Continued....
4. I noticed on the intake side port on cylinder #5 has some strange thing going on it appears that there is some oily residue splattered around the port as oppose to the other ports that has even soot build around. Question is could a leaking valve stem seal cause this? Or is it a result of a leaky valve or off timing may be causing some backflow (regugration)?
Cylinder #5 intake port (problem intake port)
All other Cylinder intake port (similar approximation)
Other then that I think its a straight forward job but these hurdles are make it a little more nerve wrecking as I want to have no mistakes, your input will be gladly appreciated
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Current Garage
2008 Mercedes GL320 CDI 188k mi Repair/Work in progress
1994 S350 160k mi Garage Queen & prepping for repairs
2005 E320 CDI 203k mi Healthy & Daily Driver
1994 S350 357k mi Retried as parts car
1984 300TD 214k mi Blown OM617 Poss OM603 Swap??
Sold
1987 300SDL 200K+
1994 S320 181K mi
2008 E320 Bluetec 127k mi
1999 S420 130K mi
1980 240D 360k mi
15+ Others that has come, stay and gone
GONE, BUT NOT FORGOTTEN 
1995 E320 SE 220k mi
1984 300SD 350k mi