Engine complaints by model year
| Year | Complaints | Share of year's complaints | Typical mileage |
|---|---|---|---|
| 2024 | 3 | 21% | — |
| 2023 | 2 | 9% | 4,000 miles |
| 2022 | 2 | 8% | — |
| 2021 | 8 | 53% | 88,000 miles |
| 2020 | 8 | 24% | 100,000 miles |
| 2019 | 17 | 25% | 6,000 miles |
| 2018 | 37 | 33% | 54,000 miles |
| 2017 | 79 | 37% | 48,000 miles |
| 2016 | 94 | 33% | 29,000 miles |
| 2015 | 128 | 34% | 53,000 miles |
| 2014 | 2 | 2% | — |
| 2013 | 8 | 3% | 90,000 miles |
| 2012 | 5 | 2% | 53,000 miles |
| 2011 | 11 | 2% | 50,000 miles |
| 2010 | 13 | 3% | 70,000 miles |
| 2009 | 22 | 4% | 76,000 miles |
| 2008 | 34 | 5% | 80,000 miles |
Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
What owners report
I had to take a detour one night coming home, the detour led to a bridge that connects to a highway. Approaching the bridge my car started to jerk and pop up with all of these notification about "blind spot assistance" is down, "car engine failure, please check user manual", "car malfunction" with a engine battery symbol. All the while the engine light was on. All these warning was popping up one after another, while I was trying to merge onto the bridge. Mind you there is no shoulder currently during the active merging or on the bridge, but I didn't think of what would happen next. As I merge onto the bridge at 35mph the car shuts off completely on me. My car automatically sets itself into Neutral mode and I was rolling on the bridge at 35mph, no shoulder and no brakes or gas to move properly. …
On Friday [redacted] at approximately [redacted]. My wife and I were driving our 2024 C-Class 300 (~8,000 miles on this vehicle) on [redacted] and entering the intersection of [redacted]. Riverside, CA 92506 when all of sudden the car just died (the engine stopped running, pushing the gas pedal with no power) and all the dashboard lights came on flashing like crazy. This incident paced my wife and I in a very venerable bad not safe situation. If there was any traffic at in this intersection at that moment it would have been a bad situation. I called MB Walter's they could hear the sounds which were loud and they ask me to open and close the doors to see if sound would stop and wait 5 minutes and try to restart. Waited 5 minutes car started and we drove it to Walter's. The week before I had it back in the service department because the finger print function was not working any longer. …
The contact owns a 2021 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the vehicle stalled and failed to exceed 30 MPH, with the check engine warning light illuminated. The vehicle did not require a restart. The contact also stated that while stopped at a traffic light, the vehicle was shaking abnormally. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that there was a misfire in cylinder #2. The contact was informed that the cylinder head needed to be replaced. The vehicle was not repaired. The vehicle was then taken to the dealer, where the same diagnostic information was provided, and the contact was informed that the cylinder head needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 86,078.
The contact owns a 2021 Mercedes-Benz C 300. The contact stated that while depressing the accelerator pedal, there was a loud knocking sound coming from the engine compartment while accelerating. There were no warning lights illuminated. The vehicle was taken to the dealer to be diagnosed, and it was determined that the spawn rod was fractured, causing engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact stated that the engine was previously repaired because of the head gasket failure in 2024. The manufacturer was informed of the issue, and a case was opened. The failure mileage was approximately 88,000.
The contact owns a 2020 Mercedes-Benz C300. The contact stated that while at a stop, the vehicle failed to accelerate as intended. There was no warning light illuminated. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 100,000.
