GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Yukon - 4WD 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, and 6.0L 🢒 Engine Block Valley Cover Cleaning and Inspection

    Object Number: 490851 Size: SH

    Important: 

       • Do not use the valley cover knock sensor oil seals again. Install NEW oil seals during assembly.
       • Do not use the valley cover gasket again. Install a NEW gasket during assembly.

  1. Remove the knock sensor oil seals (1) from the valley cover (2).
  2. Clean the valley cover in solvent.

    3. Caution: Wear safety glasses in order to avoid eye damage.

  3. Dry the valley cover with compressed air.
  4. Inspect the gasket sealing surfaces for excessive scratches or gouging. Refer to Replacing Engine Gaskets .
  5. Inspect the valley cover oil seal bores for excessive scratches or gouging.