
The first common problem is running the engine with no oil. This is usually caused by an oil leak or accidentally running the engine without oil after an oil change.
The second common problem is hydrolock caused by a head gasket issue, cracked engine block, cracked cylinder head, stuck open fuel injector (fouling out spark plugs), or somehow water got into the throttle/intake.
Third common problems is spun bearing (normal wear and tear) or dirty engine oil.
Fourth common problem is failed oil pump cause zero engine oil circulation.