2017 Mercedes-Benz C300 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 light37 owner complaints, owners paid about $2,000

  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.

• Gas smell in the cabin18 owner complaints

  Watch for fuel smells, hard starting and the check engine light, and make sure the fuel gauge works.

• Seat belt won't latch or retract14 owner complaints, usually around 20,000 miles

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

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
• Seat beltsRecall number 21V032000, Jan 29, 2021
• CommunicationRecall number 19V787000, Nov 1, 2019
• SeatsRecall number 19V130000, Feb 26, 2019
• SteeringRecall number 18V850000, Nov 29, 2018
• StructureRecall number 18V456000, Jul 10, 2018
• SeatsRecall number 18V207000, Mar 29, 2018
• Air bagsRecall number 17V627000, Oct 6, 2017
• SteeringRecall number 17V243000, Apr 11, 2017
• Seat beltsRecall number 17V251000, Apr 11, 2017
• Electrical systemRecall number 17V114000, Feb 23, 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.

• EngineJul 9, 2024
• 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.