Try running a can of injector clearner in your next tank of gas, That my help!

Did some checking and the timeing chain tensioner has an O-ring. After a few years the O-ring get's hard and starts leaaking, i'm going to put a new tensioner in and it comes with a new O-ring. I will let you know if this stop's my leak!

Mine is leaking in the same spot, i have an 05. i don't think it's the valve cover, i think it's the front timeing cover gasket. the plug you refured to is the timeing chain tensioner. i thought it might be comming from that. i tried to tighten the bolts on the tensioner but they were not loose i'm ...