Owner-reported complaints naming the engine system, filed with NHTSA
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Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components. Every record below is an owner-reported complaint about the 2017 Mercedes-Benz GLC 300 submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 37 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
The 25 most recent of 37, in the owner's own words
-The malfunctioned component is the Positive Crankcase Ventilation. - Vehicle wanted to stall and did not want to accelerate while in the middle lane on the highway with my family. - Yes it has been diagnosis by certified mechanic - The check engine light turned on at the time of the incident and has been turning on and off ever since.
I was driving and my engine light came on. I ran the code and it came up as P052E which has to do with the positive crankcase ventilation regulator valve. I’ve heard that this part goes out very often on the Mercedes Benz.
Car stalled in traffic due to code P052E PCV regulator valve
The contact owns a 2017 Mercedes-Benz GLC300. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken back to the dealer and the contact was informed that the vehicle was repaired. The contact stated that the dealer had only reset the codes. In addition, the contact stated that the tire pressure sensor warning light was illuminated. The contact stated that the sunroof latch failed to close as needed using the sunroof power switch. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 88,100.
The contact owns a 2017 Mercedes-Benz GLC300. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed, however, the vehicle failed to accelerate as intended. In addition, the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed with a failed positive crank valve. The contact was informed that the positive crank valve needed to be replaced. In addition, the contact was informed that the repair was covered under an extended warranty program, however, the parts were on backorder. The vehicle was not repaired. The contact stated that the failure began in December 2023, however the warranty repair was completed in September 2024, due to parts being on back order. The vehicle was repaired, however, the failure reoccurred. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed, however, the vehicle failed to accelerate as intended. In addition, the contact heard a loud boom that came from the engine. The vehicle was taken to the dealer where it was diagnosed with a blocked turbo. The contact was informed that the turbo needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 94,000.
The contact owns a 2017 Mercedes-Benz GLC300. The contact stated that while at a stop light, the vehicle independently shifted to neutral(N) for approximately 5 minutes. The vehicle failed to release from neutral when the driver shifted the gear shifter. The contact stated that the transmission then released from neutral(N), and the vehicle jolted forward. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who was unable to determine the cause of the failure. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 75,000.
Check Engine light came on. Mercedes Benz authorized service mechanic confirmed it is code P052E - Positive Crankcase Ventilation regulator valve issues that can cause engine to seize while driving. Vehicle has always been serviced regularly at authorized dealer service center. Current estimated Repair and replacement cost $9,700+ . Mercedes Benz authorized Service Center informed that the part is backordered and no estimated date available.
Engine light. Told by Mercedes mechanic it is a code P052E - positive crankcase ventilation regulator valve issues that can cause engine to seize while driving. Repair cost $2,500+
After noticing my engine light come on, I had my vehicle checked out, the dealer informed (after spending $250.00) that the problem is the crankcase ventilation and it's a common problem. It seems the oh so familiar crankcase ventilation system is not working. This is a common problem with the GLC300 and Mercedes Benz needs to correct it. The engine is not being ventilated properly and the overwhelming smell of gasoline engulfs the interior of the vehicle. This is putting mine and the life of my family at risk, due to a faulty manufacturer issue. Mecedes Benz needs to obviously correct the faulty parts they use as soon as possible, before someone loses their life.
Engine light - crankcase vent valve issue
The Positive Crankcase Ventillation harness fails and check engine light goes on. Through my research I found that many C class and GLC class with same engine have had similar issues and there was a recall and covered. My particular VIN was not included in the recall but had this check engine warning sign before 50K miles warranty expires. The light always went away but now it has come back on for the third time and not going away. The cost to replace this simple module is mostly labor at 8 hours is around $2,000. I believe this is an emission component and need to be covered under state and federal emission standards warranty. The initial recall with this issue should be involved with same engine and cover all cars and SUV's with same engine. I do believe this is an Emission control device that is regulated by state and federal standards and should be covered under warranty.
