My 2008 GL 320 had an exhaust leak and we originally thought it was the seal at the turbo

but when They started taking the motor apart it really smelled it around the injectors, pulled off those black foam cushions and I had one injector on each side with carbon buildup from the injector seals leaking

This is a big problem on 05 and 06E320 inline Motor but I had no idea the V6 did it also

In fact the injector bolts and seals are the same ones as the 05/06 E320 cdi

I had noticed a little slight rough running every once in a while Andthought maybe it was motor mounts but now I am sure it was this

From now on every time my air filters are changed that will come apart to check for injector leaks

My suggestion is if you have a slight rough idle, miles per gallon seems down a little bit etc. check the injector seals, because they are so buried in there hoping a lot of us don't have small leaks around the injectors and don't realize it

My mercedes dealer had all the parts and my parts guy said they see the seals leaking on quite a few higher mileage sprinter vans with the V6

The good thing is this is a relatively easy and cheap repair if caught early, , but becomes a bigger pain in the *** if the injectors get badly carboned up and can get costly

So my suggestion is to put this on your maintenance checklist