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 4 of 6

Jul 11, 2022EngineFuel system

PCV valve

NHTSA ODI 11473344

Jul 7, 2022Engine

check engine light p052e71 the valve for the crankcase ventilation has malfunctioned, and the actuator is blocked. Replaced the crankcase vent valve assembly 59k mileage when this issue occurred.

NHTSA ODI 11472681

May 19, 2022Engine

Check engine light came on and gave code P052E PCV Regulator Valve Performance

NHTSA ODI 11465331

May 16, 2022Engine

Cracked cylinder #1. Causes rough idle, loss of power and lots of white smoke out the tail pipe. This is dangerous for anyone behind the car trying to see through the smoke then loosing power and other vehicles almost hitting me. Mercedes know they are defective but because of the large cost associated with repairing them they will not fix.

NHTSA ODI 11464848

Apr 15, 2022Engine

Cylinder #1 losing compression. Onset acute after exiting freeway. Car lost power. Engine warning light turned on. Independent repair shop advised compression problem in Cylinder #1. Dealer then inspected and advised there was compression loss in Cylinder #1. Dealer recommended engine replacement (not repair). The car only has around 46,000 miles and is a 2015 model.

NHTSA ODI 11460977

Apr 8, 2022Engine

The crankcase ventilation valve has gone out on my car. This is a continual problem with these vehicles at low mileage. Mercedes Benz should recall the part for repair as they stated it could damage the engine.

NHTSA ODI 11460195

Mar 23, 2022Engine

PCV (Positive Crank Ventilation) error fault. Error message keeps coming and is affecting a large number of vehicles.

NHTSA ODI 11458079

Mar 16, 2022Transmission & drivetrainEngine

MY VEHICLE'S Positive Crankcase ventilation valve NEEDS REPLACING. AFTER RESEARCHING THIS ISSUE FOR A WEEK IM LEARNING THAT THIS IS A VERY COMMON ISSUE WITH MY VEHICLE'S MAKE MODEL AND YEAR AND IS LIKELY TO OCCUR MORE THAN ONE TIME IN THE VEHILES LIFETIME. THE PROBLEM HAS BEEN CONFIRMED BY AN INDEPENDENT SERVICE CENTER I WAS MADE AWARE OF THE ISSUE BY MY VEHICLE'S CHECK ENGIN LIGHT

NHTSA ODI 11456933

Mar 10, 2022Engine

I keep getting a litany of warnings on the dash.

NHTSA ODI 11456242

Mar 8, 2022Engine

This vehicle has a known issue of the timing chain needing replacement around 80,000 miles. When I hit approx. 78,000 miles i started hearing strange sounds and issues with my vehicle starting so I took my vehicle to a local mechanic and he said that the timing chain needs to be replaced. he also stated that there should be a recall on this issue as there has been a recall on the same vehicle for the same issue just a different year which has the same exact engine therefore this year of vehicle should also have the recall applied for the timing chain to be repaired. This issue is causing engine problems and will eventually lead to the engine completely blowing at any time now.

NHTSA ODI 11455690

Mar 8, 2022Engine

I got a P052E code on my car which means a faulty crankcase or PCV valve. After doing some reading it seems to be a super common problem.

NHTSA ODI 11455780

Mar 4, 2022Engine

Long story short, I own a 2015 C300 Mercedes with 59,500 miles I was driving on the street when my engine started shaking so rough and my car lost power. I panicked and pulled over and drove 10mph all the way home. My vehicle would shake rough, couldn’t exceed 10mph and would make loud noises. I take it to the Keyes Mercedes dealership and they tell me it’s a cracked piston. I couldn’t believe it because I only have 59k miles. I have my vehicle records so I have been up to date on my maintenance. They dissembled my engine and couldn’t find the cause to the failure but found the cracked piston in cylinder #1 and damage to the cylinder walls. They recommended to replace complete engine and it will cost me about more than $18,000!! The piston falls under Mercedes 7 year/70k miles emissions warranty and yet they deny coverage. After doing lots of research I come to find out that I’m not the only victim that has suffered the exact damage. People that also own a Mercedes c300 and other models are now without a vehicle and looking at a repair of $18k+ and making a car payment for nothing. This has caused us stress, inconvenience, and damage to our mental health. Keyes Mercedes located in Van Nuys is also aware of the common cracked piston issues on their vehicles. In 2 days I mark 4 months without my car. Please help!!

