Well its not like that nut can go far, its most likely gonna fall into your oilpan and that tick is either injectors or that valve is gonna be need adjusting...The nut can do damage if it somehow gets jammed into a valve spring but if it falls into the oil pan, it will just sit there since the pickup will prevent it from going into your oilpump...

 

I just assumed he would com across it on his next oil change or someone left it off in the first place.

 

LOL

I would be worried sick about that nut getting stuck in one of the oil channels.

 

the oil passages dont seem large enough to allow one of those nuts to fall through.

Seems to me that if the nut actually fell off when driving it would have gotten jammed down between springs.

and for the tapping. me 3 for the valve adjustment.
correct me if im wrong but isnt around .006 intake .008 exaust