What are the most common Mercedes-Benz GLS problems?
According to Au7o's analysis of 950+ owner reports, the 2025 Mercedes-Benz GLS has 6 documented issues. The most frequently reported are: 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk, Panoramic Sunroof Water Leak, Battery Drain from 48V System. Of these, 1 is rated critical and should be addressed promptly.
Is the Mercedes-Benz GLS reliable?
The 2025 Mercedes-Benz GLS has 6 known issues documented across 950+ owner reports. 1 issue is rated critical: 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Mercedes-Benz GLS problems?
Repair costs for known Mercedes-Benz GLS issues range from $0 to $8,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk, typically costs $2,500-$7,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2020-2025 Mercedes-Benz GLS 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk?
The 4MATIC transfer case on the GLS is prone to internal bearing wear, typically beginning with fluid degradation or a slow leak from the output/case seals. As the bearings wear, owners report a whining or grinding noise that increases with vehicle speed and worsens over time. On… Repairs typically run $2,500-$7,000. Severity: high.
What is the 2020-2025 Mercedes-Benz GLS Panoramic Sunroof Water Leak?
The large panoramic sunroof on the X167 GLS develops water leaks at the drain tubes or seal interface. Water enters the headliner and can drip into the cabin, staining the headliner and potentially damaging the overhead electronics. Repairs typically run $100-$1,500. Severity: medium.
What is the 2020-2025 Mercedes-Benz GLS Battery Drain from 48V System?
The 48V EQ Boost mild hybrid system causes excessive battery drain when parked. A software bug in the 48V battery management module fails to properly enter sleep mode, draining both the 48V lithium-ion and 12V lead-acid batteries. Repairs typically run $200-$3,500. Severity: medium.
What is the 2020-2025 Mercedes-Benz GLS OM656 Diesel Emissions System Clogging (EGR/DPF/AdBlue SCR) and Limp Mode?
EU-market GLS 350d/400d models with the OM656 3.0L inline-six diesel suffer from sensitivity in the exhaust aftertreatment chain. The EGR (AGR) valve, diesel particulate filter (DPF) and SCR/AdBlue system are sensitive to poor fuel quality, short-trip driving and temperature swin… Repairs typically run $300-$2,500. Severity: medium.
What is the 2020-2025 Mercedes-Benz GLS OM656 Diesel CP4 High-Pressure Fuel Pump Sensitivity and Injector Damage?
The OM656 diesel uses a precise Bosch CP4 common-rail high-pressure fuel pump that reacts poorly to low-quality diesel or fuel contamination. Even minor tank impurities or a single mis-fueling event can damage the pump and injection nozzles, and metallic debris from a failing CP4… Repairs typically run $1,500-$8,000. Severity: medium.
What is the 2020-2025 Mercedes-Benz GLS MBUX Infotainment Freezing, Black Screen and Random Reboots?
GLS X167 owners report the MBUX infotainment system freezing, showing a black or flickering screen, distorted display, unresponsive touch controls, or randomly rebooting. The faults are intermittent and often software-related, frequently triggered by or persisting through OTA/sof… Repairs typically run $0-$600. Severity: low.