Premature failure of the PCV assembly at 70,000 miles. Caused vehicle to turn off and sometimes engine to shake.
Positive crankcase ventilation system failure. P052e(77)
Odometer reading more miles then driven (may have been tampered with altered) There is an electrical issue The computer required to be reprogrammed has not been done yet While driving the vehicle completely stop accelerating in the middle of traffic on the interstate placed my life in danger especially because traffic was moving rapidly the vehicle was jerking horribly also several codes came on when the service light came on also needed a pcp vale hose system they never repaired it i asked to have it repaired they agreed and then stated the vehicle had to many issues was sending to auction but yet reselling the vehicle still have not repaired completely this could be dangerous
There are lots of 2017 GLC 300 that has been having issues with PCV system that are malfunctioning that could cause engine failure. Customers are forced to spend $2000 plus to have this fixed rather than Mercedes owning its problem and fixing it. For your reference please check glcforum.com where glc owners are ranting their issues with PCV systems. https://www.glcforums.com/threads/2019-glc300-4matic-pcv-code-crankcase-ventilation-oil-separator.7997/
Intake and exhaust cam shaft and adjuster failure at 83,000 miles. Failure caused vehicle not to accelerate and stalled starts. Was on the highway when vehicle wouldn’t accelerate putting driver and others on road in danger. Repair on vehicle costing over $5k and MBUSA has no recourse due to vehicle being out of warranty. Per techs this issue should not happen to the engine.
With a low milage car receiving a P052E positive crankcase ventilation regulator valve performance issue.
My car has P052E code with a message of Positive Crankcase Ventilation Regulator Valve Performance. My car mileage is only 13,700 as of today. I think this is a cause of a deflective part and this should be a recall item. FYI, Wen I contact a Mercedes dealership and they asked me a cost of $2,500 to fix this issue. Thank you,
The contact owns a 2017 Mercedes-Benz GLC300. The contact stated that while driving approximately 55 MPH, she detected white smoke coming from the tailpipes. There were no warning lights illuminated. The contact was able to pull over. The vehicle was towed to the local dealer who placed a camera inside the engine and noticed that the piston had fractured and detached inside the engine. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was contacted but no additional assistance was provided. The approximate failure mileage was 88,000.
engine light caused by Crankcase pressure sensor
Catastrophic engine failure at 63,000 miles. Mechanic says its a known issue with this particular make and model of that year. Dealer says I need to replace the engine.
Getting error code P052e which has been a very common issue with these engines on Mercedes models. It does not affect driving but since it’s out of warranty, it will cost over $3,000 to repair. Mercedes knows this and included it on their extended warranty for Diesel engines, not gasoline.
I was suggest by dealer to replace crank case vent value as its blocked and quoted $300 for part and 1800 for labor cost as they need to remove whole engine and replace part. Issue is how can mercedes benz design such engine with 6-7 hrs of labor intensive work and 6 times higher labor cost than part cost. I was told this work is necessary for engine efficiency and to pass SMOG test. I feel design issue is related to car / passenger safety and environment hazard. Also it looks like a very common recurring issue with mercedes models based google search. Added to it local dealer didnt find a problem when my car is under warranty or within service packages. Warranty completed and came up with these problems.
Was driving on the freeway car started to shake. Speed dropped from 73 to 40 I was thankfully able to merge off the freeway. I stoped to see if there was any visible damage. Everything look normal. Was able to make it home. Husband changed spark plugs and coils. Also bought another small part nothing fixed it. Took it to two different auto shops one being Mercedes. They both confirmed it's a blown engine at 47,000 miles. Unbelievable.
driving car and engine failed, #1 piston crack, turbo metal filings ruined it also, very expensive repair. both engine and turbo had to be replaced by mercedes benz service. many others are reporting this also, catastrophic failure at speed possible - not known if any fatalities associates with these engines (on both c300 and glc300 circa 2015 to ~2018)
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Categories with enough reports to have a page of their own
Data on this page last refreshed .