2021 Mercedes-Benz Glc
Vehicle Specs & Maintenance Data
The 2021 Mercedes-Benz Glc maintenance specs on this page cover the key fluids, torque values, and wear items you need for routine service. Use these numbers as a quick reference when performing oil changes, tire rotations, brake jobs, and other scheduled maintenance on your Mercedes-Benz Glc.
For oil changes, the 2021 Mercedes-Benz Glc takes 0W-40 Full Synthetic motor oil with a capacity of 5.5 quarts. Brake fluid type is DOT 4, the recommended coolant is MB 325.0 (Blue, silicate-free), and transmission fluid is MB 236.14. Always use the manufacturer-recommended fluids to maintain warranty coverage and engine longevity.
When mounting wheels on the Mercedes-Benz Glc, torque the lug nuts to 96 ft-lbs using a calibrated torque wrench. Over- or under-torquing can lead to warped brake rotors or loose wheels. Re-torque after 50 to 100 miles on newly installed wheels.
Owners of the 2021 Mercedes-Benz Glc have reported 5 common issues including "Rear Subframe Mounting Point Cracks", "48V Mild Hybrid EQ Boost Starter-Generator Failure" and "MBUX Infotainment System Freezing and Rebooting". Scroll down to the Diagnostics tab for detailed descriptions, solutions, and estimated repair costs.
Specifications on this page are compiled from multiple publicly available sources including manufacturer documentation, NHTSA data, and automotive databases. Always cross-reference with your owner's manual or official factory documentation before purchasing parts or performing any service.
The 2021 Mercedes-Benz Glc uses 0W-40 Full Synthetic motor oil (5.5 qt capacity), requires lug nuts torqued to 96 ft-lbs, takes DOT 4 brake fluid.
Manufacturer-recommended maintenance schedule for the 2021 Mercedes-Benz Glc. Always verify intervals against your owner's manual.
Enter a diagnostic trouble code to see causes, symptoms, and fixes for the 2021 Mercedes-Benz Glc.
Common problems reported by 2021 Mercedes-Benz Glc owners, with recommended fixes and estimated repair costs.
Rear Subframe Mounting Point Cracks
Owners report cracking at the rear subframe mounting points, particularly on GLC 300 models driven on rough roads. Symptoms include clunking noises from the rear suspension, uneven tire wear, and handling instability. The issue has been documented in NHTSA complaints and affects the structural integrity of the rear suspension attachment.
Dealer inspects and reinforces or replaces the rear subframe mounting brackets. Mercedes-Benz issued TSB LI05.40-P-071099 addressing rear suspension noises. Subframe replacement is required if cracking is severe.
Est. Cost: $1,200 - $4,50048V Mild Hybrid EQ Boost Starter-Generator Failure
The 48-volt EQ Boost integrated starter-generator (ISG) system can malfunction, causing rough engine starts, inability to restart after auto stop-start, and loss of the mild hybrid assist function. Warning messages such as 'Electric System: Workshop' or 'Start/Stop not available' appear on the instrument cluster.
Dealer replaces the ISG unit and updates the control module software. The 48V battery may also need replacement if degraded. Reference Mercedes-Benz TSB LI27.19-P-065930 for ISG diagnostic procedures. Covered under powertrain warranty.
Est. Cost: $0 (warranty) - $3,500 (out of warranty)MBUX Infotainment System Freezing and Rebooting
The second-generation MBUX infotainment system experiences frequent freezing, spontaneous reboots, and black screen events. Navigation may stop working mid-route, Apple CarPlay and Android Auto connections drop intermittently, and the touchscreen becomes unresponsive. Approximately 15-20% of NHTSA complaints for the 2022 GLC involve infotainment issues.
Dealer performs an MBUX software update to the latest firmware version. In persistent cases, the head unit (NTG 7) must be replaced. Reference Mercedes-Benz Service Campaign 2022100003 for display software updates.
Est. Cost: $0 (software update) - $2,500 (head unit replacement)Panoramic Sunroof Stress Cracks and Rattle
The panoramic sunroof glass can develop spontaneous stress cracks without external impact, particularly in extreme temperature changes. Even without cracking, owners report persistent rattling and wind noise from the panoramic sunroof assembly at highway speeds. Several NHTSA complaints document the glass shattering while the vehicle was parked.
Dealer replaces the panoramic sunroof glass assembly. Rattling is addressed by adjusting the sunroof rail guides and applying additional weatherstripping. Some repairs may be covered under the comprehensive warranty or goodwill if the crack appears spontaneous.
Est. Cost: $800 - $2,200Engine Oil Leak from Oil Filter Housing Gasket
The 2.0L M264 turbocharged engine develops oil leaks at the oil filter housing gasket, a common failure point on many Mercedes-Benz four-cylinder engines. Owners notice an oil burning smell, visible oil drips on the driveway, and low oil warnings. The leak can drip onto hot exhaust components, creating a potential fire hazard.
Dealer replaces the oil filter housing gasket and inspects for oil contamination on adjacent components. The repair requires removal of the intake manifold for proper access. Reference TSB LI18.00-P-058843 for oil leak diagnosis on M264 engines.
Est. Cost: $600 - $1,200