2017 MERCEDES BENZ C300 Fuel/propulsion System Problems

29 complaints about Fuel/propulsion System

29
Complaints
0
Crashes
0
Fires
0
Deaths

This Problem Across All Years

All Fuel/propulsion System Complaints (29)

Dec 31, 2025

UNKNOWN it was just one day I started my car and turned the A/C on and I started getting this strong gasoline smell. I went on like a saw there is a recall for this problem for the M274 engines.

Nov 8, 2025

Cabin smells heavily like fuel and has a check engine light possibly a fuel leak

Nov 10, 2024

small to much gas inside the cab and outside and bouth seatbelt doosent work corectly

Oct 21, 2024

my whole entire car smells like gas. I cannot drive this car around because I will pass out and it is a safety hazard. There is a recall for this exact same issue, just not for my Vin number. I would like to get this done for my car, please.

Aug 20, 2024

Keep getting a code P052E! Changed the oil and code went away for a few days then came back. Looked into getting it fixed and it seems like Mercedes has known about this issue and hasn’t called for a recall on this piece of equipment! Very costly to fix and says it needs to be replaced every 30k to 50k miles! At around 1k to 3k to fix everytime that’s something they should recall

Jan 21, 2024

During cold starts the fuel injectors/clamps leak causing strong gasoline smell inside the cabin. After research online this is a common issue with W205 systems. I am beyond surprised this has not been investigated and reported as a safety recall as it can pose a fire hazard. Please investigate and Mercedes should be fixing this issue….

Jan 2, 2024

every winter this car will have a heavy smell of gas in the engine and the cabin, after driving it for around 15 minutes with the windows open in the cold it goes away. no problem in the summer time. My mechanic said it's a common problem with these cars.

Dec 19, 2023

There is a short rubber fuel line/hose in the engine compartment that is attached with compression clamps; the hose connects the fuel line from the gas tank to the high pressure fuel pump. When it gets cold outside (below ~40 degrees Fahrenheit) the clamps loosen a bit and the hose will leak gas The entire interior smells like gasoline, really bad.

Dec 11, 2023

code p052e came on randomly.

Oct 31, 2023

I have a 2017 C 300 and it smells like gas when I turn my heat/ac on. I contacted Mercedes to see if there was a recall as this is a huge issue with many customers but Mercedes offered no assistance. The smell of gas is very dangerous and I think it's unfair to the customers that Mercedes has known about this problem but chose to do nothing.

Sep 25, 2023

My engine light comes on intermittently for days or weeks at a time. Code is P052E indicating an issue with the PCV valve. I'm waiting to replace the part.

Aug 1, 2023

My Mercedes Benz stopped working. The mechanic shared it involves the: fault valve for crankcase ventilation has malfunction.

Jul 14, 2023

I got a check engine lite and the code said positive crankcase ventilation regulator valve. While doing research I am finding out that this is a very common problem on these cars, and very expensive to fix, I’ve never even heard of this problem happening to other cars. I think a recall is in order, thank you

Jul 8, 2023

Code PO52E

Apr 14, 2023

The valve for crankcase ventilation code P052E71 is not under emission warranty WHY ? 45K car and is not working and it will not pass emission test

Mar 2, 2023

I have a mercedes c300 2017 and recently I was driving my car and the check engine light came on all of a sudden so I took it to my local shop to diagnose it they told me it was the PCV valve, so I called mercedes and they’re telling me that this is not covered and of course my warranty is no longer covered I have about 63k miles on the car. Mercedes is saying they don’t have a recall for this but I’ve googled around and multiple people are saying the same issue happened to them around the 55-65k range. It’s super frustrating that this doesn’t flag a recall.

Feb 13, 2023

My preowned vehicle has a strong gas odor in the cabin while operating. I don’t see any safety recalls but I did read online that a class action lawsuit proved my model may have faulty fuel parts causing seepage and the watranty is extended to 10yr/120k miles. I have scheduled maintenance this week but would like to be certain the warranty will cover this. Thank you.

Jan 10, 2023

I purchased my 2017 C300 class Mercedes-Benz ("MB") in May 2021 from a used car dealership in Mobile, AL. At that time it had 36,000 miles. Less than 2 years later, on or about 12/15/22, as I was driving, the MB suddenly and without warning began to vibrate violently and immediately lost power. The car had @54,000 miles on it. I routinely drive interstate to and from work and had just gotten off of the interstate. I was lucky that I was driving at a low speed when this happened; otherwise, a serious accident could have resulted. I took it to the local MB dealership which told me that the car failed a compression test in the #1 cylinder and that the engine would have to be replaced. Subsequent research on the cause of this total engine failure with low mileage revealed that this engine has a chronic piston defect that damages the #1 cylinder, causing it to lose compression, and that MB has known about the defect for many years, an issued an internal bulletin about it. MB has not alerted the public nor instigated a recall. I was not informed by MB at any time that the C300 class engine had a chronic piston defect that would damage the #1 cylinder which would, in turn, cause the engine to lose power and the vehicle to vibrate and shake, creating a dangerous diving condition under all circumstances, but especially if the car was being driven at speed on a federal interstate highway. Despite demands by me and others, MB refuses to responsibly address the issue. The driving public is, and remains, clearly, in great risk of harm due to this defective engine and associated power train issues. It is patently unreasonable for MB to produce and market such a unsafe, dangerous and defective product that poses an unreasonable risk of harm to its customers and others when being used as it was intended. I understand that the NHTSA has opened an investigation on this defect and wish for my voice to be heard on it. Please contact me [XXX] for further details. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION A

