9.8

really awful
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
346 miles

About These NHTSA Complaints:

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problem #13

Apr 082024

C300

  • miles
I need Positive Crankcase ventilation valve replace It's a common repair that comes up with these makes/models

- Visalia, CA, USA

problem #12

Mar 232024

C300

  • miles
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.

- Frankly Park , IL, USA

problem #11

Jan 212024

C300

  • miles
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

- Carmel, IN, USA

problem #10

Oct 192022

C300

  • miles
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

- Brooklyn , NY, USA

problem #9

Apr 172023

C300

  • miles
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.

- Queens, NY, USA

problem #8

Jun 142023

C300

  • miles
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.

- Roanoke, IN, USA

problem #7

Oct 192022

C300

  • miles
I bought the car with 51k miles. Engine failed at 71k miles, due to piston #1 cracking. Almost caused me to get rear ended on a busy street. I went to the dealership and they charged me $10250 to replace the engine with a remanned long block and they offered a 2 year warranty. 9 months, only 19k miles on -??new motor-?? the -??new-?? engine fails again -?? same reason piston # 1 cracked failed suddenly on the highway and I had to push the car to safety to the emergency lane while cars where coming.. I went back to dealer demanding a replacement and told them this is a common occurrence and they refused to help me. I called corporate. They refused to help me saying I would have to purchase an engine for the second time out of pocket when it only lasted 9 months. This is a big fault in the m274 engine -?? it-??s also a safety hazard that can cause serious injury, fire, or even a deadly accident. I read that it-??s a common issue with these engines.

- Sioux Falls, SD, USA

problem #6

Dec 172022

C300

  • miles
I have owned the vehicle for only about 4 months. My wife took the car out for a short errand and returned to tell me that the engine light was on. I took the vehicle to AutoZone and had the code ran on their diagnostic computer and it returned a P052E code for -??Positve Crankcase Ventilation Regulation Valve Performance-??. I have done a lot of research and have learned that this is a common problem and incurs huge financial impact to unsuspecting buyers. Mercedes has even made improvements to the part because of this issue. It-??s not safe due to the possibility of oxygen build occurring in the combustion chamber. This part should be recalled and repaired by Mercedes.

- Marietta, OK, USA

problem #5

Oct 082022

C300

  • miles
my engine failed at 82k odometer miles. replaced it with a new engine for $10065. and they said it was fixed and working normal, 2nd engine failed at 111000 miles. and has warranty. they refuse to fix it for a 3rd time...... this is a common problem with m274 engines. please help us m274 engine owners.... its a very widespread known problem...

- Sioux Falls, SD, USA

problem #4

Jun 082022

C300

  • miles
While driving the check engine light came on. The inside of the car started to smell like gas. A diagnostic check was performed at the Mercedes dealership and it was determined that there were 2 faults: low boost signal & ME control unit this was due to oil leaking from the crankcase vent line through the engine wiring harness and into the ME (engine module).

- Maumelle, AR, USA

problem #3

Jul 012021

C300 4-cyl

  • miles
Transmission shifted into neutral after coming to a stop. Brake was applied. Similar issue to NHTSA Campaign 21V033000 for 2019 GLA 250.

- Palm Coast, FL, USA

problem #2

Mar 022017

C300

  • 3,592 miles
When at a red light and the car is idling, all of a sudden the car jerks forward. If the brake is not engaged hard, I have experienced the car feeling like it will lunge forward. This occurs each and every time I am idling at a red light.

- Miami, FL, USA

problem #1

Aug 222016

C300

  • 900 miles
C300 anti collision sensor malfunction light displayed and loss engine power for several seconds. The car was traveling aprox 20 mph at the time on city street. Then power resumed, the warning light went out. Mercedes-Benz of temecula, ca could not find a problem. Workorder 229423, 9/13/16

- Temecula, CA, USA