Starter motor from your description. Have it checked to verify
October, 13, 2012 AT 6:08 PM
Squeaal is usually associated with starter drive consisting of gear and 1 way clutch. When clutch slips it is known to make a loud high pitched squeal noise. Hard to test for off vehicle. If slip is bad enough motor will not turn over.
October, 13, 2012 AT 9:43 PM
If it sits over night it cranks without a problem. It seems to happen more when the engine is still hot. But if the engine is cold it works just fine