72 of the
2,855 complaints filed about the Mercedes Benz C300
are about the transmission —
3% of everything owners reported.
The worst model year for it is 2015.
72
Complaints
3%
Share of all complaints
2
Crashes
0
Fires
Transmission & Drivetrain complaints by model year
My C300 MBZ, 2016 is experiencing the same symptoms as indicated in a recall, but my vehicle is not included in that recall. Camshaft: GENERAL REPAIR A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice versa. Cams act as a vital component to your automobile's engine. A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part. Camshafts provide power to the cams which are vital for basic engine operation. The cost of fixing this approximately $10,000 per Mercerdes dealer and estimate from Keyes Mercerdes. The Brief: Mercedes-Benz issued a recall for some model cars tied to a faulty drive shaft.T he problem not only can cause vehicles to lose power but may elevate crash risk, according to the National Traffic Safety Administration. Owners of the affected vehicles can take them to their local dealership to receive free repairs, however per MBZ corporate 2016 C300 not included? Mercedes-Benz is recalling 24,092 cars connected to a drive shaft universal joint that may break, resulting in a sudden loss of drive power.
NHTSA complaint #11733625 — an unverified report by a vehicle owner.
I am reporting a structural failure of the rear subframe (axle carrier) on my 2016 Mercedes-Benz C300 (W205). The component is exhibiting significant internal-to-external corrosion (perforation), specifically at the suspension mounting points. Safety Impact: The vehicle is currently exhibiting unstable handling and a 'skittish' 'swerving' sensation causing the car to 'fishtail' under braking during normal braking and at highway speeds, indicating a compromise in the structural integrity of the rear axle. This poses an immediate risk of a 'loss of directional control' should the suspension components fully detach from the corroded subframe. The Structural Integrity, Loss of Directional Control, Sudden Suspension Failure, and causes extremely dangerous Safety Hazard for my family and other on the road. The corrosion has compromised the mounting points of the rear suspension, creating a risk that the axle will detach while the vehicle is in motion, leading to a catastrophic loss of control. Context: Mercedes-Benz has acknowledged this defect in previous years (2008-2015) via a 20-year extended warranty and in Service Information S135.00-P-0009A. However, they have failed to include the 2016 W205 in the safety remedy despite identical failure modes and documented safety hazards. Currently, as of April 2026, a 2024/2025 federal court ruling [XXX] v. Mercedes-Benz) allowed a class-action lawsuit to proceed specifically covering 2010–2022 models—including the2016 C300 W205—alleging the exact same manufacturing defect. A thorough inspection of the undercarriage of the vehicle shows severe corrosion to the subframe as well as a cracked hub along the drive-train shaft and differential. I have submitted photos along with this Vehicle Complaint From to document the corrosion of the subframe and other defects associated with the devices and systems that transmit power from the engine or propulsion device to the wheels such as the cracks in hubs, shafts, differentials. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORM
NHTSA complaint #11732985 — an unverified report by a vehicle owner.
Rear subframe completely rusted out. While driving on the hwy I heard a loud noise, a couple minutes later I hit the brakes to slow down to get off my exit and after pressing the brakes the car instantly fishtailed sending me sideways across 2 lanes of traffic. Luckily no one was injured or killed. I’ve seen that the car manufacturer was replacing this issue on models 2008-2015. My vehicle is a 2015 and they are telling me my vehicle is not covered for the issue. The car is not drivable and Mercedes needs to be held accountable. A critical component such as rear subframe completely rusting out in just under 10 years is unheard of and I can’t afford to pay 10k to fix it. Please help
NHTSA complaint #11696650 — an unverified report by a vehicle owner.
