Home · 2017 Mercedes-benz C-class Hybrid · Complaints

What 251 owners told NHTSA about the 2017 Mercedes-benz C-class Hybrid

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 (251)Crash / fire / injury (19)Engine (82)Electrical system (35)Fuel system (35)Body & structure (26)Seat belts (26)Airbags (18)Steering (15)Transmission & drivetrain (15)Visibility & wipers (11)Wheels (6)

82 of 251 complaints match · Engine · clear filters · page 2 of 4

Oct 27, 2023Engine

I took my vehicle to the mechanic due to the check engine light been on. The diagnostic came back to be that "The valve for crankcase ventilation has a malfunction. The actuator is blocked." As per mechanic this has to be replace but cost around $ 2,000 plus.

NHTSA ODI 11552323

Sep 24, 2023Engine

P520E code which is caused by a crankcase ventilation issue. The fix costs upwards of $2000. It seems to be a common issue with Mercedes vehicles with 4 cylinder turbos and should be a recall on this system.

NHTSA ODI 11546254

Sep 17, 2023Engine

Piston one issue. I bought this car from an auction and according to the record on the car the previous owner had problem with piston one and low compression in that piston. After performing some research it looks like Mercedes’ Benz c300 m274 is riddles with this issue. It’s all over the internet and I don’t know why Mercedes is not taking responsibity for this. This car has less than 70000 miles and the engine is locked from the cylinder. Thank you

NHTSA ODI 11545079

Sep 12, 2023Engine

The Crankcase Ventilator Actuator has malfunctioned, resulting in the Check Engine light showing up. The MB C300 4matic 2017 vehicle is at 40,200 miles as of [XXX]. Lot of other MB owners have reported same issues. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11544080

Sep 2, 2023Engine

My c300 2017 only had 55k and suddenly the engine light on, when I check it show that I need Positive Crankcase ventilation valve replace. it cost $2300.

NHTSA ODI 11542275

Aug 27, 2023EngineFuel systemLane Departure

Check engine light came on, a day after purchasing from dealer. Mileage at 55k. Check engine light code was p052e71, confirmed from 2 auto repairers. One was Mercedes Benz who quoted me $3900 to repair. In the Mercedes Benz booklet warranty says emission related repairs are covered for 15 years/150k miles for hybrid vehicles.

NHTSA ODI 11541047

Aug 19, 2023Engine

Piston crack in Cylinder 1

NHTSA ODI 11539587

Aug 1, 2023EngineFuel system

My Mercedes Benz stopped working. The mechanic shared it involves the: fault valve for crankcase ventilation has malfunction.

NHTSA ODI 11535656

Jul 15, 2023Engine

Unknown

NHTSA ODI 11532510

Jul 8, 2023EngineFuel system

Code PO52E

NHTSA ODI 11531076

Jul 7, 2023Engine

check engine code P052E : Positive Crankcase Ventilation Regulator Valve Performance. This is a common problem in all mercedes 2015-2020 and it cost about 2000 to repair. This should be a recall.

NHTSA ODI 11530881

Jun 1, 2023Engine

My car is throwing the error code P052E. It keeps going on and off.

NHTSA ODI 11524946

May 30, 2023Engine

Egine light on need to replace clogged Pcv value at 48,000 miles. Seems like this part needs a recall

NHTSA ODI 11524397

May 9, 2023Engine

I recently had to repair a part of my engine with the code P052E. It specifically was "The Valve for Crankcase Ventilation. It stated it was malfunctioned and that the actuator is blocked. It could have caused my engine to fail and my car to stop at any moment putting myself and others at risk. There is a large amounts of consumers with the same vehicle that complained about the same issue. It was inspected by the Mercedes Benz dealership. The only warning was that my check engine light was on.

NHTSA ODI 11521093

Apr 17, 2023Engine

A very common problem with mercedes. PCV ventilation valve. Fault code P052E

NHTSA ODI 11517369

Apr 5, 2023Engine

P052E positive crankcase ventilation regulatory valve Part number 274-090-17-29-80

NHTSA ODI 11515645

Apr 4, 2023Engine

I have a 2017 C350E with 69K miles. Dealer wants $2900 to fix the Crankcase Ventilation Valve. The part that needs to be replaced costs about $600 with lot of labor time involved (~$2500). The part number is 274090560084. The C350E has a 15 year emissions control warranty in California that is supposed to cover "all" emissions control related parts, but Mercedes Benz USA doesn't seem to think this is part of the emission control system. I have done some research and it appears that "crankcase ventilation" is a necessary function of the engine because "blow-by" fumes would build up in the crankcase if it were not ventilated. These "blow-by" fumes used to be vented straight to the exhaust in older cars, but in the 1960's they started to recirculate them with the PCV system back into the intake manifold to limit the emissions. The function of this part seems to do the same thing a PCV system.

