when i was going home the other day i noticed that i had a "tap-tap-tap" sound coming from the top end. i couldnt see the source of the problem initially, but i noticed that the tensioner was down to ~1-2mm so i ordered a new cam chain.
went to go fit it, and one of my inlet rocker arms looks like this...
![Image](http://img.photobucket.com/albums/v633/Banner001/2013-05-16082811_zps67af759e.jpg)
![Image](http://img.photobucket.com/albums/v633/Banner001/2013-05-16082740_zpscc23ff23.jpg)
what would cause it to wear in that place?
the camshaft seems fine and there is plenty of oil in the cylinder head, on the camshafts, and on the bearing surfaces so i dont think its an oil problem.
im going to replace the rocker arm, and ive read that a slack valve spring can cause this to happen by allowing the valve to "bounce" the rocker arm, if that makes any sense, so ill change the valve spring if anyone thinks thats a valid thing to do?