YearToAvoid

2021 Mercedes-Benz Glc300 Problems, Recalls & Reliability

Verdict

Good

Complaint Index

44/100

#6 most-complained of 10 Glc300 years

Based on NHTSA complaints per model-year, not a reliability rating. Methodology

The 2021 Mercedes-Benz Glc300 has a complaint index of 44 and ranks 6th worst out of 10 model years, earning a "Good" rating relative to other years. Engine problems dominate, making up 47% of complaints, with a median failure mileage of 7,000 miles.

Complaints
66
Recalls
9
Crashes / fires
1 / 2
Injuries / deaths
0 / 0
NHTSA overall rating
Not rated
EPA combined MPG
24
22 city / 28 hwy

Top 2021 Mercedes-Benz Glc300 problems

NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.

  1. Engine31 (47%)
  2. Electrical System17 (26%)
  3. Fuel System12 (18%)
  4. Other7 (11%)
  5. Collision Avoidance & Cameras6 (9%)
  6. Transmission & Powertrain4 (6%)
  7. Visibility & Wipers4 (6%)
  8. Structure & Body3 (5%)
  9. Airbags1 (2%)
  10. Lane Departure1 (2%)

What owners report

  • Engine loses power and fails to accelerate when the pedal is pressed, sometimes with the check engine light on, though the engine resumes normal operation after a restart.
  • A broken valve spring caused the engine to stall while driving at very low mileage.
  • Fuel lines have malfunctioned, causing gasoline to leak from under the hood, in one case triggering a fire department response.
  • An incorrectly installed fuel line bracket led to a large gasoline leak underneath a parked vehicle.
  • Windshield wipers judder or skip and fail to clear heavy rain, described as an unfixable known issue by the dealer.
  • The vehicle has braked severely and unexpectedly while approaching intersections or changing into turn lanes with no obstruction present.
2021 Mercedes-Benz Glc300 complaints: complaints filed per month5Mar 2021Nov 2021Dec 2022Jun 2024Feb 2025Jul 2025Dec 2025Aug 2026
86 complaints filed with NHTSA from Mar 2021 to Sep 2026; peak Mar 2025 (5).

2021 Mercedes-Benz Glc300 recalls

9 NHTSA recall campaigns list this model year.

  1. NHTSA 24V070000Feb 2, 2024Electrical System15,502 vehicles

    Exterior lighting:headlights

    Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2019-2022 GLC 300, 2020 GLC 350e, and 2020-2022 AMG GLC 43 vehicles. The headlights may be incorrectly adjusted too high and create a glare for oncoming traffic. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."

    Risk: Incorrectly aimed headlights can reduce the visibility of oncoming traffic, increasing the risk of a crash.

    Remedy: Dealers will inspect the headlight adjustment and correct it if necessary, free of charge. Owner notification letters were mailed February 23, 2024. Owners may contact MBUSA customer service at 1-800-367-6372.

  2. NHTSA 23V445000Jun 26, 2023Fuel System143,551 vehicles

    Fuel system, gasoline:delivery:fuel pump

    Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021-2023 C-Class, E-Class, S-Class, CLS, SL, GT, GLC, GLE, GLS, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle details. The fuel pump may shutdown, which can result in a loss of drive power.

    Risk: A loss of drive power can increase the risk of a crash.

    Remedy: Dealers will replace the fuel pump, free of charge. Owner notification letters were mailed on June 14, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2023070012.

  3. NHTSA 22V365000May 20, 2022Electrical System242,722 vehiclesOver-the-air fix

    Electrical system:software

    Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. An error in the communication module's SIM card software can cause a mobile network connection failure, disabling the emergency call (eCall) system.

    Risk: A disabled eCall system would prevent a vehicle occupant from contacting the emergency services call center in an emergency, potentially delaying emergency responders and increasing the risk of injury.

    Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022. Owner notification letters will be mailed in phases, on July 8, 2022, May 17, 2024, July 29, 2024, and September 27, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers are for this recall is 2022060005 and 2023110006.

See all 9 recalls for the 2021 Mercedes-Benz Glc300 →

2021 Mercedes-Benz Glc300 fuel economy and fuel cost

City
22 MPG
Highway
28 MPG
Combined
24 MPG
Annual fuel cost (EPA)
$3,300
15,000 mi/yr
Fuel
Premium
Current regular gas
$4.32/gal
national avg.

EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.

2021 compared with other Glc300 years

Complaint Index by model year (0 = fewest issues, 100 = most)02550751002016201720182019202020212022202320242025
Complaint Index: 0 = fewest issues, 100 = most, relative to other years of this model. Avoid Caution Good Best
YearVerdictIndexComplaintsRecallsMPG
2019Best0471224
2020Caution56691624
2021Good4466924
2022Avoid7859224
2023Avoid100551226

All Mercedes-Benz Glc300 years: best and worst →

Frequently asked questions

Is the 2021 Mercedes-Benz Glc300 reliable?
Compared to other Glc300 model years, 2021 rates "Good" with a complaint index of 44 and ranks 6th worst out of 10 years tracked. It has fewer complaints (66) than the worst years like 2016 (133) and 2023 (100 index).
What is the biggest problem with the 2021 Glc300?
Engine problems are the top issue, accounting for 47% of complaints (31 of 66), with a median failure mileage of 7,000 miles.
Does the 2021 Glc300 have recalls?
NHTSA lists 9 recalls for the 2021 Glc300, covering the electrical system, fuel system, airbags, and structure/body components, including a fuel pump replacement recall.
Are there fuel system issues on the 2021 Glc300?
Yes. NHTSA lists 12 fuel system complaints, 18% of the total, with a median failure mileage of 9,729.5 miles, plus a recall for fuel pump replacement.
How does 2021 compare to other Glc300 years?
2021's complaint index of 44 is better than 2016 (89), 2020 (56), 2022 (78), and 2023 (100), but worse than 2017 (22), 2018 (33), 2019 (0), and 2024 (11).

Sources: NHTSA Office of Defects Investigation complaint and recall databases; U.S. EPA fuel economy data; NHTSA 5-Star Safety Ratings. Complaints are unverified owner reports.

Data updated Sep 24, 2026. Read the methodology and data sources. The Complaint Index is based on NHTSA owner complaints and recalls; it is not a reliability rating.