NHTSA Owner Complaint Log
This page lists owner-reported complaints filed with NHTSA for the 2016 Mercedes-Benz C-Class. Complaints are unverified consumer reports submitted to NHTSA and do not by themselves prove a defect or defect rate.
The contact owns a 2016 Mercedes-Benz C300. The contact stated that the adhesive bonding on the front panel of the sunroof had failed, and the panel detached from the vehicle and the sunroof could no longer be opened. The cause of the failure was not yet determined, and the vehicle was not repaired. The manufacturer was contacted and informed the contact that the VIN was not included in NHTSA Campaign Number: 21V197000 (Structure). The contact stated that the vehicle had experienced the failure listed in the recall. The local dealer was not contacted. The failure mileage was 52,000.
Horrible fuel smell coming through Air conditioning vents on cold start up. This presents a safety hazard as there is an obvious fuel leak on a still late model vehicle with no safety recall in sight.
P052e positive crankcase ventilation
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.
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
Strong smell of gasoline on a daily basis for 3 months. Took vehicle to mechanic's and was informed that the fuel lines were leaking. Was shown the cracked lines.
Check engine light code P052E
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...
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.
I have a 2016 C300 that was diagnosed with a severe brake booster issue. Last week, I had to brake hard while traveling 65 mph on a highway and they failed; luckily I was able to avoid catastrophe by maneuvering around the obstacle. I researched to see if this was a known issue and learned that some Mercedes models between 2008-2012 had recalls due to brake booster corrosion issues, but Mercedes might have a worse issue than just a few models prior to 2012, based on my experience!
I bought my 2016 merecedes Benz c 300 4 matic with an engine light on . I took it the dealership and is the positive crankshaft failed . The crankshaft could reduce power on car . At 73000 mile the crankshaft should have not failed .
Crank case to be replaced.
Crankcase ventillation valve assembly needs replacement
the Burl wood trim panel on the interior doors are deteriorating , the drivers side panel is deteriorating to the point that it looks like acid is eating away at the material there is red markings showing .. i find this could be a safety hazard as it could eat away at the door itself. i have pictures of evidence. there was a recall on Mercedes E class during the same years i purchased my car, my car is the C-class which was not part of the recall, but falls into the same category as time frame of purchase. Mercedes told me to contact you. i look forward to your response as this is a safety concern thank you
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.
Front Stationary Sunroof Panel (between the windshield and the sunroof) deteriorating and cracking in the middle. I've read about a recall on previous year models that will extend to this year model or even further year but waiting on this recall to reach my vin number. I've seen same model year in other states have this issue resolved with the recall update in Feb 2024. This is related to the NHTSA Recall ID: 23V854.
The crank case ventilation valve is bad. This part should be easily changed but the dealer wants over $3000. Happened at 62,000 miles.
I took my 2016 Benz through a car wash and realized the glass in front of my sunroof that is part of windshield is loose . I can hear wind coming through when I drive . This is driving hazard .
The contact owns a 2016 Mercedes-Benz C300. The contact stated after starting the vehicle with the heater running, there was an abnormally strong gasoline odor coming from the vehicle. The vehicle was not diagnosed nor repaired. The manufacturer was not contacted or informed of the failure. The failure mileage was 90,000.
I bought my 2016 merecedes benz c300 4 matic with the engine light on .when I did a diagnostic on it came back to a po52e is bad . It had 73000 on it when I bought . Now I sit at 77000 miles with the bad part .
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 .
The check engine light came on. I pulled the code and it was P052E, and requires the replacement of the crankcase ventilation system. I am told that this happens on virtually all C300s and (and maybe the GLC300 also). I think this should be recalled.
The contact owns a 2016 Mercedes-Benz C300. The contact stated that upon purchasing the vehicle, the driver's side sunroof corner was slightly raised. The contact stated while driving at 40 MPH, she heard the panoramic sunroof glass sliding back and forth. The contact stated that she held the sunroof glass while driving. The contact stated that the failure had been reoccurring. Additionally, the contact stated while attempting to open the sunroof, it slightly opened and the force itself closed. The dealer was not notified of the failure. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline. The failure mileage was approximately 73,000.
