Almost looks like the end of a bolt that had been drilled out to remove after maybe a head snapped off?? Look at the divot in the center, like something a drill would leave if someone drilled a broken bolt out???

Many a sleepless night are in your future wondering WTF this little critter is.
Unless of course you send this thread by link to 200 of your closest friends, then you will have good luck for 7 years and fall in love inside of a week!!

Seriously, I hope it's nothing.

 

That's what I was thinking, the concave part looks like it was drilled...

 

The diameter looks similar to a valve stem, you would know if that came apart. Could also be a drilled bolt from somewhere as stated, maybe it fell in from somewhere else at some point. Its time for self diagnosis at this point, if the truck thinks that it needs that part it wil be sure to let you know.

 

LMAO... yea... who needs bolts anyways?

 

maybe its that damn'd sasquatch again!

 

i found a similar piece of metal like that before in my pan. it had turned out to be part of the front cover where the front 10mm bolts go thru. i had alittle to much Right Stuff and when i torqued the cover down the Right Stuff had cracked the cover where the bolt proceeds. nothing major of the cover still using it

 

that is awesome