I realize I'm asking my questions backwards (valve adjustment before valve guides) but I was reading through an online W116 manual and am a bit confused about the specs for valve guides (450sel). The guide IDs are given as 9.000-9.015mm for the intakes and 11.000-11.018mm for the exhausts, so does this mean .015mm/.018mm of wear is the allowable limit and anything over that should be replaced? Also, the text which goes on to say:
"Valve guides into which the not-go plug with the limit wear dimension (+220) can be inserted at one point with its full height (5mm) must be replaced."
I understand the part about using a go/no-go gauge but what does the "+220" number mean and how does it relate to the ID specs?