Mercedes-Benz E350 thumping noise upon acceleration, worsens in higher gears on Mercedes-Benz E350

Some Mercedes-Benz E350 owners report experiencing a thumping noise during acceleration that worsens in higher gears, which may be attributed to several potential causes. These issues can stem from overadvanced ignition timing, particularly between 2000 and 4000 rpm. Additionally, a clunking noise may be heard during throttle lift-off or when shifting between forward and reverse, possibly indicating a problem with the side shaft. Owners also note thumping or clunking sounds from the middle or rear of the vehicle during acceleration and turning, which could be related to worn-out struts, shocks, CV joints, or ball joints. Furthermore, some owners have observed that the noise may occur when the transmission shifts down into first gear. To resolve these concerns, it is advisable for owners to have the ignition timing checked, inspect the side shaft, and assess suspension components for wear, as well as monitor transmission behavior to ensure proper function. Consulting a professional mechanic is recommended for effective diagnosis and resolution of the thumping noise issue.