Sep 17, 2022

Please see attached letter: [XXX] Mercedes Benz Crankcase Valve Claim.pdf, repair estimate and other correspondence from Mercedes-Benz. This is an well-known issue where there is a gas lead from the engine where Mercedes insists doesn't pose a safety issue. During cold starts there is a smell of gas in the cabin and this is prevalent in colder climates like New England. Mercedes should make cars for all markets that are safe. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

Jun 28, 2022

Diagnosis code P052E PCV regulator valve replacement/crankcase replacement. Dealership does not want to acknowledge code while car was under warranty despite proof that it existed when check engine was diagnosed. Now code keeps coming back with check engine light on dashboard. To replace part, the engine has to be taken down since the crankcase is inside the engine. This is a malfunction during assembly/manufacturing, it is impossible to damage part while under usage. Mercedes Benz should be held responsible for part replacement and labor. I urge you to investigate this matter with other clients and ask the manufacturer to replace part and pay for labor.

Apr 18, 2022

At approximately 26,500 miles of use, the check engine light came on in my Mercedes Benz C300. I brought the vehicle to the dealership and they informed me that the diagnosis was a crankcase vent valve malfunction. The MB fault code is P52E71. After paying Mercedes to fix the issue, I found forums on the internet where many other MB owners reported the same issue at around the same mileage. Being that this seems to be a common malfunction with the C300, I believe that it should be considered as a recall issue. I don't know what could have happened if I didn't service the vehicle, but any engine issue is dangerous while a vehicle is in motion.

Feb 23, 2022

When starting the car in the morning there is fuel smell that gets into the cabin. Additionally, as the car is idle during the drive, the smell of fuel is very obvious. Windows have to be rolled down to avoid the smell

Nov 6, 2021

Strong gas smell when car is idling and miles to empty goes down very quickly, approximately a mile or more a minute. There is no recall for this problem and Mercedes is very aware of this problem.

Oct 25, 2021

Strong gas odor in the cabin and in motion to the point of causing me to be light headed with my children in the car. Smell of gas coming from the engine when parked. No lights or warnings and it does not occur all of the time just sometimes however ive noticed it 3x the last 5x i have drove my car, the cabin was only extremely bad once.

Aug 22, 2021

MB USA extended the warranty coverage on the low pressure fuel hoses that connects to the high pressure fuel pump. The reason is "under certain cold ambient conditions during a cold start of the engine, the low pressure fuel hose at that connection may experience slight fuel weeping". MB USA, however, ruled out a safety risk. NHTSA needs to investigate it. If MB USA found the fuel pressure line is defective, they needed to do a recall. I believe it must be a recall as fuel leaks is not only a safety risk but also a serious health hazard to the occupants. What if the occupants have sinusitis and don't smell well. What if the leaks is too small to smell enough but can still be a health issue.

Feb 13, 2021

A FUEL LINE IN THE ENGINE COMPARTMENT JUST ABOVE THE SKID PLATE ON THE DRIVES SIDE JUST RIGHT OF THE FRONT WHEEL WELL LEAKS FUEL WHERE THE LINE IS CRIMPED COMING FROM THE HIGH PRESSURE FUEL PUMP. FUEL COLLECTS ON THE SKID PLATE AND WHEN A STOP AT IDEA PRODUCES A STRONG FUEL SMELL IN THE CABIN OF THE CAR

Mileage: 47,000

Feb 10, 2021

GAS LEAKING IS COMMON ISSUE AND WHEN TURNING CAR ON THERE IS A GAS SMELL. WHEN TURNING HEAT ON THERE IS A GAS SMELL. MERCEDES BENZ SAID THERE IS A LOT OF ISSUES WITH THE CLAMPS. IT IS A COMMON ISSUE. CAN CAUSE FIRE.

Jan 11, 2020

EXHAUST WAS COMING INTO THE CAR FOR MONTH. WHEN I STARTED THE CAR TO LET IT WARM UP IN WINTER MONTHS, I WOULD GET IN AND WONDER WHY I SMELLED GAS OR FUMES. FIGURED IT WAS FROM SITTING. NO DASHBOARD LIGHTS CAME ON, NO C02 SENSORS IF THERE ARE ANY, NOTHING CAME ON IN THE INTERIOR TO WARN ME THERE WAS AN INSANE. ONE PERSON TOLD ME THE PART WAS 'DEFECTIVE' ANOTHER PERSON TOLD MY BOYFRIEND THE PART WAS 'SPLIT MOST LIKELY FROM ROAD CONDITIONS' - THIS PUT MY LIFE AND MY 10 YEAR OLD'S LIFE AT RISK. IT REALLY NEEDS TO BE CHECKED OUT BECAUSE THE C300 COUPE IS RIDDLED WITH SMALL IDDUES

Mileage: 15,555

Nov 12, 2019

TL* THE CONTACT OWNS A 2017 MERCEDES-BENZ C300. WHEN THE CONTACT STARTED THE VEHICLE WITH THE MOBILE APP, SHE NOTICED A FUEL ODOR EMITTING FROM THE VEHICLE. WHEN THE VEHICLE WAS STARTED MANUALLY, THE ODOR WAS NOT PRESENT. THE CONTACT TOOK THE VEHICLE TO PARK PLACE MOTORCARS DALLAS (LOCATED AT 6113 LEMMON AVE, DALLAS, TX 75209, 877-475-5033) WHERE IT WAS DIAGNOSED THAT THE FUEL HOSE WAS LEAKING AND NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 55,000.

Mileage: 55,000