So I have a 2014 ML350 Bluetec 4MATIC. I noticed this morning that the check engine light was on so I go to Autozone to have it scanned it came back with a MAF sensor. The thing is I realized I should be changing my engine air filters alot more than normal as the road I work off of is HORRID. Didnt even cross my mind until that engine scan. But its running fine so lets just get to work and get home and we'll get it done. Well shortly after I left I noticed I was at about 75 MPH and I noticed that I couldn't accelerate at all. No noise, its not in limp mode I can maintain speed. Its just not going past 75 MPH. Its like its put a block on itself from going past Gear 6 at about 2250 RPMs. Is this due to the engine not getting enough air? Does the engine thinks its choking from lack of air flow? Taking it to auto zone to buy air filters and get it scanned again while im there but has anyone soon this or encountered this? I did take a quick peek into the engine bay and noticed oil on the housing of the alternator but I just got an oil change so I just put that down to someone spilling a little bit of oil down there but it was enough to catch my attention.

 

Did you get anywhere with this? I have a 2014 ML350 Bluetec as well, did the exact same thing you describe. Mine was throwing the MAF code CEL as well. I brought it to my mechanic, they replaced the MAF ($800 for the part, and a diagnostic/ install fee), which fixed it for about 2 days, then the MAF code and light came on again.

Did you already have the emission modification done? Maybe there is some issue there with the ECU/ codes?

 

Check out this post, looks like you might have a busted hose. I'm going to check mine later today/ tomorrow.

https://mbworld.org/forums/glk-class...1-p0299-3.html