2018 Mercedes-Benz GLC Reliability Score & Common Problems

Owners of the 2018 Mercedes-Benz GLC frequently report issues with the transmission shifting unexpectedly into neutral, particularly after driving for 15-20 minutes or when the engine oil temperature exceeds 103-105 degrees Celsius. Symptoms often include the vehicle failing to accelerate, the gear shifter moving to neutral without input, and error codes such as P073E indicating reverse gear engagement issues. Complaints also describe occurrences of the vehicle shutting off at stop lights with a "Transmission Malfunction Stop" message and loud noises or shaking when shifting gears. These issues are reported at various mileages, with one owner mentioning approximately 90,000 miles. Safety implications include a crash due to rolling on an incline and near misses from loss of control in traffic, highlighting potential hazards for used car buyers to consider.

Owners report two primary seat belt issues with the 2018 Mercedes-Benz GLC. Firstly, several complaints describe the rear seat belt latch plates retracting into the interior paneling, rendering the seat belts unusable after rear seats are adjusted. This issue is linked to the rear seats being folded and then returned to their upright position. Secondly, some owners note that the driver's seat belt alarm intermittently activates as if the belt is unbuckled, even when fastened, and requires repeated buckling to silence. These problems are reported at varied mileages, with one case occurring around 48,000 miles. Safety implications include increased injury risk if rear passengers cannot fasten their seat belts.

Owners of the 2018 Mercedes-Benz GLC frequently report issues with the panoramic sunroof and roof components, including panels and glass separating or exploding while driving. Symptoms leading up to these incidents often include excessive wind noise, though some cases occur without prior warning. These problems typically occur while the vehicle is in motion, posing a risk to other road users due to the potential for debris. Additionally, there are reports of the automatic liftgate closing unexpectedly, striking individuals, and a separate incident involving a fire originating in the wheel well after a tire puncture. Complaints span a range of mileages, with some issues appearing as early as 1,110 miles. Potential buyers should be aware of these structural issues and their implications for safety.

Owners of the 2018 Mercedes-Benz GLC frequently report issues with the airbag system, particularly related to airbag warning lights and unexpected airbag deployment. Common symptoms include the illumination of the airbag warning light and, in some cases, a rattling noise from the steering column, which are often linked to faulty clock springs or defective airbag control units. These issues are typically noted around 57,000 to 72,000 miles. Safety implications are evident, with one report of an airbag deploying without cause, resulting in an injury, and another incident involving a crash with a deer where the knee airbag caused significant injury to a shorter driver. Prospective buyers should be aware of these potential issues and consider inspecting these components before purchasing.

Owners of the 2018 Mercedes-Benz GLC frequently report issues with the service brakes, primarily involving persistent squeaking and screeching noises. These symptoms are noted to occur during braking, especially when the vehicle is cold, in reverse, or in specific weather conditions such as cold or snowy days. Complaints often highlight that these noises began shortly after purchase, with some owners experiencing them as early as a few weeks into ownership, and persisting despite multiple service visits and brake pad replacements. While these reports do not mention any direct safety implications such as crashes or loss of control, the recurring nature of the noise and the dissatisfaction with dealer responses are notable. Prospective buyers should be aware of these noise issues, as they appear to be a common and unresolved concern among current owners.

Owners of the 2018 Mercedes-Benz GLC report issues related to the fuel/propulsion system, with some describing the check engine light activating due to code P052E, which relates to the positive crankcase ventilation regulator valve, occurring around 58,000 miles. Another common problem involves the fuel pressure sensor or wiring to the fuel pump control unit, which not only triggers a dashboard warning light but also causes the fuel bay door to malfunction, affecting cars with less than 20,000 miles. Additionally, an owner reports the vehicle unexpectedly shutting off while in ECO mode with auto stop engaged, leading to difficulty restarting the vehicle. No crashes or fires are mentioned, but the sudden loss of engine power while stationary could pose safety concerns. These patterns suggest that potential buyers should be aware of these issues, particularly at higher mileages or when using specific vehicle modes.

Owners of the 2018 Mercedes-Benz GLC frequently report issues with the steering system, primarily involving difficulty turning the steering wheel and a loss of power steering assist. Common symptoms include a malfunctioning steering wheel that becomes hard to turn, loud clanking noises, and warning lights such as the airbag and power steering assist lights illuminating. These issues are often linked to faulty electronic power steering modules, clock springs, and software failures. The problems tend to occur at various mileage points, notably around 8,000 to 70,000 miles. While no crashes or fires are reported, the steering difficulties could potentially affect vehicle control, which is a critical consideration for prospective buyers.