E350 Valve Cover Oil Leak
 

Hi, I'm a recent purchaser of an '07 E350. The valve cover on the drivers side has developed a leak at the rear of the cover by the cam journal. My mechanic says that there is not a gasket but rather a sealant between the cover and the block. The cost of repair is about $700.00. The car has less than 35,000 miles on it and needless to say I'm a bit disappointed (warranty expired several months ago). I hope I do not have to make this repair more than once. Anyone else experiencing this type of problem? Any idea what might cause it . . . over filling with oil maybe? Insights appreciated.

Doug Nelson