NHTSA ODI 11455271

Feb 4, 2022EngineFuel system

Car has 51,000 miles , no check engine light or any other warning light .driving in on the freeway at 70 mph when I hear a pop sound and my car loses power , I pushed on the gas and it started to shake violently and I panicked as the construction on the freeway was not allowing drivers a shoulder to pull over on . I was lucky enough to be driving at 2am and with the construction going on , drivers were already slowing down . My car also started blowing a thick white smoke through the back exhaust that could have made it harder to see that late night as it was already foggy here in California . At first I didn’t realize I was smoking through the back until my car began smelling like burnt oil . I wasn’t able to get off the freeway until the next exit all while thinking that my car was going to explode from the smell of the burning oil . When I pulled over and got out of the car I made sure I didn’t see any fire and then I waited to let it cool down , opened the hood and saw oil everywhere . I had it towed to Mercedes and I got the problem and the estimated cost to repair it . The problem turned out being a cracked piston in cylinder one , when it cracked it allowed oil to mix with the gasoline and that’s what was causing all the white smoke out the rear , the burnt smell was from the oil that was leaked all over my engine getting too hot from the engine. I found out a few days ago that Mercedes’ has a technical billeting regarding a faulty wrist pin that was causing the pistons to eventually crack . In the bulletin the faulty pin problem is fixed by replacing all the pistons and adding a upgraded pin and many other parts . So there are many other drivers that are experiencing this and driving with faulty wrist pins . Prior to all this happening the car always made a tap tap tap sound from engine and Mercedes’ said it was normal for 4cylinder turbos to make this sound, sounded like a diesel . But it turned out being from the loose wrist pin . Mercedes lied to us . THE CONSUMER REQUESTED THAT MERCEDES BENZ VEHICLES, WITH THE M274 ENGINE, BE INVESTIGATED. THE CONSUMER STATED THE VEHICLE SUDDENLY LOST POWER. THE CONSUMER STATED THE CAUSE MAY BE DUE TO A WRIST PIN THAT IS THE WRONG SIZE.

NHTSA ODI 11450360

Jan 21, 2022Engine

The contact owned a 2015 Mercedes-Benz C300. The contact stated that while idle, the engine would vibrate with an abnormal sputtering sound coming from the engine. As the failure persisted, the check engine warning light illuminated. The contact had initially taken the vehicle to a dealer and the spark plugs were replaced; however, the failure persisted. The vehicle was returned to the dealer and a diagnostic test was performed, and it was discovered that an engine cylinder had blown. The vehicle was diagnosed with engine failure and the contact was provided an estimate for the repair. The contact then spoke to an independent mechanic who informed her that the failure was a common failure for her model vehicle. The manufacturer was also notified of the failure and a case was filed. An email was sent to the manufacturer and the contact was informed that no further assistance could be offered. The vehicle was not repaired. The failure mileage was approximately 50,900.

NHTSA ODI 11448341

Jan 21, 2022Engine

The wrist pin is defective in early engines during manufacturing. It is not safe to operate the vehicle because at any time without any warning this can cause fatal damage to the engine - piston crack resulting in total loss of control even at high speeds on the highway. Numerous complaints were filed on NHTSA regarding cracked pistons most likely related to this wrist pin manufacture defect. The problem is acknowledged by M-BENZ (NHTSA ID Number: 10058545), and starting around April 20 2015 M-BENZ started to install modified wrist pins to prevent future failures, but they did not address existing faulty wrist pins. The vehicle was always serviced at the official MBENZ Dealer service and was under comprehensive inspection multiple times but the issue was never acknowledged by the service technicians during the warranty period even though the issue existed since manufacturing and instruction of how to diagnose was distributed between service technicians via Manufacturer Communication Number: LI03-10P060916 in 2015. When the M-BENZ Delear service technician finally confirmed the issue, the vehicle was already out of warranty and there is a hefty price to a customer to fix this manufacturer defect that should not have been there in the first place. There are no warning lamps, messages, or other easily detectable symptoms of the problem prior to the failure. The issue can be diagnosed under very special conditions described in Manufacturer Communication Number: LI03-10P060916 For most drivers, it's hard to diagnose that something is wrong and easily mistaken for normal operation noise of the engine

