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 -€œnew motor-€ the -€œnew-€ 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

Check engine light appeared this morning, had the code scanned and found it to be P052E. This code is in reference to the Positive Crankcase Ventilation valve, which is responsible for routing excessive crankcase gases. After extensive research online, it would seem this is a known issue for Mercedes once they reach 50,000 miles, right outside of warranty. This is a very costly fix due to it being labor intensive. This should be a recall as it is a known mechanical issue, and even the dealers echo the same.

- Carmel, IN, USA

I made 2 engine stalling complaints at the dealership in 2021/2022.. the dealership kept my vehicle for 2 days and said nothing was wrong. My vehicle recently in stalled in drive gear, I had to cut the car off & turn it back

- Houston, TX, USA

PO52E code showed was the code pulled on my 2016 Mercedes c 300 4 matic. My car had 73000 miles on when I bought it and that code was pulled when I bought it. At 73000 miles my car shouldn-€™t have this problem.

- Holland , OH, USA

A fuel smell can be detected at idle inside the vehicle and around the engine area. A recall for some VIN's of this model in this year was enacted but not this particular model. No visible fuel moisture can be detected. A repair facility stated it might be a faulty clamp on the return fuel line. The recall was for dirt on manufacturing between the fuel injectors/fuel rail. This is a safety / emissions problem that hopefully does not lead into a fire. No warning lights are present. This started about 2 months ago

- Golden, CO, USA

Gas smell inside the cabin. Check engine light on. Took to dealer, stated P052e code came up. Positive crankcase ventilation valve went bad. The dealer says it is a pretty common problem for this vehicle and engine. Quote came back close to $2900 for parts and labor

- Houston, TX, USA

My check engine light came on at about 68,800 miles. The OBD code shows that I need the Positive Crankcase Ventilation valve replaced. The repair for this is approximately $2,300 and requires about six hours of shop labor, and the part costing over $425. I-€™ve never known a PCV replacement on any vehicle to be more than $60, with the part itself being about $10-$20. Most times, the part can be simply cleaned and replaced. This is very disappointing. Especially given that the engine design, just two years prior, would have been less than $200 for the same repair, with part costing about $60. The vehicle does not show any symptoms of the part being blocked, as indicated in the code. There is no hesitation, loss a power or decline in fuel efficiency. However, the engine light cannot be turned off until the part is replaced. I think that $2300 to replace a part on seven year old car, well under 100,000 miles is indicative of either poor design or predatory. Hopefully, something can been done to address this. Thank you!

- New Alexandria , PA, USA

Crankcase Ventilation Valve malfunction at under 50k. Check engine light is on and I took it into the shop after gas fumes were coming into the car through the ventilation system. I was informed that has been an ongoing issue with Mercedes and I was referred to fill out this document to try and kickstart a recall process. This is a problem that is very costly, and seemingly is happening to most recent models at around the 50k mark. Beyond that is is also a safety hazard as it is causing gas fumes to enter the cabin of the vehicle.

- Chicago, IL, USA

code P052E on 71000 miles. The crankcase vent valve replacement.

- Raleigh, NC, USA

My vehicle (2016 C-class 300) has a strong gas smell when the vehicle is cold and idling. Seems like it's common problem in W205 C300 cars. Taking to the dealership for diagnostics there is a class action investigation: Https://www.sauderschelkopf.com/investigations/automoti ve/Mercedes-C300-and-gla250- fuel -smell-class-actioninvestigation/ you can see multiple people complaining about the same fuel lines;

- Cincinnati, OH, USA

The contact owns a 2016 Mercedes-Benz C300. The contact stated he noticed an abnormal fume odor entering through the air vents of the vehicle. The contact self-diagnosed the vehicle as having a fuel leak from the fuel pump. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 83,000.

- Washington, DC, USA

CEL on, P052e code for crankcase ventilation/PCV failure. Vehicle has about 55k miles. Extremely common failure on these vehicles at this mileage and expensive/complicated to repair. Will not pass state emissions because of this. Given extensive anecdotal evidence of the pervasiveness of this problem, recall should be issue.

- Gaithersburg, MD, USA

2016 MB C300 41000 miles. Check engine light went on. Autozone code reader said p052e positive crankcase ventilationregulation value performance.

- East Islip, NY, USA

Cylinder 1 misfire initially, after taking it to an independent shop it was a piston 1 failure and required the small block to be replaced at 80,000 miles with a cost of $7000.

- San Diego, CA, USA

The crank case ventilation valve is bad. This part should be easily changed but the dealer wants over $3000. Happened at 62,000 miles.

- Moyock , NC, USA

(P052e) positive crankcase ventilation regularly valve

- Richmond , TX, USA

Check engine light code P052E

- Manassas , VA, USA

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

Crank case to be replaced.

- Overland Park, KS, USA

At approximately 65K miles, my PCV valve is bad and needs to be replaced at a cost of $1600. I saw lots of customer complaints for the same issue online, I think Mercedes should cover this item under recall.

- Lees Summit, MO, USA