There are 3 stored owner reports matching the engine leading-label group for the 2021 Mercedes-Benz E-Class in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 3 of 3 matching reports.
Open the full vehicle complaint log (all categories)Engine keeps having a misfire that Mercedes put a TSB out for and once the misfire happen I cause the vehicle to go in a limp mode which causes the vehicle to loose power happened to me in the freeway. The car had 54K miles and Mercedes refused to repair the issue as the engine part failure isn’t common.
My 2021 Mercedes-Benz E350 (VIN [XXX] ) developed a serious engine issue involving cylinder misfire and check engine light. The dealer diagnosed it as a leaking exhaust valve on cylinder 4, related to TSB LI01.30-P-072328, which documents valve seat wear in M260 engines. This is a known defect acknowledged by Mercedes in technical bulletins, and other customers in the U.S. have received warranty extensions or goodwill coverage. I was denied coverage even though this is a manufacturer defect that can lead to misfire, power loss, and potential stalling, posing a safety risk on the road. Mercedes-Benz USA refuses to cover the repair (~$7,600+), even though it relates to a factory-documented problem. I’m requesting that NHTSA investigate this engine defect, as it may qualify for a safety recall or mandatory extended warranty coverage. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The 48 volt battery on this mild hybrid vehicle failed and the car was unable to be started on May 3, 2021, with 196 miles on the odometer, a mere 15 days after delivery. It had to be taken by flatbed to the dealer where ultimately the 48 volt battery was replaced. Then again on June 5, 2021, the car was again unable to be started, with a mere 735 miles on the odometer. Again, the car had to be taken by flatbed to the dealer, where ultimately the 48 volt battery was replaced a second time. While both failures, fortunately, happened while the vehicle was at home, the could have happened on the highway, in the middle of nowhere in bad weather conditions, or anywhere. I have had to cancel a cross-country drive for fear that, once again, the 48 volt battery will fail, leaving us stranded anywhere or, worse yet, in the middle of a highway.
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.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Aug 31, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.