Stuck Valve Thrust Piece / Washer

[baon3h]

On my quest to find the source of a noticeable tapping noise, I noticed that the thrust piece on a valve was stuck in the valve spring retainer at an angle. Others move freely, this one doesn't budge. This would explain my trouble getting this valve adjusted properly and might be the source of the tapping noise.

Now my question is if I can tap the top of the thrust piece with a hammer and get it back to seat properly or would that cause additional damage? Thankfully, I cannot spot any wear on the cam lobe.

Moe

[Benz Dr.]

That thrust piece is made from very hard metal so I doubt it will be damaged. The top of the valve stem is also very hard so not much chance that it will be damaged either.  The valve spring retainer is also made from hard metal so it becomes hard to determine why the thrust washer has become dislodged.

I have seen where the valve keepers became loose and a valve actually dropped into a cylinder. The engine made a fairly loud tapping noise yet the cam lobes and valve lash were in order. The top of the valve stem should sit at a predetermined height so you might want to remove several other thrust pieces to compare dimensions. If the valve stem is sitting much lower on the one you show in your picture that should be where you might want to start.

[baon3h]

Thanks for the advice! I was able to hammer the thrust piece back into place. It rotates, but not as freely as others. I turned it 180 degrees in the hope that this prevents it from getting dislodged again.

The spring holding the rocker arm down was loose. It was either not attached correctly or it's just worn out.

[Benz Dr.]

That thrust piece is designed to allow the valve to spin with the rotator under the valve springs. The thrust piece spins on the end of the valve stem.

I would look very closely at the end of the valve stem as it sits in the cone. If the valve stem keepers are worn out it will probably sit lower than it should. The thrust piece should never rub on the cone and should only touch the end of the valve stem.  Look at the recess on the cone where the thrust piece sits and see if there are any wear marks. Something is not right in there and you might need to look further.

If you hear a constant ticking sound that's a pretty good sign even though the valve lash is set right.