Rear-subframe corrosion at the lower-control-arm mounts has progressed to the point where both arms have play and produce loud metallic bangs while braking or turning at low speed. Two independent shops lifted the car, documented flaking rust around the bushing sleeves, and advised the subframe is structurally compromised and could let a control arm detach under load. The corroded subframe remains installed and can be inspected on request. Safety risk: a detached rear control arm would cause sudden, unpredictable steering and loss of control. The vehicle already pulls right under braking, and feels very unstable in curves Problem has been reproduced and photographed by two independent repair facilities. No manufacturer representative has inspected the vehicle so far. Additional component failures possibly linked to the same progressive chassis stress: premature wear of both front CV axles; timing-chain stretch with worn guides; slack oil-pump chain; upper & lower oil-pan gasket leaks; water-pump seepage; right engine-mount collapse; persistent misfire traced to a loose intake-hose clamp; transmission-cooler hose clip released under pressure, dumping all ATF and destroying the automatic transmission; excessive play in all four lower control-arm bushings. The transmission and the other components were replaced 1-2 months before the subframe bro History: A faint clank from the rear suspension first appeared roughly three years into ownership. Dealer service dismissed it as “normal noise,” and warranty would not cover “loud clanks,” so the issue went unaddressed. The noise has grown steadily into the current condition, suggesting long-term subframe corrosion that was never inspected or remediated. No collision, flood, or off-road use; the car has typical Northeast winter-salt exposure. The failure pattern matches subframe-corrosion cases already acknowledged by the manufacturer on this model, although this serial number is not yet included in the official campaign.
NHTSA complaint #11663816 — an unverified report by a vehicle owner.
I own a 2016 Mercedes Benz c300 4matic 44,000 miles and i started my car to pick my girlfriend up and 3-5 mins into the drive my check engine light popped up i went to get it scanned and code “P052E” came back, I did some research about the part and i come across a forum called MBworld and many others are having this same problem. I ask for a recall.
NHTSA complaint #11645144 — an unverified report by a vehicle owner.
failed piston wrist pins from early production of mercedes w205 c300. The issue was diagnosed by mercedes of manhattan and could not provide me a fix. Stated that the issue is common with the vehicle and it does not warrant a recall for this issue. i believe its a safety issue and my vehicle only has 60K miles
NHTSA complaint #11639535 — an unverified report by a vehicle owner.
Purchased vehicle in march 2024 it went thru emission inspection in 2022 after failing it passed second time . I go for inspection and it fails emission test again just passed two years later. After doing my research Positive Crankcase Ventilation System seems to be a very common problem. It also cost 2000 to fix. Appreciate you time thank you
NHTSA complaint #11607201 — an unverified report by a vehicle owner.
The Positive Crankcase Ventilation (PCV) valve is crucial for regulating the flow of gases in the engine's crankcase. If the PCV valve malfunctions or becomes clogged in a car like the 2016 Mercedes Benz C300 4-matic, several problems can arise: 1. **Increased Pressure:** A malfunctioning PCV valve can cause pressure to build up in the crankcase. This increased pressure can lead to oil leaks, gasket failures, or even engine seals blowing out. 2. **Poor Engine Performance:** When the PCV valve fails, it can disrupt the air-fuel mixture in the engine, leading to rough idling, stalling, or decreased fuel efficiency. This can result in a loss of power and overall poor engine performance. 3. **Contamination:** A faulty PCV valve may not properly route harmful gases, like unburned fuel and moisture, out of the crankcase. This can lead to contamination of the engine oil, reducing its effectiveness in lubricating engine components and potentially causing premature wear and damage. 4. **Increased Emissions:** A malfunctioning PCV valve can result in increased emissions from the vehicle, as it may not properly recirculate harmful gases back into the combustion chamber for burning. Overall, a nonfunctional PCV valve can negatively impact both the car's performance and the environment, potentially leading to costly repairs and increased pollution. Additionally, prolonged exposure to increased emissions from the vehicle can be harmful to both the environment and the health of individuals. Therefore, it's essential to regularly inspect and maintain the PCV valve to ensure proper functioning of the vehicle.
NHTSA complaint #11579368 — an unverified report by a vehicle owner.