Check engine light came in so I took it to a local auto shop. They ran the diagnostics and the code that appeared was P052E(Positive Crankcase Ventilation Regulation Valve Performance).
The contact owns a 2016 Mercedes-Benz C300. The contact stated while driving 45-60 MPH, the vehicle began to stall. The contact depressed the accelerator pedal several times but the vehicle failed to respond. The vehicle stalled. The contact was able to veer to the side of the road. The contact was able to restart the vehicle. The check engine warning light and several unknown warning lights were illuminated. The vehicle was towed to the contact’s residence. The vehicle was then towed to the local dealer where it was diagnosed that the fuel pump and fuel tank needed to be replaced. The vehicle was being repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 61,000.
CEL light- with code P052e positive crankcase ventilation regularly valve. Vehicle only has 62,000 miles
This is a plug-in hybrid car and twice in the last two weeks, the car while in motion on the road, has randomly turned off the engine and lost power. The gas pedal is unresponsive and all the alarms on screen flash and I have to coast to a stop. Most recently it was on a busy road and I barely missed being rear-ended. This is an unsafe situation and has happened twice and the only thing which I can do is come to complete stop, turn off the car and restart it and the problem goes away.
Engine light was up at around 48700mile, diagnosis reading stated "PCV Regulator Valve Performance"
This is a known problem with The Mercedes cars from 2015 through 2018. The Service advisor said this is a know issue with this year, I asked can you do it for free because it is a Merc issue. He said he cannot do it. The cost for this repair is $2500 in Mercedes show room. These should be recalled and repair it for free for the customers.
PCV valve causing check engine light to come on. 50,000 miles on vehicle.
Hello, I have 2016 Mercedes Benz c300(W205). Recently I got a Check Engine Light with P052E71. And the solution is to replace the Crankcase Ventilation Valve/Oil Separator, Intake Manifold. These parts are positioned on the right side bottom of the engine. It was a labor intensive work which required to remove multiple parts to gain access to the oil Separator. Considering the Issue Persists from W205 and Mercedes Benz has not done anything to rectify it, the cost is actually burdened upon the customer.
I was moving my car from one parking space to another space in front of my house. As I was pulling into the new space, I stopped to check the position of my car. As I lifted my foot off the brake, the car unexpectedly started to lurch forward. When I released the brake pedal, the car suddenly accelerated and proceeded to jump the curb and run into the front of my house. Luckily, no one was injured. There was some damage to the exterior of my house. I have reported this issue to the car manufacturer, Mercedes Benz. In response, they have opened a case to research it further.
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).
After locking car and walking away, engine starts, lights go on, and car doors become unlocked.
The contact owns a 2016 Mercedes-Benz C300. The contact stated that after turning off the vehicle and locking the doors; after a while, the vehicle would independently unlock the doors and then start up without driver input. The vehicle was taken to the dealer however, the mechanic was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 43,000.
Crank case ventilation system malfunction
The code P052E reads at only 49.000 miles....Mercedes wants $3000.00 to repait ir (replace PCV valve ). Car runs and drives normally....its probably a faulty sensor. I have seen a lot of posts with owners havins same issue.
The contact owns a 2016 Mercedes-Benz C300. The contact stated while crossing a pay toll, she was depressing the brake pedal to the floorboard but the vehicle failed to decelerate and rear-ended into a truck. The contact stated no warning light was illuminated. The contact stated no one was injured nor sought medical attention. The contact stated there was no need to call and report the incident, no police report was filed. The contact stated she continued driving to her destination. The contact stated when she stepped out of the vehicle, she noticed the bumper, the grill, and the Mercedes-Benz logo and bracket were fractured. The contact took the vehicle to a local dealer, where it was diagnosed with needing the brake pads, the rotors, the bumper, the Mercedes-Benz logo, and the bracket to be replaced. The vehicle was repaired. The contact asked the dealer what was the cause of the failure but the dealer did not have a diagnosis for the failure. The manufacturer had not been informed of the failure. The failure mileage was approximately 49,900.
