Anyone know what this is?

 

At first it looked like a socket. But its a valve guide

 

It's small. The hole down the center is tiny. I was thinking too small for a valve to fit. I was guessing this might be a rocker arm piston but I never seen one of those let alone a valve guide. Engine was knocking and valvetrain was noisy. Pulled the valve cover off last night and found it sitting in between rocker arms. Head was recently built. Looks like I got a big problem.

 

That is a rocker arm piston, or as we call it in the UTH forum a VTEC pin.

It is IMPOSSIBLE for that pin to come out once assembled, the engine was built that way and who ever did it dropped that pin where you found it.

 

I'd also look for missing lost-motion springs under the rockers, there are 8 of them. One under each middle rocker.

This can be fixed in 20 minutes if you're good.

Remove cam caps and cams, flip each rocker assy up and find the one with the missing pin.

I'd check every single one, each 3 piece rocker has one large hollow pin (your pic) and one short solid pin that can go missing during assembly.

 

It looks like the rocker synchronizing pin, it locks the middle piece when vtec engages, I used elastic band to hold the three piece rocker arms when removing rocker arms, otherwise it will be a mess to put together. Definitely check all rockers, can't image the consequence...

 

Thanks everyone. Billman, I can see all 8 LMA's. Initially that is why I pulled the cover to confirm that they were installed. A friend of mine thought maybe they were forgotten and causing my knock. Then I saw this pin just sitting there. I use Flashpro and ever since the head work my car has been pulling timing with massive loss of power. I noticed higher than normal knock counts. Then finally one day I got a lot of counts and a CEL for the knock sensor. I am SOS supercharged and the blower is loud. I pulled the belt off to hear better and the valvetrain was noisy.

 

Cams will be the last parts you lift out, do not pull the rockers. Just flip each up and check for 16 pins.

 

 

Awesome info. I will have a go at it tomorrow. Thanks again.