jere.o988

Hello guys I got a 2014 GLK250 with almost 190k miles. I’ve noticed my car surges really bad and shakes really bad between the 1000-2000 rpm rage (doesn’t matter if I’m in Park, Drive, Neutral, or Reverse). Which is usually when the turbos aren’t making any boost. Which makes me believe I got a boost leak somewhere in the system. But I’ve also noticed my waste gate on my bigger turbo that keeps opening and closing non stop (I can’t see the smaller turbo since it’s under the air box), and I can hear a constant pssst sound exactly where the vacuum reservoir is located. Which synchronizes with the waste gate opening and closing. WHICH makes me believe my vacuum reservoir might starting to fail. I have no CEL and when I connect my FoxWell scanner with Mercedes software it doesn’t read anything out of the ordinary. So what could it be? A boost leak somewhere or a vacuum leak? Possibly my vacuum reservoir is starting to fail?

The symptoms:

I’m having is surging between 1000-2000RPM when there’s zero boost. Anything past 2000 it stops surging. Unless if I stop accelerating and I try to accelerate then it surges (right when I hear my blow off valve release all the boost pressure)

The waste gate on turbo keeps opening and closing non stop and I can feel the car accelerating and de accelerating due to this issue.

A constant psst sound coming form vacuum reservoir tank that synchronizes with turbo waste gate opening and closing.

I don’t have a CEL so I can’t give you any codes.

andreigbs

Does sound like a cracked plastic vacuum tank.