filter.

•	Malfunctioning oil pressure gage or sensor

Repair, as necessary.

Oil Pressure Diagnosis and Testing 6.2L LS9

Special Tools

1. With the vehicle on a level surface, run the vehicle for a few minutes. Allow adequate drain down time, 2-3 minutes, and measure the oil level.
2. If required, add the recommended grade engine oil and fill the oil tank until the oil level measures full on the oil level indicator.
3. Run the engine briefly, 10-15 seconds, and verify low or no oil pressure on the vehicle gage or lamp.
4. Listen for a noisy valve train or a knocking noise.
5. Inspect for the following conditions:

•	Oil diluted by water or glycol antifreeze

•

Foamy oil

6. Remove the oil filter and install the EN-47971 Adapter  (1).
7. Install the J 21867 Gage  (2), or equivalent to the EN-47971 Adapter  (1).
8. Run the engine and measure the engine oil pressure.
9. Compare the readings to Engine Mechanical Specifications.
10. If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions:

•	Piston oil nozzle with a check valve stuck in the open position - indicated by low oil pressure only at idle but not at high speed

•	Restricted engine oil tank screen

•	Collapsed or restricted oil hoses

•	Loose oil hose connections at the oil tank or oil pan

•	Damaged oil tank-to-hose or oil pan-to-hose O-ring seals

•	Restriction within the engine oil cooler

•	Oil pump worn or dirty

Refer to Oil Pump Cleaning and Inspection.

•	Oil pump-to-engine block bolts loose or oil pump mis-aligned to the oil pan rail

Refer to Oil Pump and Crankshaft Oil Deflector Installation.

•	Damaged oil pan gasket at oil pump sealing surface damaged

•	Malfunctioning oil pump pressure relief valve

•	Excessive bearing clearance

•	Cracked, porous, or restricted oil galleries

•	Oil gallery plugs missing or incorrectly installed

Refer to Engine Block Plug Installation.

•	Broken valve lifters

Repair, as necessary.

11. If the oil pressure reading on the J 21867 Gage , or equivalent, is within specifications, inspect for the following conditions:

•	Plugged or incorrect oil filter

•	Malfunctioning vehicle oil pressure gage or engine oil pressure sensor

Repair, as necessary.