OM603 Lifters

[treetops]

I took off the valve cover to check the tappets/lifters and timing chain. The basic test with a wooden rod showed the tappets on cyls 1-3 were bad and could be pushed easily. The ones on 4-6 were stiff which means good.

I wonder if this means something more than just bad lifters and may point to something else.

About three months ago I changed the oil and overfilled it by a 1.5 qts. I drained and refilled to the right amount pretty quickly(30 miles or so). It was then that I noticed the characteristic tick tick ticking of the tappets. Could I have caused some damage oil wise that may be the culprit for these tappets going bad or do they go bad in groups like this. (I thought some would and some would not, but not all in a group like this)

Thanks for the thoughts in advance.