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 Will Not Crank - Crankshaft Will Not Rotate

Cause

Correction

Seized accessory drive system component
  1. Remove the accessory drive belts.
  2. Confirm that the engine will rotate. Rotate the crankshaft by hand at the crankshaft balancer or flywheel location.
  3. Repair or replace the components as required.

Seized automatic transmission torque converter
  1. Remove the torque converter-to-flywheel bolts.
  2. Confirm that the engine will rotate. Rotate the crankshaft by hand at the crankshaft balancer or flywheel location.
  3. Repair or replace the components as required.

Broken timing chain
    • Inspect the timing chain and gears.
    • Repair or replace the components as required.

Seized timing chain or timing gears
    • Inspect the timing chain and gears for foreign material or a seized chain.
    • Repair or replace the components as required.

Seized or broken camshaft
    • Inspect the camshaft and the camshaft bearings.
    • Repair or replace the components as required.

Bent valve in the cylinder head
    • Inspect the valves and the cylinder heads.
    • Repair or replace the components as required.

Seized oil pump
    • Inspect the oil pump assembly.
    • Repair or replace as required.

Hydraulically locked cylinder

    • Coolant/antifreeze in the cylinder
    • Oil in the cylinder
    • Fuel in the cylinder
  1. Remove spark plugs and check for fluid in the cylinder. When rotating the engine with the spark plugs removed, the piston, on compression stroke, will push fluid from the combustion chamber. Refer to Coolant in Combustion Chamber .
  2. Inspect for failed/broken head gaskets.
  3. Inspect for a cracked engine block or cylinder head.
  4. Inspect for a sticking fuel injector.
  5. Repair or replace the components as required.

Material in the cylinder

    • Broken valve
    • Broken piston rings
    • Piston material
    • Foreign material
    • Inspect the cylinder for damaged components and/or foreign materials.
    • Repair or replace the components as required.

Seized crankshaft or connecting rod bearings
    • Inspect crankshaft and connecting rod bearings.
    • Repair or replace the components as required.

Bent or broken connecting rod
    • Inspect the connecting rods.
    • Replace the piston, pin and connecting rod as an assembly, as required.

Broken crankshaft
    • Inspect the crankshaft.
    • Repair or replace the components as required.