Power Train System - P052E Positive Crankcase Ventilation Regulator Valve Indicates a fault in the Positive Crankcase Ventilation Regulator Valve. I repaired my car for the same issue in 2019 January and it failed again in 2024 January. It costs $2000 to repair and it has a warranty of two. It failed after 3 years. Same issue is occurring in Mercedes C300 and GLC 300 and multiple times. But company isnt taking any responsibility to fix the issue or at least extend the warranty. 1. Incident 1 - Jan 2019, Miles 28k 2. Incident 2 - Jan 2024, Miles 61k
NHTSA complaint #11567582 — an unverified report by a vehicle owner.
The ESP®, or Electronic Stability Control system can put the car into limp mode unexpectedly. Say you are driving on route 66 going 50 mph. The ESP system can turn off if a wheel speed sensor or yaw sensor is on the way out. This causes the car to suddenly dramatically brake and limit speed to 5 mph on the highway. Risk of high speed rear end collision and mortality to the driver.
NHTSA complaint #11561434 — an unverified report by a vehicle owner.
Started smelling gas then check engine light came on took it to mercedes they did diagnostic which said low boost and that I needed to replace the turbocharger at a cost of over $7000
NHTSA complaint #11542440 — an unverified report by a vehicle owner.
Check engine light comes up. The crankcase ventilation has to be replaced. This is a well known defect in design by Mercedes Benz and there are hundreds of people who have had to replaced the crank case costing thousands of dollar to only have it happen again due to its faulty design. It’s well documented all over the Internet.
NHTSA complaint #11537572 — an unverified report by a vehicle owner.
My car is the 2015 Mercedes- benz (MB) c 300 4MATIC. The Check engine light is on and off for some months as initially MB dealer said that it's likely due to gas cap defects so we replaced the gas cap. After that, the engine light is still on and off. MB dealer now said $1,760 to replace crankcase vent value and $2870.55 to repair the front differential leaking/reseal. It will cost me a total of $ 4630.55 +tax to repair. The car has only 70,000 miles and kept good maintenance frequently. Right now my car is not safe to drive it so why this car is broke down so quickly. That is not acceptable to us.
NHTSA complaint #11531495 — an unverified report by a vehicle owner.
I was just driving normally boom engine light comes on take it to the dealership and it come up as crank case vent line which they quoted me 2300$. I think this should be recalled I have seen so many people with the same issue I have actually had someone tell me this was the only major problems with the w205 c300 before this happened. I think it should be recalled because from what I’ve seen it happens to every single c300 just at different mileages. Hopefully this will get a recall because it seems to be a very common issue and should be covered by the dealer.
NHTSA complaint #11527138 — an unverified report by a vehicle owner.
Mercedes Benz via American Service Center in Arlington, VA regarding the service they performed on my 2015 C300 W4 4Door Sedan AWD the following issues have presented: ISSUE: 03MBZZWARN1 ENGINE LIGHT TECH: 901844 PROBLEM: ENGINE HARNESS, ENGINE CONTROL MODULE, CRANKCASE VENT VALVE, AND O2 SENSOR BANK 1 CAUSE: FOUND OIL IN THE ENGINE HARNESS AND ENGINE HARNESS. OIL IS ENTERING THREW [SIC] THE CRANK CASE VENT VALVE. RECOMMEND REPLACING. Approximate miles at the time of this issue: 63,141. Cost of Repair: $8309.58 Yes, the vehicle is available for inspection. Safety concerns: The vehicle is not able to pass an emissions test with the engine light engaged. Per America Service Center in Arlington, VA, which is the only service center that has serviced the vehicle during my ownership, they commented and documented that oil is entering through a vent valve. My additional concerns are: If an odorless fume is passing into the passenger cabin and the vehicle can not pass state emissions these are immediate concerns. The service center advices that I may continue to drive the vehicle. However, I am concerned should the oil fully empty without warning the vehicle may fail while in use on a dangerous roadway due to cause and effect of additional unknown maintenance related operational co-dependent mechanical components.
NHTSA complaint #11524033 — an unverified report by a vehicle owner.