There are 2 owner-reported engine complaints for the 2012 Mercedes-Benz S-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
ENGINE HAS OIL LEAK SIMILAR TO MANY 2011-2012 DIESEL MODEL.
THERE IS AN PLASTIC PLUG IN THE OIL SYSTEM THAT LEAKS OIL FROM THE ENGINE ON TO THE EXHAUST MANIFOLD. THIS WAS REPORTED BECAUSE OF INCREASED OIL CONSUMPTION, VAPOR IN THE ENGINE SPACE AND A SMELL OF BURNED OIL. THE PLASTIC PLUG IS KNOWN TO LEAK AND MERCEDES DOES NOTHING ABOUT THIS DURING WARRANTY AND INSTEAD WAITS UNTIL THE VEHICULAR IS OUT OF WARRANTY CAUSING AN INCREASED TIME FOR A FIRE POTENTIAL. THIS CAR IS DRIVEN ON CITY STREETS AND HIGHWAYS WITH THIS FIRE POTENTIAL.
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