There are 6 owner-reported engine complaints for the 2003 Mercedes-Benz ML-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
ENGINE KEEPS GETTING OVER-HEATED EVEN AFTER A NEW ENGINE FAN HAS BEEN REPLACED. HOWEVER, AFTER ITS REPLACEMENT I TOOK IT TO TWO MERCEDES DEALERSHIP TO RE-INSPECT AND MAKE ADJUSTMENT TO THEIR INSTALLMENT OF THE FAN BUT IT KEEPS GETTING OVERHEATED. I ALSO HAD A NEW WATER COOLANT TANK INSTALLED BUT IT IS ALSO LEAKING OUT THE COOLANT AND SHOWING THE WARNING LIGHT. THESE EVENTS HAPPEN AFTER I TOP UP THE COOLANT TANK AND DRIVE AROUND 50 MILES, THEN THE OVERHEATING STARTS AND THE TANK STARTS BECOMING EMPTY.
NOTES TAKEN ON PHONE BY BOWMAN, ODI, NHTSA: VEHICLE SHUTS OFF AFTER IMPACT WITH IRREGULAR ROAD SURFACES CONDITION SUCH AS POTHOLE, TRANSVERSING A CHANGE ROAD GRADES / SURFACES SUCH AS SPEED BUMPS, ETAL. VEHICLE CAN BE IMMEDIATELY RESTARTED AFTER SHUT-OFF. ONE INCIDENT ALLEGEDLY OCCURRED WHEN ATTEMPTING TO MERGING ONTO INTERSTATE.
AFTER CHANGING THE SERPENTINE BELT, I HAVE NOTICED THAT THE CRANKSHAFT PULLEY WAS WOBBLING AND THE BELT VIBRATING, I BEEN DOING SOME RESEARCH AND FOUND THAT THERE HAS BEEN A RECALLED FOR THIS ISSUE, DOSE MINE STILL APPLIED TO THIS PROBLEM? IT IS ALREADY OUT OF WARRANTY BUT THIS KIND OF REPAIR IS EXPENSIVE, PLEASE. *TR
I OWN A MERCEDES ML 350 2003; WHILE DRIVING THE CAR TO WORK THIS MORNING THE CAR STOPPED ACCELERATING, BECAME DISABLED AND STEERING, BECAME IMPOSSIBLE. THE CAR SLOWED ON ITS OWN WHILE I WAS IN TRAFFIC ON A MAJOR ROAD WITH SPEED LIMITS UP TO 40 MPH AND I WAS UNABLE TO MOVE THE CAR INTO THE SHOULDER CREATING A MAJOR SAFETY ISSUE. EVENTUALLY THE CAR COASTED ONTO THE SHOULDER AND ALL LIGHTS BECAME ILLUMINATED ON THE DASHBOARD. UPON HAVING IT TOWED TO MERCEDES BENZ I WAS TOLD THAT IT WAS INITIALLY A KEY FAILURE IN WHICH COMMUNICATION BETWEEN THE KEY AND THE COMPUTER IN THE CAR COULD BE LOST WHICH WOULD RESULT IN A LOSS OF POWER TO THE VEHICLE. AFTER MY REACTION WHICH WAS "AND YOU GUYS ARE COMFORTABLE WITH THAT" I WAS TOLD THAT INSTEAD IT WAS THE CRANK SHAFT SENSOR. CURRENTLY MERCEDES HAS A RECALL PENDING OR BEING CONSIDERED ON ONE OF THERE 2007 MODELS FOR THE SAME PROBLEM, BUT THIS WAS NOT COVERED UNDER WARRANTY AND IS NOT CURRENTLY A RECALL, BUT SHOULD BE. THERE ARE NUMEROUS COMPLAINTS ON THE WEB REGARDING THIS ISSUE. *TR
DT*: THE CONTACT STATED WHILE DRIVING 50MPH THERE WAS A NOISE COMING FROM THE ENGINE. THE POWER STEERING WENT OUT PREVENTING THE VEHICLE FROM TURNING. AFTER THE VEHICLE WAS PULLED OFF THE ROAD SIDE A WARNING LIGHT ILLUMINATED ON THE DASH. THE VEHICLE WAS TOWED TO A DEALERSHIP WERE IT IS CURRENTLY BEING INSPECTED.
I WAS PULLING INTO A PARKING SPACE (WITH MY 3 SMALL CHILDREN STRAPPED IN THE BACK), WHEN I REALIZED THAT THE CAR WAS NOT STOPPING. I PRESSED THE BRAKE HARDER, THE CAR ACCELERATED, JUMPED THE CEMENT MEDIAN, AND HIT A PARKED CAR. THANK GOD NO ONE WAS INJURED. I AM SICK THINKING WHAT COULD OF HAPPENED. THE CAR IS 6 MONTHS OLD AND HAS BEEN BACK TO THE DEALERSHIP TWICE FOR A PROBLEM I BELIEVE WAS THE BEGINNING OF THIS, I.E., WHEN I WOULD STEP ON THE BRAKE IT WOULD GO TO STALL, BUCK FORWARD AND THEN BE OK. THE DEALERSHIP WAS UNABLE TO FIND IT OR DUPLICATE IT. I HAVE SEEN WHERE OTHER PEOPLE ARE HAVING THIS SAME PROBLEM. ALSO FOR 2003 THE MODEL IS ML 350 - MERCEDES. AGAIN THEY HAVE NOT FOUND A PROBLEM. THEY SENT THE MANUFACTURER OUT TO CHECK THE CAR AND NOTHING. I HAVE A POLICE REPORT THAT STATES THE RESPONDING POLICE OFFICER AND TOW TRUCK DRIVER CONCUR THAT THE BRAKES WERE DOWN TO THE FLOOR BOARD AND NOT ENGAGING.*JB
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 25, 2026