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.
Data synced from NHTSA on May 4, 2026
Had to have crankcase ventilation system replacement at 74k miles. $2,032.98 to replace. Did get a check engine light.
Mercedes C300 4Matic Engine light off. The diagnostic tool showed P052E error, which seems like a common problem with MB C300 models built from 2015. Is there a manufacturer recall for this issue? This warning came a few weeks ago and disappeared by itself shortly. It came again.
CRANKCASE VENTILATION- code: P052E came up and I had just bought from the dealership with 87k miles
My check engine light popped on with code p052E for the Positive Crankcase Ventilation Regulator Valve Performance.
It is such a common issue reported by many 2016 c300 owner who experienced error code p052e bad Pve valve. My car only has 40,000 miles. I think the manufacture should be responsible for a recall. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Ac/heater smells like mold/musty/mildew inside the cabin. Took for the extended warranty but will not honor unless you have proof of cabin filters purchased every year. This is their way of finding a loop of not fixing the issue.
Panoramic sunroof is closing right way. While when i drove air comes in .
I was just driving normally boom engine light comes on take it to the dealership and it come up as crank case vent line which they quoted me 2300$. I think this should be recalled I have seen so many people with the same issue I have actually had someone tell me this was the only major problems with the w205 c300 before this happened. I think it should be recalled because from what I’ve seen it happens to every single c300 just at different mileages. Hopefully this will get a recall because it seems to be a very common issue and should be covered by the dealer.
My car had a problem about starting so I went to see a dealership. They got the job done and charged me $320. I just realized that in the invoice they used recall campaign to cover my car. However, they charged me $320 for no reason. Also, I never got any letter regarding to recall. How did they used recall campaign on my car?? And I recently had a sunroof derailed and they used the campaign again but charge me $2700 for it. And of course my car isn’t in their recall list?? I never got a letter as well
Engine misfire, rough idle, shake when come to red light stop, burnt smell inside cabin, loss of power
Had an oil change at a Mercedes dealership after driving for a couple hours. Check engine was on for a code P052E, being crankcase ventilation system. Had the car diagnosed, cost to repair 1,600 dollars. Went through with repair, the code pop up again (P052E). Having to bring vehicle constantly to Mercedes dealerships.
Fuel smell in cab of car. Strong smell. Took it to dealer and they said they were damp with fuel
I was driving on the local freeway and the strip of glass between the windshield and the sunroof flew off and landed on the pavement behind me. Thankfully the car behind me was far enough away that it didn't hit it--but it could have if it had been. If that had happened I shudder to think what the result would have been. The risk is to those behind me--not to me. The only indication that there was a problem before the event was only a few seconds before the piece flew off when it started to become unattached and the noise from the wind catching it raised my concern. I took the car to Mercedes and had to pay $2300 to have the piece replaced.
Check engine light P052E, PVC valve. Dealer wants $2,500 for this repair and people are complaining that around 30k-50k it does it. Thats ridiculous. My dealer said its a common issue but Mercedes is not issuing a recall.
This auto has approximately 45,000 miles on it and was found to have a fuel leakage issue on a high pressure pump and a fuel hose. Gas smell was very bad and upon inspection, gas was leaking at the hose / pump connection directly onto the engine. I had the defect repaired for a total of $1288.57 and tried to submit the claim to Mercedes. I found out that this issue has been a problem for Mercedes and they have published an extended warranty rather than issue a recall. Mercedes has now declined the complaint and because this seems to be a major issue I wanted to press this with your agency. Please let me know if you would like any additional documentation regarding this matter. Thank you - [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
The PCV Valve/crankcase has broken 3 times on this car with different repairs and parts. This is happening very commonly to these cars and may cause significant safety issues. The code is P052E
Vent valve failed and needs repair. I could smell gasoline from my car weeks up to the check engine light going off. These leaking fumes are a hazard to the population and environment. This problem is quite common on Mercedes forums such as MBWorld. This car was diagnosed at an official Mercedes Benz dealership (New London, CT). The check engine light came on weeks after symptoms started to appear (on and off).
my engine light came on. When I took the car to get diagnosticated message P052E showed.
Engine code P052E has come on at 60k miles. After researching the problems this is a very common problem with the 2016 c300 that mercedes refuses to address. To add insult to injury the part needed to be replaced is a sensor worth 100 dollars but mercedes charges over $2500 because you need specialty tools to get to it. This is a very common problem with owners around 40-80k miles and has no cause other than faulty parts on Mercedes end.
Check engine light comes up. The crankcase ventilation has to be replaced. This is a well known defect in design by Mercedes Benz and there are hundreds of people who have had to replaced the crank case costing thousands of dollar to only have it happen again due to its faulty design. It’s well documented all over the Internet.
PVC valve replacement Engine light off and on Started about 3 months ago
PCV Valve causing contamination and shortening the life of the engine oil.
