How badly screwed am I?

It would be difficult to drop it in the cylinder and you not notice installing the head gasket and head.
But, you can try a bore scope and look through the spark plug holes....
A lifter is a pretty big piece to lose, but replacing it with one new one shouldn't be a problem.
You should not have to remove the head, again.
And I'm certain you will find it, after you've put eveything back together!
It's happened to all of us!

 

Good excuse to buy a cheap wifi endoscope that works with your phone. Handy.

Or fish in each spark plug hole with a small magnetic pick up tool.

Whatever it is you lost (lifter seems unlikely to me, maybe a keeper?) you can buy individually.

See here

 

The good news is that the Gen 3 'lifters' (if you are referring to the hydraulic last adjusters that sit underneath the rocker arm at the opposite end from the valve) are self-adjusting and identical, so there is only one part number and you buy it and put it there and it works.

If you were working on a Gen 1 or Gen 2 (or c) where the intake and exhaust lifters are different and come in 35 sizes each, you would be having a worse day.

 

Glad you found it

 

That quote is true, but there are endoscopes that aren't medical devices, and I own one. (It works well, but the TOS for the app is a little strange and concerning to some).

The difference between a borescope and an endoscope is that an endoscope looks out the end of the device, and a borescope looks at 90 degrees (so it can inspect the inside of a bore).

 

Every, hmm, cheap skinny inspection camera that I've owned has looked out the end, but has also come with an angled-mirror attachment to clip on the end and supposedly get a side view.

In the interest of full disclosure, I think I have never ever achieved a usable side view of anything using any of those little mirrors.

 

***Glad you found it even if you had to pull the head first*** (Response from the Op was delayed by mod)

The point is a reasonably priced (~$40) borescope/endoscope and your phone does wonders and the Op does not need to be scared off by expensive devices that might otherwise be found.

For example this Tulsa weatherman uses a wireless "camera scope" on his project bmw in the first couple of minutes. He gets a good look at the piston and walls with decent focus lacking in the sub $20 versions.

His "camera" seems to be the same Depstech Wireless I have had for the last for years.

 

I'm glad you found it, sorry you pulled the head though.
Did you order a new head gasket also? They are really a one time use item.
Since you ordered new head bolts, it would be wise to order a new head gasket.
You certainly don't want it to fail after all your work!

 

I have a habit of threading bolts a couple turns back in to wherever they came out of as a way of keeping track of them.

I recently swapped some EGR components with pre-cleaned ones I had bought from another member. Putting it all back together, I spent probably an hour searching in vain for one last bolt to hold a silly wire harness standoff to the valve.

Of course I later found it, safely threaded into the hole it came out of, in the other valve.

 

I've gotten into the habit of setting nuts, bolts and various small removed pieces on an adjacent window ledge, going from left-to-right, as I take them off the car, and below each item or group I put a masking tape label. If it was something as involved as a head gasket I'd "need a bigger ledge" though....

 

+1

moto g power ?