Yep, I earn the dumbass award for this;
Doing head gaskets on my 04 and as I was removing the nut to the strap ground at the firewall the nut got away from me and all I heard was 1 plink and poof it was gone. Of course, I had already removed valley pan gasket and was not covered, I have been through engine bay, on top of trans, frame rails and every inch of the garage and no nut in sight. I have no other option but to believe it fell in the block, surely, I'm not the only that has done this lol. I'm guessing drain the oil and hope it comes out and in the event that it doesn't I assume I will have to pull the oil pan and find the damn thing. Any other suggestions to those who have gone before me lol?

 

If you pull the oil pan, check on top of the crankshaft.

 

Me, l'd rotate engine at crank by hand slowly. Most likely, if it "even did" go int engine to begin with (which we are unsure of), it made it's way to the pan, or will. Once it's in the pan...that's where it will stay. Maybe, eventually, it may slide over to the plug...but if not...it will just lay in the bottom of the pan, causing no issue. After 40 some years of being a mechanic...you'd not believe the things l've found down there. It can not be picked up through the oil pump screen/tube.

Now, this is what l would do...yours and others views may differ.

 

If this helps, removing the pan is not hard and it's nice to know there is no sludge down there after cleaning it up before reinstalling it.

 

Maybe there's something I'm not remembering, but what's open with the valley pan gasket removed? As I recall, the lifters are visible in their bores but I don't recall there's anywhere a nut that size can find its way into an oil passage from there. The intake ports on the heads are open, of course, but if the nut went into one of them you ought to be able to retrieve it when you remove the head by simply turning the head over and shaking it. What am I missing?

 

Thanks The Deputy, I was thinking of manually turning the engine to hopefully make sure it did go to the pan, even if it did fall in lol, damn nut worse than a 10mm socket for crying out loud!

 

if it can slip past the cam down it goes lol plenty of room for that nut to get past there from what I remember.