Home · 2015 Mercedes-benz C-class Phev · Complaints

What 433 owners told NHTSA about the 2015 Mercedes-benz C-class Phev

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (433)Crash / fire / injury (13)Engine (134)Fuel system (75)Body & structure (72)Electrical system (54)Steering (28)Suspension (28)Airbags (26)Transmission & drivetrain (23)Visibility & wipers (17)Brakes (10)

134 of 433 complaints match · Engine · clear filters · page 2 of 6

Oct 3, 2023Engine

The valve for crankcase ventilation has a malfunction. The actuator is blocked. Seems like its a common problem for all mercedes C300 ~2015 models. The part should be recalled.

NHTSA ODI 11547899

Sep 21, 2023Engine

After getting gas my check engine came on steady. Stayed on until cleared. After getting gas a 2nd time check engine light came on again, stayed on, but went out. Then after getting gas a 3rd time, check engine light came on again. Checked by a local Mercedes shop, code showed intake line oil separator bad. Owned this car for 7 years, never had an issue like this. 50,516 miles currently. Quote for repair is high, over $1000 dollars. All episodes of check engine light have occurred in a 4 week time frame.

NHTSA ODI 11545905

Sep 17, 2023EngineFuel system

P052E PCV value problem Google search results show this is a very common problem, and despite being a component of the vehicle emissions system, Mercedes is refusing to repair under the emissions warranty.

NHTSA ODI 11545073

Sep 11, 2023Engine

2015 MB C300 Check engine light came on, appointment scheduled to check issue before it went to the mechanic had a safety issue when accelerating to turn in a seven lane busy intersection the car lost acceleration and missed, running rough for a few seconds then recovered in time for me to get out of the way of the 45-50 mph oncoming traffic. Issue is P052E positive crank case ventilation valve which is going to cost $2200 to fix. Car has just over 60k miles on it and this is a known issue for YEARS on multiple MB turbocharged 4cl. I could have been t-boned if the acceleration hadn’t recovered. Does someone have to get killed before MB recalls the vehicles? 60k miles is not a lot of mileage for a car 8 years old that has had all its scheduled maintenance.

NHTSA ODI 11543843

Sep 6, 2023Electrical systemEngine

ESP CONTROLLER NON FUNCTIONAL

NHTSA ODI 11542815

Aug 29, 2023BrakesEngine

My crankcase vent valve needs to be replaced also EBD traction abs module which alone cost over 1500 for part needs to be replaced

NHTSA ODI 11541416

Aug 28, 2023Engine

2015 made C399 PVC change cost more than $1,000. Almost every driver has this issue.

NHTSA ODI 11541265

Aug 25, 2023Engine

MB 2015 C300 4MATIC. Check engine light came on. Went to a Mercedes Mechanic and they read the code as PO52E71. Crankcase Vent Valve Malfunction. This was reset and two days later the check engine light came on again with the same error/fault code being read. This seems to be a common issue for this manufacturer and is a very expensive repair. In the even this is a common issue, I wanted to report this for the record.

NHTSA ODI 11540787

Aug 16, 2023Engine & coolingEngine

The contact owns a 2015 Mercedes-Benz C300. The contact stated while driving 25 MPH, the check engine warning light illuminated. The contact veered to the side of the road. The vehicle was towed to an independent mechanic, where the diagnostic test retrieved code: P052E, and it was determined that the positive crankcase ventilation (PCV) valve had failed and needed to be replaced. The vehicle was not repaired. The dealer and the manufacturer were not notified of the failure. The failure mileage was approximately 125,000.

NHTSA ODI 11538997

Jul 25, 2023Engine

Engine crankcase vent valve failure. common issue with these vehicles. can cause fire

NHTSA ODI 11534259

Jul 25, 2023EngineFuel system

Just got my car from the mechanic on 7/21/23 and it through an error code as I drove home. Towed back snd mechanic stated I need to replace the crank case vent valve assembly. Further stated that they keep in stock because it happens often. Error code P2188

NHTSA ODI 11534426

Jul 18, 2023EngineDriver assistance

Engine Crankcase (pcv) Problems on Mercedes Benz C300 and harness issue. I’ve noticed this is a very common issue many owners as myself have experienced and no action for a recall.

NHTSA ODI 11532943

Jul 14, 2023Engine

I have 65000 miles on my car. It is 2015 Mercedes C300. My Engine light came on. Found out that Crankcase Vent Valve needed to be replaced. Cost me 1200 dollars. It appears that lot of Mercedes C series cars have the same problem. I feel that Mercedes should pay for it.

NHTSA ODI 11532242

Jul 1, 2023Engine

Engine check light code: P052E Crankcase Ventilator / oil separator. Huge problem could cause the engine to stall while driving. Could lead to an accident if you are trying to merge on the highway and the engine stalls out.

NHTSA ODI 11529922

Jun 28, 2023SuspensionEngineDriver assistance

Mercedes 2015 C300 crank case ventilation hose has a defect and it is well-known to the manufacturer. This causes recurring engine and exhaust problems for a large number of car owners, and it should be part of a recall.

