2017 Mercedes C-Class

The contact owns a 2017 Mercedes-Benz C300. While driving at approximately 15 mph, the contact observed smoke emanating from under the hood. The vehicle was driven to her work location and parked. Upon exiting the vehicle and opening the hood, she observed orange flames coming from the engine compartment. A parking attendant extinguished the fire, and a police and/or fire report was filed. The vehicle was towed to a dealer and diagnosed with a fuel line leak that caused the engine harness to come apart. The leaking fuel hose from the high-pressure fuel pump caused damage to the high-pressure pump, engine harness, vacuum transducer, and coolant feed line from the thermostat to the firewall. The following components needed replacement: high-pressure fuel pump, rubber fuel hose, engine harness, pressure transducer, and intake manifold. The vehicle was repaired. Five months later, the contact experienced another failure she believes was associated with the engine fire. While parked and attempting to start the vehicle, it did not start. The vehicle was towed to a dealer and diagnosed with a faulty starter that needed replacement. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 65,422.

Reported

May 2026

Incident date

Oct 2025

Mileage

Not provided

Outcome flags

Fire

strong evident fuel/ gas smell when driving and when the car is in park after driving.

Reported

May 2026

Incident date

May 2024

Mileage

Not provided

Outcome flags

None reported

Check engine light for P052E which has been coming and going off for years now. Now the check engine light is there permanently. I spoke to Mercedes Benz customer service and requested for them to fix the problem now that the light is on permanently but they refuse to fix it because the car has 222,000 miles on it. This should be a recall from the manufacturer not an extended warranty coverage. The Mercedes dealer in Valencia California told me they now only do a software update and put a plug cap on the sensor and want to charge me $850 even though this should be a recall

Reported

Mar 2026

Incident date

Mar 2026

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz SLC300. The contact stated that while driving at an undisclosed speed, there was a loud whistling sound coming from the upper panel of the roof. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that the bonding of the upper roof panel had failed and required to be replaced. The vehicle was not repaired, and the contact was referred to the dealer for additional assistance. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline for further assistance. The failure mileage was not available.

Reported

Jan 2026

Incident date

Jan 2026

Mileage

Not provided

Outcome flags

None reported

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.

Reported

Dec 2025

Incident date

Dec 2025

Mileage

Not provided

Outcome flags

None reported

While driving home from work, without any warning or blunt force the sunroof exploded and shattered glass was everywhere

Reported

Dec 2025

Incident date

Dec 2025

Mileage

Not provided

Outcome flags

None reported

any action on Case 11699173 ?

Reported

Dec 2025

Incident date

Nov 2025

Mileage

Not provided

Outcome flags

None reported

Case already called in 11699173 - Stuck Seatbelt in B Pillar of 2017 Mercedes Benz 2 door hard top coupe. Seat belt will not come out of A pillar rendering seatbelt totally inoperable This VIN comes up negative under recall 21V03200 Case filed with MBUSA 18991593 still unresolved. Dealership is claiming a 2,200 Seatbelt Assembly is needed. now warning lights. The seatbelt was " lazy " and didn't smoothly retract prior to this incident when parked, door closed, the belt retracted with a loud motorized noise and now will not retract at all from A Pillar - Please follow up with on this Case # already called in over a week ago

Reported

Nov 2025

Incident date

Nov 2025

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz C300. The contact stated that upon arriving at his destination and exiting the vehicle, the driver’s side seat belt retracted and became stuck in the retracted position. As a result, the contact was unable to use the driver's side seat belt. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the seat belt assembly. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 21V032000 (Seat Belts), but the VIN was not included. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 67,000.

Reported

Nov 2025

Incident date

Nov 2025

Mileage

Not provided

Outcome flags

None reported

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

Reported

Nov 2025

Incident date

Sep 2025

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving 65 MPH on the highway, the contact heard a popping sound coming from an unknown part of the vehicle. The contact pulled over to the side of the road, exited the vehicle, and became aware that the roof panel had shuddered. The contact stated there was no glass in the vehicle. No injuries were sustained. The contact stated that the failure had occurred on two occasions. The vehicle was not taken to an independent mechanic or the dealer to be diagnosed. The vehicle was taken to the dealer by the previous owner to be repaired under NHTSA Campaign Number: 21V197000 (STRUCTURE); however, the recall repair failed to prevent the failure. The manufacturer was notified of the failure and informed the contact that there was no recall related to the failure. The manufacturer offered the contact a trade for the vehicle. The failure mileage was 105,000.

