Inspection of the Engine Compartment

p4 dm 25.02.000
  1. Check the ground underneath the engine for fuel, oil, or coolant leaks.
  2. Notice: Failure to maintain a sealed air intake system could allow the entry of dirt and contaminants into the engine. This could adversely affect engine performance and result in engine damage.

  3. Inspect the air intake system for leaks or damage.

      Note: The air intake restriction indicator may be located on the air intake or the dash.

    1. Push the reset button on the air intake restriction indicator, if equipped.
    2. Check the air intake duct from the air cleaner to the engine intake. Make sure the duct components are secure and airtight.
  4. Notice: Operating the engine with the oil level below the minimum fill (or "add") mark or above the maximum fill (or "full") mark could result in engine damage.

  5. Check the engine oil level.

      Important: Use only approved engine lube oil. For lists of engine oils approved for Detroit Diesel engines, refer to the Engine Operator Manual, accessible on Lubricants, Fuels & Coolants on the DTNA Portal. For third party engines, please refer to the engine manual.

    1. Check the oil level with the vehicle parked on a level surface. See the engine manufacturer's guidelines for engine shutdown time requirements prior to checking the oil level.
    2. If the oil level is at or below the minimum fill (or "add") mark on the dipstick, add enough oil to maintain the level between the minimum and maximum fill marks. See the engine operation manual for recommended lubricants.
  6. Check the power steering reservoir fluid level.

    The power steering fluid level should be between the MIN COLD mark and the middle mark just above it. See Fig.. If needed, fill the reservoir with automatic transmission fluid that meets Dexron III or TES-389 specifications.

    Note: Typical reservoir shown; configurations may vary.

    1. Filler Cap

    2. MAX Fill Line

    3. COLD MIN Fill Line

    Fig. 1, Power Steering Fluid Reservoir

  7. Important: The surge tank must be cool to check the coolant level.

    Notice: Low coolant could result in engine overheating, which could cause engine damage.

    Notice: Coolant must be filled to the COLD MAX line of the surge tank. Low coolant could result in engine overheating, which could cause engine damage.

  8. Check the engine coolant level in the radiator surge tank. See Fig..
    1. Pressure Relief Cap

    2. Filler Cap

    3. COLD MAX Fill Line

    4. COLD MIN Fill Line

    Fig. 2, Coolant Surge Tank

    1. If the coolant is low, fill the surge tank to the MAX line with a 50/50 mixture of water and the type of antifreeze currently installed in your vehicle.
    2. If the surge tank was empty, start the engine after refilling and check the level again when the engine is at operating temperature.
  9. Inspect visible engine wiring for damage or looseness. Check for loose wiring, chafed insulation, and damaged or loose hold-down clamps.
  10. Inspect visible frame rails for missing bolts, shiny areas, or rust streaks.
Note:
INSPECT
Document Number: 0000111592
Manual Publication Date: 2025-03-10
Topic Publication Date: 2026-09-01