Engine Will Not Crank - Crankshaft Will Not Rotate

Cause	Correction
Seized accessory drive system component	Remove the accessory drive belt. Rotate the crankshaft by hand at the crankshaft balancer or the engine flywheel location. Repair or replace components as required.
Seized starter motor	Replace as required.
Hydraulically locked cylinder Coolant/Antifreeze in cylinder Oil in cylinder Fuel in cylinder	Remove the spark plugs and check for fluid in the cylinder bore. Inspect for a sticking fuel injector. Inspect for a failed cylinder head or gasket. Inspect for a cracked engine block. Repair or replace as required.
Seized automatic transmission torque converter	Remove the torque converter bolts. Rotate the crankshaft by hand at the crankshaft balancer or the engine flywheel location. Repair or replace as required.
Material in cylinder Broken valve Piston material Foreign material	Inspect the cylinder for damaged components and/or foreign materials. Repair or replace as required.
Seized crankshaft or connecting rod bearings	Inspect the crankshaft and the connecting rod bearings. Repair as required.
Bent or broken connecting rod	Inspect the connecting rods. Repair as required.
Broken crankshaft	Inspect the crankshaft. Repair as required.
Seized or broken camshaft	Inspect the camshafts. Inspect the cylinder head camshaft journals for damage. Repair as required.
Broken or mis-aligned camshaft timing components	An improperly installed timing belt may lead to valve-to-piston contact.
Seized or broken valve train components	Inspect the rocker arms. Inspect the lash adjusters. Inspect the valves. Inspect the valve springs. Repair as required.