I realize this question was asked nearly 2 yrs ago, but for someone else's benefit, Ill add suggestions. The symptom of shuddering during acceleration can be caused by several things: Mass Air Flow sensor; air escaping the charge air system (follow the plumbing from the turbo through the aluminum pipe down the front through the intercooler on the right side, out the intercooler on the passenger side and up into the air intake looking for oily areas where pressurized air may be escaping. On the exhaust side, a gasket in the manifold, turbo, or further back in the catalyst or DPF may also be contributing. Also, on the DPF, there is a pressure differential sensor. Also, EGR valve, EGR cooler, EGR plumbing and finally air intake may be coked up with carbon - if that is the case, you need to remove both air intakes (painful job) and clean them - while at it, replace the the butterfly valve connectors with aluminum connectors from the internet and be done with the plastic ones, and the motor that connects them. Further, the turbo actuator may have failed - without more sophisticated Mercedes-specific diagnostic equipment, this is a very difficult condition to diagnose, but you and a friend can generally rev the engine to around 2k rpm and look for leaks and sprays.
Answers & Comments
I realize this question was asked nearly 2 yrs ago, but for someone else's benefit, Ill add suggestions. The symptom of shuddering during acceleration can be caused by several things: Mass Air Flow sensor; air escaping the charge air system (follow the plumbing from the turbo through the aluminum pipe down the front through the intercooler on the right side, out the intercooler on the passenger side and up into the air intake looking for oily areas where pressurized air may be escaping. On the exhaust side, a gasket in the manifold, turbo, or further back in the catalyst or DPF may also be contributing. Also, on the DPF, there is a pressure differential sensor. Also, EGR valve, EGR cooler, EGR plumbing and finally air intake may be coked up with carbon - if that is the case, you need to remove both air intakes (painful job) and clean them - while at it, replace the the butterfly valve connectors with aluminum connectors from the internet and be done with the plastic ones, and the motor that connects them. Further, the turbo actuator may have failed - without more sophisticated Mercedes-specific diagnostic equipment, this is a very difficult condition to diagnose, but you and a friend can generally rev the engine to around 2k rpm and look for leaks and sprays.