Purpose
To determine if crankcase oil level and oil quality are correct to ensure operation of the Injection Control Pressure (ICP) system
Tools
• None
Procedure
1. Park vehicle on level ground.
2. Check oil level with oil level gauge.
NOTE: Never check the oil level when the engine is running or immediately after the engine is shut down; the reading will be inaccurate. Allow 15 minute drain down time, before checking oil level.
NOTE: If the oil level is too low, the fuel injectors will not work correctly. If the oil level is above the operating range, the engine has been incorrectly serviced, fuel is in the oil, or coolant is in the oil.
3. Inspect oil for thickening.
NOTE: When the crankcase lube oil is contaminated with coolant, the oil will have a dark-gray or black sludgy appearance.
• Engine oil level will vary depending on temperature of engine.
• If oil is contaminated, see “Fuel in Lube Oil” (page 124) or “Coolant in Lube Oil” (page 109) in Section 4.
• If oil level is low, fill to correct level and test again.
4. Check engine service records for correct oil grade and viscosity for ambient operating temperatures.
Do not use 15W-40 oil below -7 °C (20 °F). Long oil drain intervals can increase oil viscosity; thicker oil will make engine cranking and starting more difficult below freezing temperatures. See “Lubrication Requirements” in the Engine Operation and Maintenance Manual (for this engine’s model number and model year). Confirm that oil meets correct API category.
5. Record concerns on Diagnostic Form.
Possible Causes
Low oil level
• Oil leak
• Oil consumption
• Incorrect servicing
High oil level
• Incorrect servicing
• Fuel in oil
• Coolant in oil
• Incorrect oil level gauge
Coolant in oil
• Cylinder head gasket leak
• Failed cup plug in cylinder head
• Injector sleeve leak
• Front cover gasket leak
• Front cover, cylinder head, or crankcase porosity
• Accessory leak (water cooled air compressor)
• Failed crevice seal (piston sleeve)
Fuel in oil
• Injector O-ring leak
• Cylinder head porosity
• Leaking injector