P052E emissions code
I was driving my 2016 MB C300 on a clear sunny day (approx 85 degrees outside) going around 50 mph when out of nowhere my pano sunroof exploded (extremely terrifying sound might I add!)! I never open my sunroof and it did not have any chips or cracks at all so there is no explanation. Almost the entire sunroof shattered! Mind you I was driving on an open road (no trees, overpasses, bridges, etc). No cars in front of me and closest car was around 1/4 behind me. Shards of glass fell on top of me and went all over the interior of my car. I almost drove off the road and could have gotten glass in my eyes! After inspecting, it almost appears as if the glass exploded outwards. This is a major safety concern and needs to be addressed ASAP by Mercedes Benz before someone gets killed!
Check Engine light came on. Upon running the scan from three different reputed repair shops, they show same P052e Positive Crankcase ventilation valve replace message. It first came two months back, reset the code but it still came up.
Failure in the performance of the Crankcase Ventilation Regulator valve, research online indicates this is a very common issue especially in w205s. Mercedes has omitted this from their gasoline powered, emissions control warranty, but is listed under the BLUtech/ Diesel warranty. The car will fail the emissions test, and Mercedes Models have a recurring problem with this part which is charged out of pocket once vehicle warranty is up.
Check engine light and error code P052E - Positive Crankcase Ventilation regulator Valve Performance. Within a year of having the same error code repaired using warranty, I'm again getting the same error code. This is a very expensive repair costing upwards of $2000 as per dealer and I'm having to do this repair again. This should be some kind of manufacturing defect and needs to be recalled.
exterior fixed front roof panel cracking and causes potential roadway dangerous situation if pulls off roof while driving
When I go to put my car in reverse, or drive the gear control is malfunctioning and I’m afraid this can be deadly or cause serious injury.
- CRANK CASE VENT VALVE malfunctioned, it was available for inspection upon request with fee - It made oil burning smell - The problem has been confirmed by a dealer and replaced with an expensive fee - Engine check light was on
The vehicle lost power on the Freeway, coasted the off-ramp, and came to a stop, the dealership after describing the issue said that it sounded like a bad piston. Said they have had a couple come in with the same problem. Their diagnosis was a bad piston a day later. The mileage is less than 50,000 miles and the car was driven daily to work 4 miles each way. There were no warnings or symptoms of failure prior to happening. The warranty on the vehicle has expired on 7/1/2021
Check engine light Crankcase ventilation valve failure Mercedes dealer diagnostic
Around the 58,000 mile mark my check engine light on my 2016 Mercedes C300 4MATIC came on . I checked the gas cap, as that can set off the check engine light, and the check engine light went off the next day. 3 days later the check engine light comes on again, so I repeated the steps of taking the gas cap off and putting back on. The light did not go off the next day. 5 days later the light goes off again. This happened several times over a span of 2-3 weeks. I then take my car to be checked with an OBD-II Scanner. It read off every time the check engine light had been on, which was several times. The error code the scanner displayed was "P052E" and a description of "Positive Crankcase Ventilation Regulator Valve Performance". It was the same code multiple times. At this point I did a little research to see if this was something I could repair. While researching the issue, I found that case after case of the very same issue was being reported by owners of cars like mine. I then came across a post that said they had reported the issue to NHTSA and was told that it was such a widespread issue that if "A few more cars are reported to have this issue then a recall would potentially be issued because of the amount of cars that are having the exact same issue at very similar mileages, and it is a very expensive repair. I just feel that this is too common of a problem by the same cars, at the same mileages from the same Manufacturer.
Fuel leak from fuel lines from high pressure fuel pump. This is a common problem for C300s from 2015 to 2019, especially in cold weather. Fumes in cabin and fire risk in engine compartment.
Data synced from NHTSA on May 4, 2026