Reported

Nov 2025

Incident date

Jul 2022

Mileage

Not provided

Outcome flags

None reported

I am reporting a serious vehicle safety hazard caused by improper and unsafe repair work performed by USA Platinum Motor, located at 1221 California Lane #126B, Arlington, TX. I brought my 2017 Mercedes-Benz C300 in for a cold start rattle with no warning lights or prior issues. The shop diagnosed a loose timing chain and I authorized the repair. After the repairs, the vehicle was returned with critical safety defects, including a loose fuel pump, unsecured fuel line, missing bolts, and improperly reassembled engine components. Shortly after pickup, the car experienced loss of acceleration on the interstate, a strong odor of fuel, and a sudden loss of power, creating a dangerous and life-threatening situation. The vehicle had to be towed back to the shop. The manager, who is not a certified mechanic, admitted he personally “fixed” the issue by tightening the fuel pump himself. A Mercedes-Benz diagnostic inspection later confirmed multiple severe assembly errors, including missing fasteners, unsecured oil cooler, disconnected vent lines, and other safety-related defects in the fuel and cooling systems. These unsafe and negligent repairs created an extreme fire hazard, engine instability, and risk of sudden failure while driving. I am requesting a formal NHTSA investigation into this matter to ensure vehicle safety compliance and to prevent similar incidents affecting other consumers.

Reported

Oct 2025

Incident date

Oct 2025

Mileage

Not provided

Outcome flags

None reported

This is the same as recall for NHTSA ID: 21V-197. The panel flew off my 2017 Mercedes C300 W205. My vin number is not included in the recall. This is a safety issue and will need to be replaced.

Reported

Oct 2025

Incident date

Oct 2025

Mileage

Not provided

Outcome flags

None reported

See attached document for complaint.

Reported

Oct 2025

Incident date

Sep 2025

Mileage

Not provided

Outcome flags

None reported

Sunroof detachment Sunroof fell off while driving

Reported

Oct 2025

Incident date

Oct 2025

Mileage

Not provided

Outcome flags

None reported

On September 6, 2025 while driving approximately 70 mph, the front roof panel of my vehicle detached completely. This was not only a costly failure, but also an extremely dangerous incident that could easily have caused severe injuries or fatalities — either to myself, my passengers, or other motorists on the roadway. As you are aware, Mercedes-Benz has already acknowledged this precise risk through NHTSA Recall No. 21V197000 / Campaign 2021070010, later expanded under NHTSA Recall 23V854000. These documents confirm that the bonding adhesive used on the front roof panel can deteriorate, leading to detachment. Mercedes has therefore had prior knowledge of this defect and its associated safety hazards. Given that my vehicle has now experienced the exact failure described in these recalls, it is wholly unreasonable for Mercedes-Benz to deny responsibility. This was not normal wear and tear; it was a known, documented safety defect that could have resulted in catastrophic consequences.

Reported

Oct 2025

Incident date

Sep 2025

Mileage

Not provided

Outcome flags

None reported

Sunroof Front Trim for Mercedes-Benz GLC300 IS ALL SCRATCHED BUT MERCEDES BENZ SAYS IT IS NOT COVERED BY THEM.

Reported

Sep 2025

Incident date

Apr 2022

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving at 60 MPH, the contact became aware that an unknown part had detached from the vehicle. The contact stated that after stopping to refuel the vehicle, it was discovered that the roof panel was missing. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The contact related the failure to NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 129,000.

Reported

Aug 2025

Incident date

Aug 2025

Mileage

Not provided

Outcome flags

None reported

The sunroof exploded spontaneously while driving to a destination. When the incident happened, I was stopped at a red light. I panicked as it sounded like gunshots hitting my car. I pulled over to the nearest safest destination to inspect the car. This put the safety of myself at risk and others at risk who were driving along the sides and/or behind me. This incident was confirmed by a dealer, as I went to Mercedes Benz Sugar Land on the following day of the incident and was quoted around $3,700 to have it repaired. The vehicle not been inspected by police and/or insurance. There were no warning signs that this could have happened besides the fact that Mercedes Benz USA is currently under an active lawsuit for this happening to several other drivers. I do believe that this is a manufacturing defect affecting safety, as similar incidents involving Mercedes-Benz panoramic sunroofs, which may indicate a wider defect trend.

