I noticed this black oil leaking out of the middle of the aluminum intake. The photos were taken from the driver's side and then the passenger side of the intake, next to the diesel filter.

 

I wiped everything clean and it has not leaked again even with the a/c on. The leakage is right in the middle of the intake, between the 3 and 3 long aluminum runners into the engine. The liquid is oily, greenish black. For engine oil I use Mobil fully synthetic 0W40 as recommended by MB Canada. However, the location of the leak suggests that it may be diesel fuel or some other stuff.

 

I'd bet it's the oil vapors of the crankcase vent seeping past the gaskets.

 

240:

Thanks for the quick reply. After removing the plastic cover on the driver's side there is this large aluminum chamber with 7 pipes. 6 of them go across to the engine as the intake manifold and in the middle of all these pipes is a 7th pipe that goes vertically down with an O ring type connection and that is where it was leaking.

There are 2 screws holding this connection together. I wonder if leaving the plastic cover off cools the intake and stops the leak.

If the leak is indeed the vent pipe as you suggested is this a major fault? Is this a common thing in MB diesels or is my car a lemon? Should I take this back to MB? I do not want them to do major surgery on my car if it is an unimportant fault.

My 20 year old 560 SEL leaked oil all the time and I was not worried. My wife was and she convinced me it is good for my health to get rid of that car.

 

It's a brand new car. If there is a defect in it, the dealer should fix it.