99 5.4 locked up?
 

Friend of mine has a 99 f150 w/ a 5.4. Was running
Fine till one day wouldn't start. Like it wouldn't turn over
Then got it started and seemed to run fine for a few days
Till one day wouldn't start again. Had a shop look at it, and they said
The motor is locked up, can bar it over backwards but not forward?
Any ideas?? I'm going to check it out when he gets it
Back. What should I look for. Is the motor doa?