[gr_diver]

Today while adjusting valve-lash (solids) I remembered reading on web site a while ago that rocker arms can get deformed at the point where they touch the valve stems, forming a small "cup", that could make adjustment seem OK to the feeler blade (as it is wider than the stem), but in fact be off the spec... Has anybody come across such a condition in an Opel engine?


This of course does not affect hydraulic lifters due to the nature if their adjustment...

 

[GTJIM (R.I.P.)]

Yep!

On really high milage motors the valve stem tip does wear its way into the contact surface of the rocker face. This does leave a "step" which can be bridged by a feeler gauge. The "cure" is to use motorcycle type feeler gauges with the tapered narrow end that is only as wide as the valve stem tip .....
Never grind the rocker tip flat again or you will break through the case hardening and the rockers will be scrap ......

 

[gr_diver]

You are absolutely right! Now that you mention it, there was a recommendation on the same site to cut the edge of the feeler in a "T" like shape...

Next time I'll better check it, as my engine has seen over 100.000km...