Engine Will Not Crank - Crankshaft Will Not Rotate

Cause	Correction
Seized accessory drive system component	Remove accessory drive belt or drive belts. Rotate crankshaft by hand at the crankshaft balancer or engine flywheel location. Repair or replace as required.
Hydraulically locked cylinder Coolant/Antifreeze in cylinder Oil in cylinder Fuel in cylinder	Remove spark plugs and check for fluid. Inspect for broken head gasket or gaskets. Inspect for cracked engine block or cylinder head. Inspect for a sticking fuel injector. Repair or replace as required.
Seized or broken camshaft	Inspect camshaft or camshafts. Inspect cylinder head camshaft journals for damage. Repair as required.
Seized or broken camshaft timing components	Inspect the following sprockets: Crankshaft sprocket Exhaust sprockets Intake sprockets Inspect the timing belt. Inspect the following tensioners: Timing belt idler pulley for camshaft gears 1 and 2 Timing belt idler pulley for camshaft gears 3 and 4 Timing belt tensioner Repair as required.
Seized or broken valve train components	Inspect lifters. Inspect valves. Inspect cams. Repair as required.
Seized automatic transmission torque converter	Remove the torque converter bolts. Rotate crankshaft by hand at the crankshaft balancer or engine flywheel location. Repair or replace as required.
Seized manual transmission	Disengage the clutch. Rotate crankshaft by hand at the crankshaft balancer or engine flywheel location. Repair or replace as required.
Material in cylinder Broken valve Piston material Foreign material	Inspect cylinder 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.