Mercedes-Benz · Known Issues
2025 Mercedes-Benz GLS Problems: 6 Known Issues
2025 model year · 950+ owner reports · Updated September 2026
2025 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
2025 model year · 950+ owner reports · Updated September 2026
2025 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
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According to Au7o's analysis of 950+ owner reports, the 2025 Mercedes-Benz GLS has 6 documented known issues, with 1 rated critical. The most serious is 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk ($2,500-$7,000 repair). The most commonly reported issue is Panoramic Sunroof Water Leak with 500 owner reports. Across all issues with published estimates, repair costs range from $100 to $8,000. DIY maintenance guides at au7o.io.
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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.
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.
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.
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.
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.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
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.
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.
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.
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.