NHTSA ODI 11448391

Jan 6, 2022Engine

Without any warring or indication my engine would start making bad noise then light comes on to check engine as the motor fails and car shuts off. This is while driving and has happened two times now. Both times I find it’s due to spark plug failure and pieces of the plug go throughout the engine and severely damage. First time this happened at 82,000 miles and was covered by warranty. Now this has happened again on the new engine with 81000 miles on it. I seen many forums on this issue. This time it’s not under warranty and it’s $18000 to fix. Mercedes Benz w205 engine seems to be notorious for spark plug failure in cylinder 1 as well as piston cracking. The first time this happened was October 12th 2019 and the warranty work was done at fletcher Jones Mercedes Benz of Newport Beach

NHTSA ODI 11446555

Dec 17, 2021EngineFire

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving approximately 50-60 MPH, the #1 piston cracked. The contact stated that while his daughter was driving, the vehicle was shaking and smoking. The check engine warning light illuminated. The vehicle was towed to an independent mechanic and the contact was informed that the #1 piston was cracked, engine cooler, P0301 cylinder #1, P219 solenoid failure. The vehicle was taken to another independent mechanic and the engine was replaced. The contact called the local dealer, but the vehicle was not diagnosed or repaired. The manufacturer was notified of the failure, but no further assistance was provided. The failure mileage was approximately 105,102.

NHTSA ODI 11444200

Oct 14, 2021Engine

Check engine light came on. Code P052E. Had this code in 2018 and the pcv valve and line were changed. Currently has the same issue 3 years later. This is a very common problem with mercedes that have this engine.

NHTSA ODI 11436743

Sep 30, 2021Engine

The engine stalled at idle numerous times when at a stop light or stop sign. This was dangerous as the other cars could have ran into my car in anticipation that I should be moving with traffic. The car was taken to the Mercedes Marin dealer service center and diagnostic was done indicating a cracked piston in cylinder one was causing loss of compression and could also cause engine failure at speed if not taken care of. Check engine light DID NOT come on. During research on repairs for this issue, it became apparent that Mercedes Benz is aware of this issue in many of its engines of this model and year, but did nothing to remedy the situation or the underlying manufacturing defect that causes the cracked piston. In addition, Mercedes is unwilling to cover the cost of repair or replacement (car has only. 49,000 miles, but is out of warranty due to age).

NHTSA ODI 11434943

Jul 5, 2021Engine

In March of 2020 I was driving home from work. I stopped at a red light. When it turned green, I proceeded to step on the gas. My car started making noises and shaking as I drove. My check engine light came on. I was able to pull over without incident. My vehicle has under 48k miles on it! I had it towed to a Firestone facility by my house. They replaced spark plugs and ignition coil 1 and 2. They said it was still severely misfiring. Cylinder 1 must have internal damage and should be towed to the dealer. They gave me a spark plug they removed that had significant damage to the top part. They said something must have impacted it with significant force. I then had the vehicle towed to a Mercedes Benz Dealership. They said they inspected with a scope and found piston material missing, can see ring exposed and have damage to cylinder wall. Will need to replace engine, turbo charger, cat converter intake manifold to repair. They wanted $18k to repair. I did some research and found out that the 2015 Mercedes C class was the first year they switched from 6 cylinder to 4 cylinder turbo charge engine. These models have had a significant amount of engine problems and failures, the manufacturer is aware of. Many of these occurred in cylinder 1 along with wrist pins issues and others. I found my situation wasn't unique. I then filed a complaint with The BBB in Georgia. MBUSA offered me $3k towards the repair or purchase of a new vehicle. I declined the offer. I only wanted my vehicle repaired. I wasn't alone in this situation. These issues are easily found online. My vehicle has since been sitting in my driveway for almost a year and a half. I've been making my monthly car and insurance payments on a vehicle I can't drive. I recently went to the Mercedes dealership and they will give me $5k for the vehicle towards a trade, leaving me with $15k negative equity towards the purchase of a vehicle. Mercedes should stand behind their products and do the right thing

