Section 2.2
Improper Lubricating Oil Viscosity

To determine if improper lubricating oil viscosity is causing low oil pressure, perform the following steps:‪

1. Acquire a lubricating oil sample from the engine oil pan.
2. Submit oil sample for an ASTM test analysis.
   1. If engine oil sample meets ASTM specifications, check to determine if lubricating oil is diluted with fuel or coolant; refer to "2.3 Lubricating Oil Diluted With Fuel Oil or Engine Coolant" .
   2. If engine oil sample did not meet ASTM specifications, drain and refill engine with new lubricating oil; refer to appropriate service manual, preventive maintenance chapter.
3. Verify lubricating oil replacement, refer to .

Section 2.2.1
Test Engine with Replaced Lubricating Oil

Perform the following steps to determine if replaced lubricating oil resolved low oil pressure:‪

1. Connect to DDDL 7.0.
2. Start and run engine speed at 1800 rpm.
3. Check DDDL 7.0 for the for oil pressure reading.
   1. If DDDL 7.0 indicates oil pressure greater than or equal 241 kPa (35 psi) at 1800 rpm, shut down the engine and disconnect DDDL 7.0. No further troubleshooting is required.
   2. If DDDL 7.0 indicates oil pressure less than 241 kPa (35 psi) at 1800 rpm, shut down the engine and disconnect DDDL 7.0. Check the lubricating oil for fuel and water dilution; refer to "2.3 Lubricating Oil Diluted With Fuel Oil or Engine Coolant" .