Inspection of the Engine Compartment

p3 dm 21.02.000

  1. Check the ground underneath the engine for fuel, oil, or coolant leaks.
  2. Inspect the air intake system for leaks or damage.

    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.
      1. Push the reset button on the air intake restriction indicator located on the air cleaner, 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.
    1. Check the engine oil level.

      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.
        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.

          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. 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.

            For natural gas vehicles, use only Exxon Busgard® Geo 15W-40 natural gas engine oil.

        2. 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

          Fig. 1, Power Steering Fluid Reservoir

          3. 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.

        3. 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

          5. Coolant Level Sensor

          Fig. 2, Coolant Surge Tank

          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.
            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.

              For natural gas vehicles, use only Fleetguard ES Compleat™ EG Premix 50/50 engine coolant.

            2. If the surge tank was empty, start the engine after refilling and check the level again when the engine is at operating temperature.
          1. Inspect visible engine wiring for damage or looseness. Check for loose wiring, chafed insulation, and damaged or loose hold-down clamps.
          2. Inspect visible frame rails for missing bolts, shiny areas, or rust streaks.
          Note:
          Parent topic: Daily Pretrip Inspections and Maintenance
          Document Number: 0000112411
          Manual Publication Date: 2025-02-11
          Topic Publication Date: 2025-03-18