When I pulled the engine cover off the other day I noticed a couple things here. Does this look like an oil leak from the valve cover and should I be concerned about the missing screw roughly in the center of the photo? I'm not sure what that part is but it looks to be an engine support or something like that.

I think the missing screw could be from the dealer's servicing of the obligatory cam adjuster failure.

 

You are missing two screws actually. One on the engine lift and one to the right......

 

Your cam magnet seal is leaking. Buy new O-rings and replace or replace the whole magnet/sensor. Will take you about 15 minutes to change that one.

For sure you have a bolt missing on the left that holds that bracket to the engine.

 

I guess this one isn't critical but missing screws does not give me confidence in the dealer workshops.

What would the screw in the center be for? I see nothing around there that looks like it would need one?

Thank's for the tip on the o-ring. Could the leak have been caused by the cam adjuster job?

 

That cam adjuster/magnet doesn't look like it has been touch or removed in quite a while. Is your repair shop going to be shown this ?

 

The prior cam tensioner failed about a year and a half ago, somewhere between 25-30K miles. I just crossed over 60K now so it has been a while.

I'd be hesitant to bring my car back to any Mercedes dealership ever again.

 

If the dealer has been generally OK, I wouldn't dismiss any MB dealer for a missing bolt.
I used an indy recently and later found a flashlight lying on the front apron when I raised the hood to check the work.

Life happens everywhere!!!!

 

Oh, that's not the reason I wouldn't go back. I've found some good tools under the hoods of cars too.

But after countless issues I've had it makes me worried about sloppy work in general. That's just what I can see. Warranty work or not the dealer service shops charge a hefty fee.

I usually try to inspect most work when I can. The worst thing I've found was a shop didn't reattach my axle bolts. But that was a different car.