Reported

Aug 2025

Incident date

Aug 2025

Mileage

Not provided

Outcome flags

None reported

In October 2024, the rear subframe was replaced due to rust perforation in the area of the suspension arm mounting bracket. I had no warning. The car was in for routine service at Mercedes Benz of New London. It had rusted from the inside out and was considered unsafe to drive by the Mercedes service advisor. I could have had a serious accident! I had no choice but to replace the subframe as it is my only vehicle. Shockingly I learned many others have had this issue with various Mercedes models/years and that Mercedes Benz knows of this serious safety problem and there is a class action lawsuit pending but subframe replacement is not covered under warranty by Mercedes Benz, so the cost was mine to bear.

Reported

Jul 2025

Incident date

Oct 2024

Mileage

Not provided

Outcome flags

None reported

My car caught on fire due to AC malfunction

Reported

Jul 2025

Incident date

Apr 2023

Mileage

Not provided

Outcome flags

Fire

The contact owns a 2017 Mercedes-Benz C300. The contact stated that both the front driver’s side seat belt and front passenger's side seat belt had failed to retract as needed. There was no warning light illuminated. Additionally, the contact stated that the seat belts buckles would unintendedly lodge under the seats. The vehicle was taken to the local dealer, but was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 21V032000(Seat Belts); however, the VIN was not included. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was unknown.

Reported

Jun 2025

Incident date

Jan 2017

Mileage

Not provided

Outcome flags

None reported

The sunroof is very glitchy and this is common in all Benz I have had a few different Benz and they all eventually have this same issue with their panoramic sunroof. Sometimes it opens half way life one side is up and the other side is closed and other times it will open fully but not close and other times it won’t open at all. This is a common problem that many Benz owners have stated this in the Benz forums all over. This is a safety issue due to unexpected weather conditions if it rains and it’s stuck inside gets damage and owners get wet which is also a distraction and may cause accidents. Please investigate this issue thoroughly. Their sunroofs should be recalled and extended warranties placed on them automatically by Mercedes Benz due to this being a very common issue in all model’s panorama sunroofs particularly C300s year 2017 thank you for looking into this matter.

Reported

Jun 2025

Incident date

Mar 2025

Mileage

Not provided

Outcome flags

Crash

unknown

Reported

Apr 2025

Incident date

Apr 2025

Mileage

Not provided

Outcome flags

None reported

ESP control unit software Recall 2016090002 Recall 2017110002 Recall 2020080016 And my car shows there’s cero recall active but is giving me problem showing code: U0121 u1110 U0122 B227d U0423 B227d

Reported

Apr 2025

Incident date

Mar 2025

Mileage

Not provided

Outcome flags

None reported

this is my send time writing in. mercedes used the wrong wrist pins for the pistons leading to my wife getting a cracked piston on freeway in phx.if you look up cylinder 1 issues on this model there is a lot of people who have encountered this. why this hasn't been recalled and sticking consumers with a10k plus repair is beyond me. if you use the wrong parts you should be responsible for the repair!!!

Reported

Feb 2025

Incident date

May 2024

Mileage

Not provided

Outcome flags

None reported

Error code P052E71 on a 2017 c300 with 100k miles. It seems to be a very common and recurring issue that appears to have no real solution and is costing consumers thousands upon thousands. This malfunction does relate to emissions and this vehicle is operated in California.

Reported

Jan 2025

Incident date

Jan 2025

Mileage

Not provided

Outcome flags

None reported

PVC VALVE CODE. P052E Mercedes should fix this!

Reported

Jan 2025

Incident date

Jan 2025

Mileage

Not provided

Outcome flags

None reported

The valve for crankcase ventilation has a malfunction. The actuator is blocked Select 'Error codes / Events' menu in Engine Control Unit. Then read fault memory.