My car failed smog test due to code P052e positive crankcase ventilation regularly valve. Upon some research, I found that this is very common issue with this car. The repair costs +$2000 before tax at the dealership. Please consider this complain as this issue is very common with this make model and unfortunately many drivers don’t realize that it’s due to faulty system.
Check engine light keeps coming on and off.
The vehicle is not passing emission inspection because the Positive Crank Case Valve/Ventilation failed to work after 48K miles.
Panoramic sunroof pillars/rails detaching while operating vehicle. The front roof panel located between the windshield and the panoramic sunroof may not have been bonded correctly to the vehicle during a prior repair. When operating the vehicle at a moderate speed, the sunroof continued to adjust itself on its own. Belive that there is a risk of the sunroof detaching from the stock plastic rails and that it may not be properly bonded. I do not feel comfortable usuing the Panoramic sunroof for fear of it detaching during driving conditions, putting other motorist and myself in danger.
When i would turn the car to warm up, it has a hefty gasoline smell. Ive seen a lot of people online talk about the same issue. It seems there is a leak somewhere and it is definitely not safe. Especially when i turn on the heat, it just blows the gasoline into my face. This cant be safe and should definitely be fixed
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.
The small plastic located inside the sliding panoramic sunroof explode and the Panasonic sunroof can be open/close or up/down normally but when I hit close it will stop where the broken pieces was and the roof will automatically move back to the fully open position Dealer said need the rail replaced -2057800175 -2057800275 Motor is broken, need to be replaced , he said after saying the roof can go forward and backward, up and down but can’t close completely. I was gullible to believe what the technician and sale guy said. Technically technician can check the voltage and say it for sure if it is broken. Also, a technician already knew that the sliding rail is damaged. He jumped to the conclusion that motor is broken because of sunburn. I have asked my nephew what he would do in this situation. He innocently said he would replace new sliding rails first and try to run if the “alleged motor “ is really broken. If it is broken, he can just switch to a new motor before testing to confirm it working. He wouldn’t decide to buy a new motor that cost $1,400 extra while the old one might be working properly. Anyway, labor with rails and “motor” cost $3500. Then later I learn I’m not alone. How many affected from this defective parts that Mercedes doesn’t sell it separately. Owner must buy 2 set of rails- a left set and a right set. Cost $1100 total. So since the number of affected are pretty high, a few factory in China and turkey decides to produce these little and sell it online for $15-92, glue and lubricants included. -number of owners struggling to find parts https://mbworld.org/forums/c-class-w205/734208-pano-roof-failure-2.html Parts that Mercedes cannot sell it separately so owners have to buy 2 sets left set and right set rails. “Try words like repair sunroof kit for Mercedes “ on eBay only a few couple thousand people buying it in 2022 alone. https://www.ebay.com/p/28019877104 Motor broken? https://c.xtime.com/tvyUiiMwuwoA2L8JXX#/completePage
I have a problem that happened with a trouble code: P052E. It appears for now reason so the problem is in a faulty positive crankcase ventilation regulator valve. It costs a lot and not all the mechanics can do this type of work.
When starting car you can smell gasoline the smell stays while driving
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 on
The contact owns a 2016 Mercedes-Benz C300. The contact stated that the sunroof failed to open. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The failure mileage was approximately 65,000.
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!
Engine light on smells gas constantly tried to change oil that did not work light came back on
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
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.
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;
code P052E on 71000 miles. The crankcase vent valve replacement.
PCV regulator valve
2016 MERCEDES BENZ C300. When I start the car , you smell gas inside and outside of the car. Also the fumes come the vent when the heat is turned on. I have approximately 69,700 miles on my car
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
2016 MB C300 41000 miles. Check engine light went on. Autozone code reader said p052e positive crankcase ventilationregulation value performance.
I have owned the vehicle for only about 4 months. My wife took the car out for a short errand and returned to tell me that the engine light was on. I took the vehicle to AutoZone and had the code ran on their diagnostic computer and it returned a P052E code for “Positve Crankcase Ventilation Regulation Valve Performance”. I have done a lot of research and have learned that this is a common problem and incurs huge financial impact to unsuspecting buyers. Mercedes has even made improvements to the part because of this issue. It’s not safe due to the possibility of oxygen build occurring in the combustion chamber. This part should be recalled and repaired by Mercedes.
There is a strong fuel smells in the interior of my vehicle during a cold start of the vehicle, this is a 2016 Mercedes Benz C300, i called the Mercedes Benz customer service at 800-367-6372 and i was told my vehicle didn't qualify for a free repair. Thank you. Manuel
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.
Car cabin continuously smells like gas after several repairs to the AC. AC was repaired because of mold issue a few months back, however, issues with the AC is always a problem with this car and model.
The contact called on behalf of her daughter who owned a 2016 Mercedes-Benz C300. The contact stated the vehicle had an abnormally strong fuel odor coming from the inside and outside of the vehicle. There were no warning lights illuminated. The contact had not taken the vehicle to the dealer. The vehicle had not been diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 72,000.
(P052e) positive crankcase ventilation regularly valve
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.