I went to leave work earlier this afternoon and fired up the truck its a 1979 f150 with a 400m, re-manned crate engine, and the moment i fired it up, it had a sharp rattle scraping type sound coming from the engine, and what sounded like the drivers side valve cover, i thought something terrible had happened to my engine, but it never made a peep on the way to work or ever before.

i shut the truck off after walking around it trying to figure out the source of the sound and started it back and up BAM its gone completely! no noise or nothing.

i have no real clue as to what it was or what it could be. my oil pressure was good it was at 75 psi

 

Well sounds like the starter and flywheel did not agree, but that's the wrong side for where you think it came from.

 

I agree. If I were you I would make sure starter is tight

 

well i guess it was the starter, and it took me a minute or so to figure that out before i shut it off..

now when i go to start it , its not engaging with the flywheel, it just spins. looks like i need a starter now.

 

Try turning the engine just a little by hand. See if starter engages flywheel then. If it does you need new ring gear on flywheel if standard or new flex plate if automatic.

 

Pull the starter and inspect the drive teeth and insp the flywheel for chipped or broken teeth. Easy fix if it just the starter, also insp the flywheel teeth edge to be worn, cause by the starter not engaging fully.

Starter Service repair diagnosis symptoms bad starter help

 

well it always started hard before this, cranked very slowly, so maybe it is worn out. ill check it out!

 

Clean your battery to block grounds and insp you battery cables for swelling. Get a quality starter with a life time warranty.