i have recently purchased a 2002 ford f150 with the 4.6. it possibly has been sitting a while. every maybe 100 times i go to start it, makes a lou whinning noise. i would rock the truck and it fires up. now its been maybe a month since it has done it. i was going to replace the starter but havnt yet. i was curious of maybe from sitting something could of happened to the starter? maybe rusty or sticking from sitting and now everything is ok? any suggestions. i will keep an eye out on the starter.

 

Try putting a piece of wire from the positive to the wire that comes from the starter. If it starts up then it's not the started. Also make sure the truck is in park

 

It sounds like the drive in the starter is sticking, pull the starter and lube the front and rear bushings and clean lube the shaft that the bendix rides on.