NHTSA ODI 11423487

Jun 28, 2021Engine

I was in middle line on I-5 SB San Diego doing 40-60MPH when my car suddenly started to shudder, shake and smoke came from the exhaust. The car lost power and the check-engine light came on right away. I was told that Cylinder 3 lost pressure, that the engine wall was damaged and that possibly the piston and wrist pin are cracked. My car has only 66K miles and the Mercedes Benz dealership is telling me that I need a new engine that will cost $19,000. After doing some research I have found out that I wasn't the only one with this issue. I have listed an example here: "HERE IS A MAJOR ISSUE WITH THE 2015 M274 MERCEDES ENGINE REGARDING THE WRIST PINS. MERCEDES HAS ISSUED NUMEROUS INTERNAL SERVICE BULLETINS ABOUT THE ISSUE. THE ENGINES WERE MANUFACTURED WITH WRIST PINS WITH TOO MUCH TOLERANCE THAT SLAP AGAINST THE PISTON WHEN OPERATING THAT COULD LEAD TO PREMATURE ENGINE FAILURES. THERE ARE HUNDREDS OF COMPLAINTS ON ONLINE FORUMS OF PREMATURE ENGINE FAILURES (PRE 100K MILES)." MBUSA requested from me proof that the car was serviced on time and with the correct parts. Once I was able to prove everything they told me that they were sorry but I still need to pay for everything. They did offer a "10% good-will discount". I wish they told me when I was buying a car that after every 6th oil change I will need a new engine. PLEASE MAKE MERCEDES MAKE THIS RIGHT AND FIX THE AFFECTED CARS THE RIGHT WAY.

NHTSA ODI 11422534

May 21, 2021Engine

check engine light and check oil light came on in rush hour traffic in atlant during rush hour. Car started sputtering and finally made it to the shoulder of the interstate and oil was low on the dip stick. I added oil and a day later same thing. Took it to the dealer and cracked piston in #1 cylinder service guy said about 3 to 6 a day on this year benz.

NHTSA ODI 11418053

May 13, 2021Transmission & drivetrainElectrical systemEngine

THE CAR HAS INTERMITTENT STARTING ISSUES MORE NOTICEABLY DURING ECO START / STOP PROCESS. WHEN CAR DOES AN ECO STOP AT RED LIGHT OR STOP BUT IT IS UNABLE TO RESTART CONSISTENTLY (10-20% FAIL RATE). ALL DASHBOARD LIGHTS COME ON AND CAR IS STALLED. CAR CAN ROLL IF ON A HILL. CAR CAN BE RESTARTED BY TURNING CAR ON AND OFF MANUALLY. ONLY ERROR CODE IS P1CE200 BUT THE MANUFACTURER SUGGESTED STEPS DO NO SOLVE PROBLEM. BATTERY, AUXILLARY BATTERY, STARTER, VOLTAGE DIP LIMITER, BATTERY SENSOR, STARTER RELAY WERE REPLACED. DELEAR UNABLE TO FIND PROBLEM AND SAYS ALL SOFTWARE IS UP TO DATE.

NHTSA ODI 11416414

Mar 23, 2021EngineDriver assistance

CHECK ENGINE LIGHT KEEPS COMING ON/ FOWL ORDER COMING FROM AC UNIT/ LOUD GAS SMELL WHEN START IGNITION IN THE MORNING

NHTSA ODI 11404560

Mar 17, 2021Body & structureEngine

TL* THE CONTACT OWNS A 2015 MERCEDES-BENZ C300. THE CONTACT STATED THAT THE VEHICLE WAS RECENTLY IN AN ACCIDENT. THE VEHICLE WAS REPAIRED AT GERBER COLLISION & GLASS (102 CORPORATE PARK DR, HENDERSON, NV 89074) HOWEVER, WHILE LEAVING THE COLLISION CENTER, THE CONTACT HEARD A LOUD KNOCKING SOUND COMING FROM UNDERNEATH THE VEHICLE. THE CONTACT ASKED THE COLLISION CENTER TO INSPECT THE VEHICLE FOR THE SOUND HOWEVER, THE COLLISION CENTER DECLINED. THE CONTACT THEN TOOK THE VEHICLE TO MERCEDES-BENZ OF HENDERSON SERVICE CENTER (925 AUTO SHOW DR, HENDERSON, NV 89014) TO BE INSPECTED. THE VEHICLE WAS NOT YET DIAGNOSED NOR REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 55,321.

NHTSA ODI 11403557

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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 →