Head gasket???

[bleverman]

Working on my 87 560SL and just got my intake manifold off and noticed coolant in cylinder no 4. Is this a bad head gasket or due to the intake manifold gasket being bad? I was really surprised because I hadn't noticed any smoke coming out the back and it was running pretty smooth except for the high idle issue. I'm just a hobby mechanic and felt comfortable with the intake manifold but I'm not sure I want to take the head off. I'm definitely not going to rebuild it! Thoughts or suggestions? The yellow arrows in my picture show where the coolant is.