There are 6 owner-reported engine complaints for the 2009 Mercedes-Benz ML-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
OIL LEAKING FROM COIL COOLER, 1-2OZ OVERNIGHT ON GROUND + OIL LOSS AT SPEED.
WHILE MY WIFE WAS DRIVING OUR 2009 MERCEDES BENZ ML63, AT APPROX 65 MPH, ON THE 101 LOOP IN SCOTTSDALE AZ, SHE EXPERIENCED COMPLETE ENGINE FAILURE. THE ENGINE COMPLETELY SHUT DOWN ON HER. SHE LUCKILY WAS ABLE TO COAST OVER TWO LANES TO HER RIGHT TO AN EXIT RAMP. THE CAR CAME TO REST AT THE BOTTOM OF THE RAMP W/ NO ENGINE POWER WHATSOEVER. MY WIFE WAS PETRIFIED. THE CAR WAS TOWED FIRST TO AAA AND THEN TO SCHUMACHER EUROPEAN, LTD (A MERCEDES-BENZ DEALERSHIP) IN PHOENIX, AZ. ACCORDING TO SCHUMACHER EUROPEAN, LTD THE CAUSE OF THE ENGINE FAILURE WAS A BLOWN HEAD GASKET DUE TO BROKEN HEAD BOLTS. THE REPAIR ESTIMATE WE RECEIVED FROM SCHUMACHER WAS BETWEEN $6,000 - $25,000 DEPENDING ON THE AMOUNT OF DAMAGE DONE TO THE ENGINE. MERCEDES-BENZ USA HAS HAD A KNOWN ISSUE W/ DEFECTIVE HEAD BOLTS. THEY ISSUED TECHNICAL SERVICE BULLETINS BACK IN 2011 ADDRESSING THE ISSUE. ALSO IN 2011 A CLASS ACTION LAWSUIT WAS BROUGHT AGAINST MERCEDES-BENZ USA CLAIMING THEY WERE AWARE OF FAULTY ENGINE DEFECTS, AND WERE DOING NOTHING ABOUT THEM TO PROTECT CONSUMERS. MY WIFE & I WERE COMPLETELY UNAWARE THAT OUR SUV HAD AN ISSUE W/ DEFECTIVE HEAD BOLTS. AND WHEN THESE DEFECTIVE HEAD BOLTS BREAK, NOT ONLY CAN THEY CAUSE CATASTROPHIC ENGINE DAMAGE BUT THEY CAN CAUSE A MAJOR PUBLIC SAFETY PROBLEM. WE THOUGHT WE OWNED A SAFE CAR. BUT THE TRUTH IS OUR SAFETY, AS WELL AS THE SAFETY OF OUR DAUGHTER (NOW 5 YRS OLD), HAS BEEN IN JEOPARDY SINCE WE STARTED DRIVING THIS SUV. HOW MANY OTHER MERCEDES-BENZ DRIVERS ARE DRIVING AROUND THIS COUNTRY IN CARS & SUV'S THEY THINK ARE SAFE BUT ACTUALLY HAVE DEFECTIVE ENGINES THAT CAN FAIL AT ANY TIME? ALSO TO NOTE: MERCEDES-BENZ USA HAS AN F RATING AT THE BBB.
TL* THE CONTACT OWNS A 2009 MERCEDES BENZ ML320. WHILE DRIVING APPROXIMATELY 60 MPH, THE VEHICLE STALLED WITHOUT WARNING. THE VEHICLE RESTARTED AFTER SEVERAL ATTEMPTS. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHO STATED THAT THE CAMSHAFT POSITION SENSOR FAILED AND NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 60,000. UPDATED 4/30/15*CN THE CONSUMER ALSO STATED THE GLOW PLUG CONTROL UNIT, HEAT ELEMENT AND DOOR LOCK FAILED. UPDATED 05/07/15*JB
CHECK ENGINE LIGHT WARNING WITH CODE #20BE1B. REPAIR INDICATES NEED OF DIESEL EXHAUST FLUID (DEF) HEATER REPAIR KIT. DIESEL EXHAUST FLUID SYSTEM IS PART OF EMISSIONS SYSTEM. MB DEALERSHIP SAYS NO WARRANTY FOR REPAIR. INTERNET RESEARCH WIDESPREAD PROBLEM WITH DEF SYSTEM AROUND 50,000 MILES. *TR
LETTER FROM REGARDING NUMEROUS ISSUES AND TROUBLES HE HAS FACED SINCE THE PURCHASE OF HIS MERCEDES-BENZ VEHICLE, A 2009 ML320 BLUE TEC DIESEL ENGINE SUV; SEEKING ASSISTANCE-HE WOULD LIKE ACKNOWLEDGEMENT OF RECEIPT OF THIS COMPLAINT *TGW THE CONSUMER STATED THE FIRST PROBLEM HE ENCOUNTERED WITH THE VEHICLE WAS IN MAY OF 2010, WITHIN LESS THAN A YEAR OF PURCHASE, WHILE DRIVING, THE GAS GAUGE ALL OF A SUDDEN WENT FROM A HALF TANK OF FUEL, TO READING EMPTY, WHERE AT THAT POINT THE FUEL LIGHT ILLUMINATED. EVEN THOUGH HE KNEW THE TANK WAS NOT EMPTY, HE STOPPED TO THE GAS STATION AND RE-FUELED. HOWEVER, THE TANK CONTINUED TO READ EMPTY. ABOUT AN HOUR LATER, THE NEEDLE MOVED TO THE FULL POSITION. FOUR TO FIVE MONTHS LATER, THE CHECK ENGINE LIGHT ILLUMINATED, ALONG WITH A BLUE WARNING LIGHT. THE VEHICLE WAS TAKEN TO THE DEALER, BUT NOTHING WAS FOUND TO BE WRONG. ON ANOTHER OCCASION, THE VEHICLE LOST ACCELERATION AS THE CONSUMER WAS ATTEMPTING TO GO UPHILL ON AN INCLINE. THE VEHICLE STARTED TO SLOW DOWN IN SPEED. EVEN TRYING TO PUMP THE ACCELERATOR PEDAL DID NOT HELP AND EVENTUALLY THE VEHICLE STARTED TO STALL. THE CONSUMER EXPERIENCED THE SAME FAILURE, SEVERAL MORE TIMES AFTER THAT. THE CHECK ENGINE LIGHT ILLUMINATED SEVERAL OTHER TIMES AS WELL. THE DEALER CHANGED THE ENTIRE COMPUTER MODULE. SOON AFTER, THE TIRE PRESSURE LIGHT ILLUMINATED. ONCE THE TIRES WERE CHECKED, THE LIGHT NO LONGER APPEARED.
THE SUV SLOWS AND/OR STALLS SUDDENLY AT DIFFERENT SPEEDS. STARTED AROUND 8,000 ORIGINAL MILES ON ODOMETER. IT IS A 2009 ML 320 BLUETEC. OCCURS UNEXPECTEDLY FOR FEW SECONDS RANDOMLY. *TR
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026