under w202 rocker cover

[japimport]

i took my rocker cover off toay, to see if i could tighten the head up, as i have a oil gasket leak just above the timing chain tensioner,i noticed some part of the camshafts was brownish and the rest looked ok,im just wondering what it could be from, i have some pics

 

[BlackC55]

It is engine oil staining. It is no problem.