Reported

Nov 2024

Incident date

Nov 2024

Mileage

Not provided

Outcome flags

None reported

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

Reported

Nov 2024

Incident date

Nov 2024

Mileage

Not provided

Outcome flags

None reported

I have an error code: P052E.

Reported

Oct 2024

Incident date

Oct 2024

Mileage

Not provided

Outcome flags

None reported

When i scan my vehicle there are Mercedes Benz fault codes pertaining to the electrical system but also recalls that haven’t been done but when looking Mercedes Benz web site and NHTSA WEBSITE these are aren’t showing up as my particular chassis being included as part of the campaign

Reported

Oct 2024

Incident date

Oct 2024

Mileage

Not provided

Outcome flags

None reported

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.

Reported

Oct 2024

Incident date

Oct 2024

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz C300. The contact stated while driving 65 MPH, there was a loud banging sound coming from the roof of the vehicle, prior to the glass sunroof panel being ejected from the roof panel and landed on the roadway. The cause of the failure was not yet determined. The local dealer and manufacturer were notified of the failure. The failure mileage was 84,000.

Reported

Sep 2024

Incident date

Sep 2024

Mileage

Not provided

Outcome flags

None reported

I purchased my 2017 Mercedes c class coupe in 2020, used. Around 2021, I started hear noise from the sunroof when driving on the highway. I went to get it repaired and they mentioned they needed to tighten the screws. This week, I was closing my sunroof and then I heard a crack. I went to a shop to get it manually closed for now on calis 105 degree heat. I am now learning there has been recalls for Mercedes 2017+ coupes but it’s not stated for my specific car to get it fixed. How do I go about this? I feel the sunroof is faulty and has been faulty.

Reported

Sep 2024

Incident date

Sep 2024

Mileage

Not provided

Outcome flags

None reported

The glass on the panoramic sunroof exploded/shattered under normal driving conditions. It was raining but not too heavy. It didn’t appear that anything hit the glass and no potholes were hit. It seemed to be due to pressure or temperature which caused the explosion which sounded like a loud gunshot and the glass was in pieces. There were no injuries as the sunroof shade was closed and thus the glass fell on the shade. It has not been inspected by dealership or insurance as closed on Sunday and today due to Labor Day, but yes it is available for inspection upon request. However, as it was raining and I needed to get home, I covered the entire sunroof with Duct Tape.

Reported

Sep 2024

Incident date

Sep 2024

Mileage

Not provided

Outcome flags

None reported

The same part that was recalled the Starter Current Limiter has overheated again. The dealership is trying to charge for this same part for diagnostic, parts and labor. The car produces smoke around the battery and melted due to overheating. The battery is new. The car only turns over..then immediately overheats. Just because it was recalled and replaced does NOT mean it is perfect from defaulting again. Please have someone look into this matter.

Reported

Aug 2024

Incident date

Aug 2024

Mileage

Not provided

Outcome flags

None reported

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

Reported

Aug 2024

Incident date

Aug 2024

Mileage

Not provided

Outcome flags

None reported

P052E code for PCV vent valve

Reported

Aug 2024

Incident date

Aug 2024

Mileage

Not provided

Outcome flags

None reported

cracked piston in cylinder #1. After doing research this is a common problem in the m274 engine from 2015-2018 which Mercedes is aware of but does nothing. mercedes need to be held responsible and a recall issued. This isn't a 2 or 3 thousand dollar repair!! this repair is 6 figures!!! Please hold them acountable!!! THX

Reported

Aug 2024

Incident date

May 2024

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz AMG C43. The contact stated that the front driver’s side seat belt failed to retract as intended. No warning light was illuminated. The vehicle was taken to a local dealer for diagnosis but was not repaired due to the cost. Upon further investigation, the contact related the failure to NHTSA Campaign Number: 21V032000 (Seat Belt); however, the VIN was not included. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 70,000.

