If your oil injector goes out does it sound any alarms before locking up? My merc 150 made a squeak and slowed down then died. Now locked up. Does that sound like a oil injector issue or lower unit? Pulled plugs no obvious signs and still oil on plugs.
It still goes into gears as normal, but the flywheel is locked up

Drop the lower and see if it's still locked up

Depending on the age of the engine, The earlier models did have an alarm on the oil pump to let you know it was turning. The later models do not. A squealing sound could be lower. Do like Martin says and drop the lower unit to be sure.

Its a 2000 model 150 merc, i do know the low oil alarm works, but not in the case. I will drop lower unit after work. Thats better than powerhead, fingers crossed. thanks

Dropped lower unit, motor unlocked and cranked. Nothin but water in lower unit, no grease. Thats better than a power head