2019 model year · 4,500+ owner reports · Updated April 2026
According to Au7o's analysis of 4,500+ owner reports, the 2019 Mercedes-Benz GLC has 3 documented known issues. No issues are rated critical, indicating generally reliable ownership. The most commonly reported issue is 9G-Tronic Harsh Shifting with 2,000 owner reports. Across all issues, repair costs range from $0 to $2,500. DIY maintenance guides at au7o.io.
On the 2016-2022 Mercedes-Benz GLC, the 9G-Tronic (725.0) nine-speed automatic transmission exhibits harsh downshifts and jerky low-speed behavior, particularly the 1-2 and 2-1 shifts. The transmission software struggles with the many gear ratios at parking lot speeds.
Update the transmission control unit (TCU) software to the latest calibration at a Mercedes dealer. Perform a transmission adaptation reset. If software updates do not help, the valve body may need replacement.
Parts and tips from 2,000+ owners who fixed this issue
On the 2016-2021 Mercedes-Benz GLC, the turbo coolant supply and return lines on the M274 engine develop leaks at the crimp fittings. Coolant drips onto hot exhaust components, creating steam and a sweet smell. If unaddressed, coolant loss leads to overheating.
Replace the turbo coolant lines with updated parts. Mercedes revised the crimp fittings in later production. Top off coolant and bleed the system after repair.
Parts and tips from 1,400+ owners who fixed this issue
On the 2016-2023 Mercedes-Benz GLC, the panoramic sunroof develops creaking and rattling noises over bumps and temperature changes. The glass panel expands and contracts differently than the metal frame, creating friction-induced squeaks especially in cold weather.
Apply silicone-based lubricant to the sunroof seal and guide rails. The dealer can adjust the glass panel alignment and apply felt tape to contact points under warranty. Clean and lubricate the rails twice yearly.
Parts and tips from 1,100+ owners who fixed this issue
Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.
According to Au7o's analysis of 4,500+ owner reports, the 2019-2019 Mercedes-Benz GLC has 3 documented issues. The most frequently reported are: 9G-Tronic Harsh Shifting, M274 Turbo Coolant Line Leak, Panoramic Sunroof Creak and Rattle. None are rated critical, but regular maintenance is recommended.
The 2019-2019 Mercedes-Benz GLC has 3 known issues documented across 4,500+ owner reports. No issues are rated critical, suggesting generally good reliability. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known Mercedes-Benz GLC issues range from $0 to $2,500, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
The 9G-Tronic (725.0) nine-speed automatic transmission exhibits harsh downshifts and jerky low-speed behavior, particularly the 1-2 and 2-1 shifts. The transmission software struggles with the many gear ratios at parking lot speeds. Repairs typically run $150-$2,500. Severity: medium.
The turbo coolant supply and return lines on the M274 engine develop leaks at the crimp fittings. Coolant drips onto hot exhaust components, creating steam and a sweet smell. If unaddressed, coolant loss leads to overheating. Repairs typically run $200-$700. Severity: medium.
The panoramic sunroof develops creaking and rattling noises over bumps and temperature changes. The glass panel expands and contracts differently than the metal frame, creating friction-induced squeaks especially in cold weather. Repairs typically run $0-$500. Severity: low.
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.