Reported

Aug 2024

Incident date

Aug 2023

Mileage

Not provided

Outcome flags

None reported

Check engine light on. Test results: Positive Crankcase Ventilation Regulator Valve Performance CODE : P052E

Reported

Jul 2024

Incident date

Jul 2024

Mileage

Not provided

Outcome flags

None reported

Part 573 Safety Recall Report 21V-032 Manufacturer Name : Mercedes-Benz USA, LLC NHTSA Recall No. : Manufacturer Recall No. : JAN 29, 2021 21V-032 NR Manufacturer Information : Manufacturer Name : Address : Mercedes-Benz USA, LLC Company phone : 1-877-496-3691 13470 International Parkway Jacksonville FL 32218 Population : Number of potentially involved : Estimated percentage with defect : Vehicle Information : Vehicle 1 : 2017-2021 Mercedes-Benz C300 Vehicle Type : LIGHT VEHICLES Body Style : Descriptive Information : Power Train : GAS 2-DOOR Production Dates : Mercedes-Benz MY2017-2021 C300 18,589 vehicles. The recall population was determined through production JAN 19, 2016 - JUL 17, 2020 records. I was told this was not under recall when I found it is. The seat belt won’t retract. Please advise.

Reported

Jul 2024

Incident date

Jul 2024

Mileage

Not provided

Outcome flags

None reported

Car check engine light came on with only 62,000 miles. Diagnosed as code P052E, the issue is the positive crankcase ventilation valve being faulty. Regular oil changes and maintenance was done. I see multiple complaints with this issue, why is this not recalled? It is very expensive to have fixed.

Reported

Jul 2024

Incident date

Sep 2023

Mileage

Not provided

Outcome flags

None reported

My engine light keeps coming on and off on my 2017 C300 4matic coupe. I got the problem diagnosed in March 2023. Benz said I had a faulty solenoid valve and that I would need to replace the crank case ventilation assembly. That is $3000. My friend has a C300 sedan and they replaced his under the extended warranty that came out on August 2023 for the crankcase. I have the same exact issue but they said my VIN doesn’t populate so they cannot do anything. This is the 2nd faulty crank case in my car, it was replaced by warranty in 2019. I don’t drive that much I have 47K miles on the car. They refuse to cover the faulty part.

Reported

Jul 2024

Incident date

Mar 2023

Mileage

Not provided

Outcome flags

None reported

My gas door has fell off 3 times exposing my gas cap. I got it replaced twice. It fell off on the highway and the other times I was just doing gas and it fell off into my hand. No excessive force. I didn’t want to pay again to repair it so I just taped it.

Reported

Jul 2024

Incident date

Jul 2023

Mileage

Not provided

Outcome flags

None reported

I currently have a 2017 Mercedes C300. The panel between the windshield and main panel of the panoramic roof (above the driver) is deteriorating and doesn’t not seem to be fully attached anymore. I had the exact same model but a year older in the past and this same part deteriorated and was subject to recall. I believe there is not only an issue with the part itself, but how Mercedes has bonded these parts to the roof.

Reported

Jun 2024

Incident date

Jun 2024

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes-Benz C300. The contact stated that while operating the vehicle, the front driver’s and front passenger’s side seat belts malfunctioned and failed to properly retract. The cause of the failure was not yet determined. The local dealer and manufacturer were notified of the failure, but no assistance was provided. The contact was informed that the vehicle was previously serviced under NHTSA Campaign Number: 21V032000 (Seat Belts). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 48,956.

Reported

May 2024

Incident date

May 2024

Mileage

Not provided

Outcome flags

None reported

Piston 1 broken at 76000 miles. Compleat engine failer

Reported

May 2024

Incident date

May 2024

Mileage

Not provided

Outcome flags

None reported

The contact owns a 2017 Mercedes Benz C300. The contact stated that while making a left turn at 40 MPH, another vehicle crashed into the front passenger side of the vehicle. The air bags did not deploy upon impact and the seat belt also failed to restrain the contact during the crash. Due to both failures, the contact's head and chest hit the steering wheel. The contact was taken to the hospital by ambulance and given an X-ray exam. The contact was treated for lacerations to the forehead and suffered pain to the head, neck, back, and chest. The whereabouts of the other driver were unknown. A police report was filed. The vehicle was initially towed to an independent mechanic and later back to the contact's home where it remained in the contact's possession. Neither the dealer nor the manufacturer were notified of the failure. The vehicle was not repaired. The failure mileage was unknown.

Reported

May 2024

Incident date

May 2024

Mileage

Not provided

Outcome flags

Crash 1 injuries