Mercedes-Benz GLC300 Engine Problems
Owners have filed 200 complaints with NHTSA about engine problems on the Mercedes-Benz GLC300 across 10 model years. The 2016 model year has the most (38). The words owners use most often: “crankcase ventilation” (14% of reports).
- 200engine complaints
- —median miles at failure
- 4mention a crash
- 1mention an injury
- 3related recalls
- $7,400typical repair cost reported by owners
- 38%of reports with a speed happened at 50+ mph
What owners describe
Phrases that appear unusually often in these complaints compared with complaints about other cars.
- Crankcase ventilation: mentioned in 27 of 200 complaints (14%)
- Cylinder head: mentioned in 23 of 200 complaints (12%)
- Code P052E: mentioned in 14 of 200 complaints (7%)
- Regulator valve: mentioned in 13 of 200 complaints (7%)
How much does it cost to fix?
Owners who wrote down what they paid or were quoted put the typical engine repair on the Mercedes-Benz GLC300 at $7,400, and half of them between $2,650 and $10,100.
Based on 21 NHTSA complaints about this problem alone that state a repair bill or quote (2022–2026), converted to 2026 dollars with the U.S. consumer price index. These are owners' own figures, not a quote: they include dealer quotes, and owners who file complaints often faced larger repairs, so they can run higher than typical shop prices. Prices vary by shop, region and warranty coverage. How we calculate this.
At what mileage do engine problems happen?
Based on 36 complaints that reported the odometer reading.
How serious are the reports?
Of 200 complaints, 4 mention a crash, 7 a fire, 1 an injury.
Mercedes-Benz GLC300 engine complaints by model year
| Model year | Engine complaints | Share of that year | Median miles |
|---|---|---|---|
| 2025 GLC300 | 3 | 19% | 17,107 |
| 2024 GLC300 | 7 | 33% | — |
| 2023 GLC300 | 15 | 27% | 400 |
| 2022 GLC300 | 10 | 16% | — |
| 2021 GLC300 | 30 | 45% | 7,000 |
| 2020 GLC300 | 21 | 30% | 30,000 |
| 2019 GLC300 | 11 | 23% | — |
| 2018 GLC300 | 28 | 32% | 6,000 |
| 2017 GLC300 | 37 | 37% | 60,000 |
| 2016 GLC300 | 38 | 29% | 12,000 |
When owners reported it
Related recalls (3)
Engine and engine cooling:critical fasteners; fuel system, gasoline:delivery:fuel pump
Model years: 2023
Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2023 GLC300, 2024 GLE350, and GLE450 vehicles equipped with an M254 engine. The incorrect screws, installed on the high-pressure fuel pump, may prevent a proper seal from forming between the high-pressure fuel pump and the tandem oil pump.
Risk: An inadequate seal can allow fuel and oil to leak onto the road, creating a hazard for other road users and increasing the risk of a crash. Additionally, a fuel and oil leak in the presence of hot engine components can increase the risk of a fire.
Fix: Dealers will replace the high-pressure fuel pump, free of charge. Owner notification letters were mailed February 9, 2024. Owners may contact MBUSA customer service at 1-800-367-6372.
Engine and engine cooling:engine:gasoline:turbo/supercharger
Model years: 2020
Problem: Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2020 C300, E350, and GLC300 vehicles equipped with turbocharged 4-cylinder gasoline engines. The screws that retain the turbocharger oil feed and return lines may not have been properly tightened, possibly resulting in an oil leak.
Risk: An oil leak in the presence of an ignition source such as hot engine or exhaust components can increase the risk of a fire.
Fix: MBUSA will notify owners, and dealers will inspect the turbocharger oil lines and tighten them as necessary, free of charge. The recall began August 17, 2020. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2020070017.
Electrical system:starter assembly; engine and engine cooling:engine
Model years: 2016, 2017
Problem: Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2015-2017 C300 4Matic, C300, CLA250, CLA250 4Matic and CLA45 AMG vehicles, 2017 C300 4Matic Cabrio, C300 4Matic Coupe, C300 Cabrio, C300 Coupe, E300, E300 4Matic, E400 4Matic Wagon, E43 AMG 4Matic, GLA250, GLA250 4Matic and GLC300 4Matic Coupe vehicles and 2016 C350e and GLC300 vehicles and 2016-2017 C450 4Matic AMG Sport and GLC300 4Matic vehicles. In the event that the engine or transmission cannot turn over, the starting current limiter may overheat from the repeated attempts of the starter motor attempting to start the vehicle.
Risk: If the starting current limiter overheats, the surrounding components can melt, increasing the risk of a fire.
Fix: MBUSA will notify owners, and dealers will install an additional fuse in the electrical line to the starter, free of charge. The recall began August 31, 2017. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2017080002.
What owners report
Short excerpts of recent complaints, with personal details removed. Full reports are on NHTSA.gov.
My check-engine light recently illuminated, and diagnostic testing identified fault code P06DA00, relating to the oil pump control valve circuit. I have been quoted over $5,000 to replace the oil control valve and oil pump harness. I was quoted the following by Mercedes Servuce in Manchester, NH…
The vehicle is experiencing an intermittent, sudden, and life-threatening drop into "limp home mode" while driving, creating an severe speed differential with surrounding traffic.First Incident (50,584 miles): The vehicle entered limp mode. Authorized Mercedes service center scanned the car…
My 2022 Mercedes-Benz GLC 300 (17,700 total miles) suffered a catastrophic structural engine block failure and an explosive loss of propulsion while driving at highway speeds. This occurred exactly 6 days and 183 miles after a franchised Mercedes-Benz dealership performed the official fuel pump…
Error code P052E71 on a 2018 Mercedes-Benz GLC 300 4MATIC means the Positive Crankcase Ventilation (PCV) Regulator Valve Performance has a malfunction, specifically that the partial-load ventilation valve actuator is blocked. By research, i found that this is a very common problem on those engines…
While driving down a busy neighborhood street 2 lanes with cars on both sides making it a 1 lane road pulled over to the side a little to let cars pass. All of a sudden ALL electrical and engine stopped and turned off. Only thing that was powered was instrument cluster with multiple warnings like…
Frequently asked questions
Do all Mercedes-Benz GLC300s have engine problems?
No. NHTSA has 200 owner complaints about engine for the Mercedes-Benz GLC300. Complaint data shows that the problem is reported, not how many of all cars sold are affected.
Was there a recall on the Mercedes-Benz GLC300 engine?
Yes: 3 safety recalls list engine. Check your VIN on NHTSA.gov to see whether the fix was done on your car.
How much does it cost to fix engine problems on the Mercedes-Benz GLC300?
Owners report a typical cost of $7,400 (half paid between $2,650 and $10,100), from 21 complaints that state a repair bill or quote, in 2026 dollars.
What do owners say about engine problems on the Mercedes-Benz GLC300?
The most frequent phrase is “crankcase ventilation”, in 27 of 200 complaints, followed by “cylinder head” (23).
Other Mercedes-Benz GLC300 problems
See all Mercedes-Benz GLC300 problems.