Mercedes-Benz C 300 2022–2024 — technical service bulletin
Bulletin LI01.00-P-078512 · NHTSA communication 11009517 · issued Oct 25, 2024
Technical service bulletin
communication type
Engine
component
2022–2024
model years
7
vehicle entries
Official summary
Complaint Engine is making abnormal noise at idle. May be described as rattle, tapping, or knocking. Cause Various Remedy If necessary compare the noise to a like vehicle and if determined to be abnormal proceed with below steps. Submit a TIPS case to the powertrain team with details from the below checks: Check engine maintenance history and oil level. Determine location where noise is most noticeable on engine. Does noise change with engine RPM? Record a video of the noise. Switch off injectors with XENTRY diagnosis one at a time and check if noise changes. Borescope cylinders with pistons a
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.