Engine Will Not Crank - Crankshaft Will Not Rotate

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Correction
Seized accessory drive system component or starter motor	Remove accessory drive belt or belts and/or starter motor. Rotate crankshaft by hand at the balancer or flywheel location.
Broken timing chain	Inspect timing chain, gears and crankshaft sprocket locating pin. Repair as required.
Seized camshaft	Inspect camshaft and camshaft bearings. Repair as required.
Bent valve in cylinder head	Inspect valves and cylinder heads. Repair as required.
Hydraulically locked cylinder: Coolant/antifreeze in cylinder Oil in cylinder Fuel in cylinder	Remove spark plugs and check for fluid. Inspect for a sticking fuel injector. Inspect for broken head gasket or gaskets. Inspect for cracked engine block or cylinder head.
Seized automatic transmission torque converter	Remove the torque converter bolts. Rotate crankshaft by hand at the balancer or flywheel location.
Seized manual transmission	Disengage the clutch. Rotate crankshaft by hand at the balancer or flywheel location.
Material in cylinder: Broken valve Piston material Foreign material	Inspect cylinder and cylinder head for damaged components and/or foreign materials. Repair or replace as required.
Seized crankshaft or connecting rod bearings	Inspect crankshaft and connecting rod bearings. Repair as required.
Bent or broken connecting rod	Inspect connecting rods. Repair as required.
Broken crankshaft	Inspect crankshaft. Repair as required.