NHTSA ODI 11515411

Mar 11, 2023Engine

Code P052E costing me over $2500 to repair. I’m not the only one dealing with this problem and my car only has 58k miles and it’s a 2017. Should be recalled considering the part being defective.

NHTSA ODI 11511341

Mar 7, 2023Engine

Positive Crankcase Ventilation (PCV) Can cause problem to the engine. Check engine light is on, car have been scanned. This happen one week ago. There’s no recall for this and happen a lot many Mercedes Benz causing problems on engine and is not on warranty or any other recalls

NHTSA ODI 11510678

Mar 7, 2023Engine

my 2017 Mercedes C300 experienced what appears to be a very common engine fault with the W205 engine. It involves the "PCV" valve and the engine code fault is P052E. When this fault occurs the engine will stall and sputter. My wife and daughter were in my car last week and it stalled at an intersection which could have resulted in an accident, but luckily the school crossing guards were there to stop traffic and allow her to restart the car and get to the side of the road. The check engine light had previously been on and off for sometime so I had my local Mavis check what the light was on for and they gave me the fault code. I did not think it was anything that serious because the car ran fine. The car was towed today to Mercedes to officially diagnosis the problem

NHTSA ODI 11510714

Mar 2, 2023EngineFuel system

I have a mercedes c300 2017 and recently I was driving my car and the check engine light came on all of a sudden so I took it to my local shop to diagnose it they told me it was the PCV valve, so I called mercedes and they’re telling me that this is not covered and of course my warranty is no longer covered I have about 63k miles on the car. Mercedes is saying they don’t have a recall for this but I’ve googled around and multiple people are saying the same issue happened to them around the 55-65k range. It’s super frustrating that this doesn’t flag a recall.

NHTSA ODI 11509860

Feb 7, 2023Engine

Engine code P052E - PCV REGULATOR VALVE PERFORMANCE. Common faulty Mercedes Benz part integral to the car. Just took in the car to MBSeattle.

NHTSA ODI 11506123

Jan 28, 2023Engine

In my family we have 2 mercedes benz cars one 2017GLC300 and other 2017 C300 4matic and both of the cars have the same issues. Check engine with code P052E. And after talking to friends and mechanics it appears that this issues to be almost on every mercedes car of this engine since both of the cars that are in my family have the same engine components. I request that it should be recall so mercedes benz will repair those issues under warranty. Thank you

NHTSA ODI 11504121

Jan 10, 2023Transmission & drivetrainEngineFuel system

I purchased my 2017 C300 class Mercedes-Benz ("MB") in May 2021 from a used car dealership in Mobile, AL. At that time it had 36,000 miles. Less than 2 years later, on or about 12/15/22, as I was driving, the MB suddenly and without warning began to vibrate violently and immediately lost power. The car had @54,000 miles on it. I routinely drive interstate to and from work and had just gotten off of the interstate. I was lucky that I was driving at a low speed when this happened; otherwise, a serious accident could have resulted. I took it to the local MB dealership which told me that the car failed a compression test in the #1 cylinder and that the engine would have to be replaced. Subsequent research on the cause of this total engine failure with low mileage revealed that this engine has a chronic piston defect that damages the #1 cylinder, causing it to lose compression, and that MB has known about the defect for many years, an issued an internal bulletin about it. MB has not alerted the public nor instigated a recall. I was not informed by MB at any time that the C300 class engine had a chronic piston defect that would damage the #1 cylinder which would, in turn, cause the engine to lose power and the vehicle to vibrate and shake, creating a dangerous diving condition under all circumstances, but especially if the car was being driven at speed on a federal interstate highway. Despite demands by me and others, MB refuses to responsibly address the issue. The driving public is, and remains, clearly, in great risk of harm due to this defective engine and associated power train issues. It is patently unreasonable for MB to produce and market such a unsafe, dangerous and defective product that poses an unreasonable risk of harm to its customers and others when being used as it was intended. I understand that the NHTSA has opened an investigation on this defect and wish for my voice to be heard on it. Please contact me [XXX] for further details. INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).

NHTSA ODI 11500998

Jan 4, 2023Electrical systemEngine

Hey good morning. There’s been a been a system failure. P052E Positive Crankcase Ventilation Regulator Valve Performance. Warning message I got was the engine light showed

NHTSA ODI 11500059

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Working with the data? Download all 251 complaints as CSV · fetched from NHTSA July 25, 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 2017 Mercedes-benz C-class Hybrid verdict →