There are 50 owner-reported engine complaints for the 2016 Mercedes-Benz C-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
fuel lines/ clamps defective causing a fuel leak. vehicle could catch on fire and fumes are extremely strong inside the cabin. issue confirmed by Mercedes dealer, mentioned there is an extended warranty up to 120,000 miles. rejected mine because i was at 120,300 miles. had to pay out of pocket. no warning lights or anything just the really strong smell of fuel and fuel range dropping. this is a very common issue thats known and should be a recall.
Vehicle developed OBD-II code P052E related to crankcase ventilation/PCV system malfunction. Issue causes improper crankcase pressure, rough idle, oil vapor smells, and check engine light. Independent research shows this is a common failure on 2015–2017 Mercedes C300 models. Repair requires replacement of crankcase vent/PCV assembly. This appears to be a premature emissions system failure.
CHECK ENGINE LIGHT appeared on dash at approximately 72k miles. Had code read and diagnosed by certified mechanic and he had an active code P06DA00(this code signifies an electrical fault, open circuit, or high resistance in the circuit for the oil pump control valve on vehicles with two stage oil pump, which can lead to incorrect oil pressure, which can cause engine damage if not addressed). Vehicle was taken to Harriman Mercedes in New York. They did not acknowledge an active code but wanted to diagnose and repair a stored code for a small evap leak, which was rectified with a new gas cap. After prying about the P06DA00 code, they finally admitted it did have a stored code but to ignore it because it had something to do with domestic and foreign car engine computers issues. How do you ignore an active code with a potentially serious engine issue and told to ignore it. I know for a fact that this is a common problem with these 2.0L engines in these cars for many years.
2016 Mercedes-Benz C63 S AMG, M177 4.0L twin-turbo V8. This engine is marketed under Mercedes-Benz's "One Man, One Engine" philosophy — hand-assembled by a single master technician. It failed irreparably at 67,323 miles on a properly maintained vehicle owned by a 14-year Mercedes-Benz customer who has purchased six Mercedes-Benz vehicles. All maintenance performed on schedule with genuine OEM Mercedes-Benz parts at Mercedes-certified shops. At approximately 65,000 miles, check engine light illuminated with cylinder 7 misfire. A Mercedes-certified shop found and replaced a burnt spark plug and all 4 ignition coils with OEM parts. Misfire cleared. Three months later at 67,000 miles, shaking and check engine light returned. All 8 spark plugs replaced with OEM parts. Misfires returned within 100 miles — now on cylinders 1, 3, and 7 — accompanied by violent engine shaking and a fuel smell. Vehicle brought to authorized Mercedes-Benz dealer. Full diagnostic performed including borescope inspection. Confirmed: broken spark plug ceramic and unrepairable piston pitting in cylinder 4 and engine damage. Dealer confirmed engine is not repairable and recommends complete engine replacement. All findings documented on dealer repair order. Vehicle remains at the dealer and is available for inspection. Mercedes-Benz has published at least three Technical Service Bulletins on persistent misfires specific to this engine: LI54.21-P-062006 (multiple revisions — ECU ground faults, borescope protocol anticipating internal damage), LI07.61-P-073583 (post-turbo exhaust clamp failures), LI07.61-P-069688 (intake manifold cracks). Mercedes has acknowledged this defect pattern internally and has not issued a recall. Sudden power loss and violent shaking at highway speed is a direct safety hazard. NHTSA investigation warranted.
The contact owns a 2016 Mercedes-Benz C300. The contact stated that while at a stoplight, the energy saver START/STOP feature engaged, but the vehicle stalled and failed to restart. There were no warning lights illuminated. The vehicle was towed to an independent mechanic who determined that the START/STOP function failed to operate as designed. The mechanic informed the contact about NHTSA Campaign Number: 17V114000 (Electrical System, Engine and Engine Cooling). The local dealer was not contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 56,000.
Positive Crankcase Ventilation Regulator Valve Performance Code P052E indicates a fault in the Positive Crankcase Ventilation Regulator Valve Performance for a predetermined.
I have noticed a recurring issue during the colder months where there is a strong gas smell inside the cabin, and I have also observed fuel dripping into the engine compartment. This issue seems to occur primarily in winter conditions. I was surprised to find that there has been no official recall or service bulletin addressing this concern, especially given the potential safety implications.
PCV fault
Fuel is leaking inside cabin whenever I turn on my heat
Check Engine light...P052E positive crankcase ventilation regulatory valve
This vehicle was 2nd owner via Mercedes CPO. Note I bought this 2016 in 2018 on CPO, so recalls and technical notes were confirmed to be resolved. Had last taken to Mercedes dealership. Vehicle was always running fine until about 64,000+ miles when a check engine light came on while just entering the freeway and the vehicle started shaking violently. Continue to drive the vehicle for a few miles to get to the destination. Had the vehicle towed to the dealership and the dealership declared that cylinder 1 had lost 80% compression and had a cylinder 1 piston crack. This is consistent with numerous claims on Mercedes message boards. Mercedes dealership said that this vehicle was not drivable and was not covered under warranty. Requested $11,000 for single piston repair or $15,000 for full engine rebuild replacement. Please note that M274 engine has this complaint. The engine is apparently a Nissan collaboration designed i-4 turbocharged engine and car is assembled in Alabama. Internal Mercedes technical bulletins talk about piston wrist pins. So Mercedes know there is an issue and they know status on my vehicle. Mercedes dealers have sent me documents on piston wrist pins replacement status. The recommendation is to rebuild or buy new motor. So i have no confidence that an engine rebuild will fix the issue. All oil change maintenance records show proper oil at proper intervals and multi-point inspections. Correct use of premium gas was used. Vehicle had been inspected and given all green remarks on multipoint review before the incident. - Got It ? Requesting investigation as I have 3 vehicles, Toyota (2002), Honda(2008), and YES a Mercedes(2005) with 216K miles. So don't tell me that this is my fault.
error code P052E positive crankcase ventilation regulator valve performance
Code P052E71 Saying the Crankcase is bad. Seems to be an issue with MB.
check engine light p052e positive crankcase ventilation regulator value performance
A couple years back I had an engine light pop up and it was the code P052E which as I’ve done my research and read a lot of forums this is a common problem with the W205 Mercedes Motors. As of today 04/18/24 the engine light came on and I got it diagnosed to find out it is the same problem again. This repair is almost $2000 and it is due to Mercedes faulty manufacturing of the PCV valve. I have read things that say there has been extended warranty on it and a lot of submissions for recalls, that I’m not exactly sure of.
P0952 sensor part not available untill Dec 2024 I have documentation from my mechanic
Pcv valve has gone bad, and it seems like everyone i ask that is mercedes technician they all say these parts are terribly made and always break.
Positive crankcase ventilation regulator valve performance
M274 check engine light P052E71 Crankcase ventilation valve Topic: # LI 01.20-P-076794 crankcase ventilation cylinder head cover WIS-references document # AR01.20-P-9692MRU remove/install oil separator on crankcase.
Error code PO52e crankcase ventilation
Showing 1–20 of 50 complaints
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026