Catch Can M276
Trending Topics
Subsequently I looked into why we MB owners weren't hearing of or having these failures that were so common on other DI cars, and here are the 2 things I came away with: the MB DI is centered in cylinder top and actually can inject fuel on the back side of the intake valve. And 2nd: the PCV system is far more sophisticated than other makers, using better liquid knock down so the oil doesn't get into the PCV stream as easily.
My dealer stopped recommending the BG treatment after that 1st year. I found that this problem was pretty significant on Ford Ecoboost engines (another close-as-can-be turbo to exhaust stream design). Ford, for a long time, has denied warranty to any engine that has shown to have had any sort of upstream cleaning done to it. Why? Because they did it themselves and found the turbos were either immediately failing or failing within a thousand miles.
The solution for many DI cars is a catch can. But the real solution is a dual injection system, that first Toyota and then Ford and others have gone to (clean the intake valves the old way, with fuel). But Mercedes didn't follow until very recently - my assumption is that since they had the most experience with DI, their implementation was simply "better" and this issue isn't very common. The picture above is not a very dirty intake valve(s). Look around the internet and see some really bad build-up, that does affect performance...
I'm not installing a catch can on my M278, but I am on another vehicle with a different DI set-up (which is known to have significant potential issues).
Not trying to bash anyone for doing a catch can at all. Just saying that if this was an issue for us, we'd know about it, and FOR SURE there'd be lots of aftermarket implementations/offerings for our engines...
My $.02 and let's keep this discussion going - I'm here to learn...
The Best of Mercedes & AMG
Subsequently I looked into why we MB owners weren't hearing of or having these failures that were so common on other DI cars, and here are the 2 things I came away with: the MB DI is centered in cylinder top and actually can inject fuel on the back side of the intake valve. And 2nd: the PCV system is far more sophisticated than other makers, using better liquid knock down so the oil doesn't get into the PCV stream as easily.
My dealer stopped recommending the BG treatment after that 1st year. I found that this problem was pretty significant on Ford Ecoboost engines (another close-as-can-be turbo to exhaust stream design). Ford, for a long time, has denied warranty to any engine that has shown to have had any sort of upstream cleaning done to it. Why? Because they did it themselves and found the turbos were either immediately failing or failing within a thousand miles.
The solution for many DI cars is a catch can. But the real solution is a dual injection system, that first Toyota and then Ford and others have gone to (clean the intake valves the old way, with fuel). But Mercedes didn't follow until very recently - my assumption is that since they had the most experience with DI, their implementation was simply "better" and this issue isn't very common. The picture above is not a very dirty intake valve(s). Look around the internet and see some really bad build-up, that does affect performance...
I'm not installing a catch can on my M278, but I am on another vehicle with a different DI set-up (which is known to have significant potential issues).
Not trying to bash anyone for doing a catch can at all. Just saying that if this was an issue for us, we'd know about it, and FOR SURE there'd be lots of aftermarket implementations/offerings for our engines...
My $.02 and let's keep this discussion going - I'm here to learn...
That's my take on it, you read any forum with DI motors of the past 6+ years and they all seem to have the issue. That's why I find it curious we never hear about it on our cars and MB stuck with single DI injection for so long? Must happen, or why are they too going to dual injection...?




Last edited by Darel; Mar 9, 2020 at 08:21 AM. Reason: add pic




