There are 1 owner-reported engine complaints for the 2015 Mercedes-Benz S-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
Cylinder wall 2 and 3 scorn horribly. Coolant leaking into cylinder 2 & 3. Dealer recommendation of new motor due to bad block. German Auto Works and CarStoreUSA Wichita KS both recommend new motor and have advised of many of same motors being recalled by Mercedes Benz. I also spoke with Mercedes Benz North America. The heads were replaced in 2022 already and have under 10k miles on motor since repair.
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