Engine light P052E, This seems to be a common problem with the C300.My concern is that Mercedes Benz hasn-€™t address the common issue. I own the car less than a year got it from Mercedes dealership and to be honest I expect Mercedes Benz to be better than the this to it customers

- Dallas, TX, USA

Failed positive crankcase ventilator after 40,000 miles common problem regulating oil consumption to the engine. Causing oil burn, oil leak, inconsistent oil ventilation. Dealer is aware of the problem. Engine light is on with code P052E. Commonly reported problem for this model on the internet.

- Smithtown, NY, USA

at 67000 miles the check engine light came on and is was engine code p052e crankcase ventilation regulator valve failure. This failure will cause the ending to exhaust increased contaniments in to the air. This is a know problem by MBUSA and they have changed the part design on new vehicles, this problems comes up right after the cars warranty and they cost to repair is in excess of $2500. For this to be an emission know problem by MBUSA a recall should be issued and this problem corrected under the recall process of the NHTSA ASAP. This has been reported to MBUSA and they have been zero help in this matter. The NHTSA is here to protect our citizens and environment and hopefully you will continue to do so.

- Andover, KS, USA

Code P052E just like all 2.0 turbo Mercedes Benz engines will get. This is a engineering defect and the cars with these engines should be recalled. I have researched and read that even after repaired this expensive engine defect will re-occur about every 35000 miles.

- Kings Park, NY, USA

initial observation started happening intermittently a week before the car become inoperable. When the vehicle came to a stop like at a light the engine would sound like it was going to almost turn off like a rattle noise and a popping sound or like I hit a plastic bag sound on acceleration. Then the day it broke down I was merging onto interstate 15 I heard the same popping sound, the engine light came on and my car broke down. My car was towed to Mercedes Benz of Ontario and inspected by technicians there and by the claims inspector for safe guard international (service protection plan i purchased with the vehicle)I was told it needed an entire new engine due to cracks in two pistons, etc. This was confirmed by the claims inspector with safe guard. This car was well maintained and only had 69,000 miles on it. I don-€™t think I need to explain the how my safety or the safety of others was at risk when my car breaks down in the middle lane on interstate 15 in California and I have to get over to the shoulder. This vehicle is available for inspection if needed.

- Victorville , CA, USA

Engine light appears due to P052e code -€œpositive crankcase ventilation regulatory valve-€. Part failed prematurely and appears to be a common problem in make/model. May cause engine damage due to inability to clear combustion gases in the crankcase.

- Durham, NC, USA

CRACKED PISTON AT 68K MILES The vehicle is very well maintained, only 68k miles, has had every oil change, only takes premium gas. I was driving it when the check engine light went on and the vehicle began shaking violently. After towing the vehicle to the Mercedes Benz dealership, they informed me that the piston cracked and they could not articulate a reason why this would happen.

- Ladera Ranch, CA, USA

My car engine shutoff at stop lights. it happened 3 times, the other 2 incidents happened at parking lots.

- Chino Hills, CA, USA

My Mercedes C300 2018 only have 33k miles on it, but I was leaking oil and gas from the positive crankcase ventilation valve which is not environment friendly. As I know many other who own Mercedes also have the same problem.

- Midlothian, VA, USA

CYLINDER 1 SPARK PLUGS IS DAMAGED DUE TO PISTON DAMAGE, HOLE IN PISTON. IF EXTRA DAMAGE IS FOUND ON TEAR DOWN, COMPLETE ENGINE REPLACEMENT. This is direct from the repair facilities reports. While driving my 2018 C-300 there was smoking out of tail pipe, a rough vibration, hard to control the vehicle and it was starting to lose power. Not a good situation, had to pull over and have vehicle towed to the dealership. Worst part is this is a vehicle used to transport my 5 children to and from school and activities. My 16 year old also drives this vehicle, had he been driving this with this happening to him, the outcome could have been catastrophic. Vehicle has been inspected by 2 facilities; first was a certified Mercedes Benz repair facility and the second was the service dept. of the Mercedes Benz dealership I have serviced at for over 10 years. Mercedes refuses to cover repair costs or even acknowledge the major vehicle malfunction and safety issue this presents., which is in my view ridiculous as cracked piston is not something that normally happens as the result of normal wear and tear, especially in a 3 year old luxury car. I have read several blogs on this same issue, Mercedesworld.org with over 400K members, reddit.com, benzworld.org, metrisforum.org, and numerous others. Please review these there are numerous people dealing with this and Mercedes is refusing to acknowledge. In addition, our Mercedes Benz service rep said these pistons were changed out in the 2019 model and newer due to these issues, he said he continues to see this issue with these models and advised Mercedes is well aware.

- Scottsdale, AZ, USA

When at a stop the engine will not restart sometimes. I have to start the engine manually. This has happened to me four times in 5 months.

- Aliso Viejo, CA, USA

The contact owns a 2018 Mercedes-Benz C300. While operating the vehicle, the contact noticed a burnt crayon odor inside the vehicle. The odor made it difficult to breathe inside the vehicle. The vehicle was taken to Mercedes-Benz of goldens bridge (321 NY-22, goldens bridge, NY 10526), but the cause of the failure was not determined. The manufacturer was notified of the failure. The failure mileage was 14,000.

- Somers, NY, USA