NHTSA ODI 11529358

Jun 22, 2023Engine

My 2015 Mercedes c300 only has 39k miles and suddenly the engine light on, when I check, the dealer it shows that I need Positive Crankcase ventilation valve replace. it cost $2300. This is basically a brand new car and needing this repair every 30k is a joke please issue a recall and have Mercedes held responsible

NHTSA ODI 11528389

May 26, 2023Transmission & drivetrainEngineFuel system

Mercedes Benz via American Service Center in Arlington, VA regarding the service they performed on my 2015 C300 W4 4Door Sedan AWD the following issues have presented: ISSUE: 03MBZZWARN1 ENGINE LIGHT TECH: 901844 PROBLEM: ENGINE HARNESS, ENGINE CONTROL MODULE, CRANKCASE VENT VALVE, AND O2 SENSOR BANK 1 CAUSE: FOUND OIL IN THE ENGINE HARNESS AND ENGINE HARNESS. OIL IS ENTERING THREW [SIC] THE CRANK CASE VENT VALVE. RECOMMEND REPLACING. Approximate miles at the time of this issue: 63,141. Cost of Repair: $8309.58 Yes, the vehicle is available for inspection. Safety concerns: The vehicle is not able to pass an emissions test with the engine light engaged. Per America Service Center in Arlington, VA, which is the only service center that has serviced the vehicle during my ownership, they commented and documented that oil is entering through a vent valve. My additional concerns are: If an odorless fume is passing into the passenger cabin and the vehicle can not pass state emissions these are immediate concerns. The service center advices that I may continue to drive the vehicle. However, I am concerned should the oil fully empty without warning the vehicle may fail while in use on a dangerous roadway due to cause and effect of additional unknown maintenance related operational co-dependent mechanical components.

NHTSA ODI 11524033

May 7, 2023Engine

Crank case breather assembly needed replacement at 31,200 miles. Service mech. Advised the leaking area (oil) could not be repaired since Mercedes does not sell replacement parts and entire assembly needs to be replaced. March advised Mercedes is aware of issue and has redesigned the entire assembly. Cost for part was $400+ and labor to install was $1000. This issue is common as seen on internet and should warrant a recall refund to customers.

NHTSA ODI 11520828

May 5, 2023Engine

Positive Crankcase Valve faulty causing car to buck during moderate acceleration especially when accelerating onto an interstate on an on ramp.

NHTSA ODI 11520609

Mar 31, 2023Engine

My vehicle is a 2015 C300 AWD. One day I was driving on the highway and noticed white smoke coming out of the exhaust. The check engine light came on shortly after as I pulled over. Being that I was less than a mile from my house, I decided to go park the vehicle. I noticed that it was losing power and had problems going above 45mph. Since my vehicle had 99k miles. I took it to my indy mechanic that has worked on the vehicle since it has been out of warranty. When he diagnosed the vehicle, 48 codes came up. He suggested we change the spark plugs and coils, which we did. Didn't fix the problem. Then he suggested we change fuel injector 1, which we did. That didn't solve the problem. I decided to take it to the local Mercedes dealership where they did another diagnostic test. And like many others here, cracked piston/cylinder 1 dead. I'm looking at $18,000 in repairs. I told them no thank you. The car is now sitting in my garage. I really hope Mercedes makes this right with its customers. There is no reason why this many people should be having this exact same problem. Vehicle Symptoms: White smoke out of exhaust Check engine light on Cylinder 1 Misfire Burning Oil Causing loss of power Radio randomly shuts off & went into Anti Theft Mode

NHTSA ODI 11514880

Mar 30, 2023EngineFuel system

2015 C300 Crankcase Ventilation Valve Replacement P052E71 NEED TO BE REPLACED, ENGINE LIGHT COMES ON. ONLY HAVE 37,000 MILES MANY REPORTS OF THIS ISSUE

NHTSA ODI 11514640

Mar 27, 2023Engine

my car is a 2015 C300 class Mercedes-Benz, as I was driving, the car suddenly and without warning began to vibrate and shake violently and immediately lost power. Fortunately I was off the freeway, a serious accident could have resulted. I took it to the the local MB dealership and they told me that the car failed a compression test in the #1 cylinder and that the engine would have to be replaced at almost $17000. Of course, this was beyond warranty, Mercedes know it’s a defective product, they refused to act responsibly. This cracked piston which is a design flaw by Mercedes needs to be recalled, a lot of people are reporting the same issue.

NHTSA ODI 11514065

Mar 26, 2023Engine

The problem is actually a manufacturing defect in the wrist pins. The defective parts are in engines made before April 20, 2015 which is mine. If left unrepaired, it causes premature wear in the cylinder walls. The issue on my car been confirmed by mb dealer.

NHTSA ODI 11513842

Mar 23, 2023Engine

obd2 scanner reported Error Code P052E which seems a very common issues on Mercedes C class 2015 or newer and there is no recall issued by Mercedes Benz yet which points out to possible problems with "PCV Regulator Valve components. There are 100s of post in the forum related to same issue

NHTSA ODI 11513338

Mar 23, 2023EngineFuel system

My son's car was blowing white smoke out of the exhaust and had a sweet burning smell and the check engine light came on. The crankcase vent valve is needing to be replaced on this 2015 C300 Mercedes Benz and many owners of this same type of car (different year) are posting about it. Owners of these types of cars are saying that replacement is happening more than once! That it's a common defect of these cars. My son has less than 100,000 miles (61,000 if that) and this shouldn't be happening. And, it's time someone does something to protect the consumer. Mercedes-Benz dealers are taking advantage of consumers and charging ridiculous prices to replace this part, but the part shouldn't be breaking. It's a safety factor in that it can affect driving, there's risk of blowing valves/valve cap and engines, including loss of the vehicle and nowadays no one can afford to buy a new car or even a used one! Consumers buy what they think is a reliable vehicle but Mercedes isn't taking care of their customers. Mercedes-Benz should be forced to do a recall and replace these faulty parts. Read other complaints here: https://www.benzworld.org/threads/2015-c300-crankcase-ventilation-valve-replacement-p052e71.3047538/page-2

NHTSA ODI 11513522

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Working with the data? Download all 433 complaints as CSV · fetched from NHTSA July 20, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2015 Mercedes-benz C-class Phev verdict →