I purchased this 2020 Mercedes-Benz C300 only two months ago and have driven it less than 3,000 miles. The Carfax report shows consistent maintenance and regular service history by prior owners. While driving, the check engine light came on and the vehicle began shaking and running roughly. Diagnostics by Peachtree Imports (10/03/2025) and later by Mercedes-Benz of Atlanta South confirmed Cylinder #2 failure on the M264 2.0L engine at only 26,589 miles. The dealer's report states: "Cylinder #2 mixture formation out of spec. Fault occurred due to worn exhaust valve seat. Cylinder head replacement required." Estimated repair cost: $10,470.66. This causes misfire, loss of power, and unsafe drivability. The failure matches Mercedes-Benz Technical Service Bulletin LI01.30-P-072328 (2021), which documents valve-seat leakage in M264 engines requiring head replacement. …
The contact owns a 2019 Mercedes-Benz C300. The contact stated that the "Service Engine Soon" warning light was illuminated. The contact restarted the vehicle several times; however, the warning light remained illuminated. The vehicle was taken to an independent mechanic who retrieved DTC code: P0600 -which was related to the secondary oil pump. The vehicle was then taken to another dealer where the contact was informed that the vehicle could be repaired at that location; however, the contact was later informed that the dealer did not have the part needed to service the vehicle and referred the contact to another dealer. The vehicle was taken to a dealer where another diagnostic test was performed, and the dealer confirmed the failure. The contact was provided an estimate for the repair but declined the repair. The vehicle was not repaired. …
The contact owns a 2019 Mercedes-Benz C300. The contact stated that while at a stoplight, there was an abnormal odor of fuel inside the vehicle. The contact stated that the vehicle failed to respond as needed. The vehicle was restarted and shut off independently. The check engine warning light was illuminated. The contact stated that the failure was related to NHTSA Campaign Number: 21V961000 (Fuel System, Gasoline). The vehicle was towed to an independent mechanic who determined that the failure was a fuel rail failure. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed there were no open recalls on the VIN. The failure mileage was approximately 60,000.
Related recalls (2)
Engine and engine cooling › Engine › Engine control module (ECU/ECM) › Software
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2010 E350, 2014 G550, 2008-2009 C300, 2008 C350, 2009 CLK550, 2007 SL550, SLK280, and 2008 SLK350 vehicles. Various control units may have been updated with incorrect software configuration during a service repair.
Remedy: Dealers will update the software configuration on the affected control units, free of charge. Owner notification letters were mailed May 3, 2022. Owners may contact MBUSA customer service at 1-800-367-6372.
Engine and engine cooling › Engine › Gasoline › Turbo/supercharger
Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2020 C300, E350, and GLC300 vehicles equipped with turbocharged 4-cylinder gasoline engines. The screws that retain the turbocharger oil feed and return lines may not have been properly tightened, possibly resulting in an oil leak.
Remedy: MBUSA will notify owners, and dealers will inspect the turbocharger oil lines and tighten them as necessary, free of charge. The recall began August 17, 2020. Owners may contact MBUSA customer service at 1-800-367-6372.
NHTSA investigations
C300 Wrist-pin allegation
In a letter dated April 29, 2022, Mr. Sergio Betancourt (the petitioner) submitted a petition attributing engine failure of his 2015 Mercedes-Benz C300 to "wrong sized wrist-pins" and asserted that these were prevalent on all Mercedes-Benz models (including the Metris minivan, GLC300, and C300) equipped with a version of the M274 engine.
Frequently asked questions
Which Mercedes-Benz C300 years have engine problems?
By NHTSA complaints, the 2015 (128), 2016 (94), 2017 (79), 2018 (37) and 2008 (34) model years. Engine complaints make up 34% of all complaints for the 2015.
Is there a recall for Mercedes-Benz C300 engine problems?
Yes — 2 recalls, including 22V-168 (software, Mar 18, 2022); 20V-364 (turbo/supercharger, Jun 22, 2020). Recall repairs are free at authorized dealers; check a specific car with the VIN recall check.
At what mileage do Mercedes-Benz C300 engine problems start?
Across all years, half of the complaints with a recorded mileage happened before about 60,000 miles; 34% happened before 50,000 miles.
What part fails most often?
Owners most often name the cooling system (2 mentions), followed by the exhaust system (2).
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.