2018 Mercedes-Benz GLC 300 used buying checklist

Test for the problems owners report most

The most reported problems of this model year, with what to look for on the test drive.

• Check engine light16 owner complaints

  Start the engine cold and listen for knocking or ticking. Check for warning lights, oil leaks and a low oil level, and ask how often oil had to be topped up.

• Seat belt won't latch or retract6 owner complaints

  Pull every seat belt out fully and make sure it retracts and latches.

• Airbag warning light5 owner complaints

  Make sure the airbag warning light turns off after start-up, and that every airbag recall was completed.

Make sure these recalls were done

Recall repairs are free at any dealer of the brand. Ask the seller for proof, or have a dealer check the VIN.

• StructureRecall number 23V854000, Dec 15, 2023
• Electrical systemRecall number 22V365000, May 20, 2022
• StructureRecall number 21V197000, Mar 19, 2021
• CommunicationRecall number 21V072000, Feb 12, 2021
• Electrical systemRecall number 21V058000, Feb 5, 2021
• Air bagsRecall number 18V838000, Nov 27, 2018
• Seat beltsRecall number 18V683000, Oct 1, 2018
• Exterior lightingRecall number 18V610000, Sep 11, 2018
• Air bagsRecall number 18V208000, Mar 29, 2018
• Seat beltsRecall number 18V177000, Mar 15, 2018
• VisibilityRecall number 17V715000, Nov 14, 2017
• Air bagsRecall number 17V627000, Oct 6, 2017

Repairs the maker may still cover

Warranty extensions can cover a known problem beyond the normal warranty. Check whether this car is still within the time or mileage limit.

• Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz...Aug 15, 2026
• Fuel/propulsion systemJul 31, 2026
• In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the...May 15, 2025
• EngineJul 9, 2024
• Mercedes-Benz AG (“MBAG”), the manufacturer of Mercedes-Benz vehicles, has extended the warranty for the...Aug 5, 2022
• Fuel/propulsion systemAug 20, 2021
• Visibility/wiperOct 29, 2020
• EngineMar 13, 2019

Service bulletins worth asking about

Repair instructions the maker sent to dealers for known problems. Ask whether any of these repairs were done.

• Clanking noise from the area of the speakers in the doorsSep 14, 2026
• Tailgate opens unintentionallyAug 24, 2026
• 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active...Aug 12, 2026
• A popup is seen on the HU with the message "data connection temporarily not available". Potentially...Aug 6, 2026
• Service code B1 displayed in the customer menu does not match the workshop code displayed in the workshop...Jun 12, 2026
• The customer requests deactivation of the N112/9 HERMES communication module Note: Deactivation of the...May 26, 2026

Before you pay

• Decode the VIN and make sure it matches the title, the registration and the car itself.
• Get a vehicle history report to check for accidents, salvage or flood titles and odometer problems.
• Ask for service records, especially oil changes and any transmission fluid service.
• Start the car from cold, and drive it at city and highway speeds for at least 20 minutes.
• Have an independent mechanic inspect the car before you sign anything.