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NHTSA-Verified · Common Problems

2018 Mercedes Benz C Class Phev
Common Problems

Ranked from 49 federal NHTSA complaints. Every problem links to the complaint IDs behind it.

3
High severity
9
Medium
1
Low

13 Common Problems

Ordered by how often owners reported each one to NHTSA. The bar shows how common a problem is relative to the most-reported on this vehicle. Expand any problem to see the federal complaint IDs.

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  1. 1

    Positive Crankcase Ventilation (PCV) Valve Failure

    16complaints
    High severityEngine

    The PCV valve repeatedly fails, leading to engine light activation and requiring expensive repairs.

  2. 2

    Recall Issues with Steering and Air Bags

    9complaints
    High severityOther

    Issues with recall repairs for steering and air bags, leading to delays and unresolved problems.

  3. 3

    Check Engine Light Activation Due to Sensor Malfunction

    8complaints
    Medium severityEngine

    The check engine light frequently activates due to malfunctioning sensors, often related to the PCV valve.

    $100–$250est. professional diagnosis · 1–2 hrs labor
    Get local quotes
  4. 4

    Panoramic Sunroof Malfunction

    8complaints
    Medium severityOther

    The panoramic sunroof fails to close properly or detaches unexpectedly, leading to potential water intrusion and safety concerns.

  5. 5

    Check Engine Light Due to Positive Crankcase Ventilation Issues

    7complaints
    Medium severityEngine

    The check engine light illuminates due to a malfunction in the positive crankcase ventilation system, often requiring expensive repairs.

    $100–$250est. professional diagnosis · 1–2 hrs labor
    Get local quotes
  6. 6

    Engine Stall at Idle Due to Stop-Start System Failure

    7complaints
    Medium severityEngine

    The engine frequently stalls at idle, especially when the car is stopped for extended periods.

    $150–$900est. stop-start system diagnosis · 1–4 hrs labor
    Get local quotes
  7. 7

    Tire Blowouts and Shredding

    5complaints
    Medium severityOther

    Multiple instances of tire blowouts and shredding, affecting safety and reliability.

  8. 8

    Sunroof Not Opening Properly

    4complaints
    Medium severityOther

    The sunroof fails to open or close properly, leading to potential water intrusion and inconvenience.

  9. 9

    Air Bag Recall Issues

    3complaints
    Medium severityElectrical

    Problems with TAKATA air bag recall repairs, including delayed availability of parts.

  10. 10

    Front Roof Panel Detachment

    3complaints
    High severityOther

    The front roof panel detaches unexpectedly, posing a safety risk as it can lead to water intrusion and structural failure.

  11. 11

    Seat Belt Retraction Failure

    3complaints
    Medium severityOther

    The seat belts fail to retract properly, posing a safety risk during sudden stops or collisions.

  12. 12

    Headlight Issues

    2complaints
    Low severityOther

    Headlights fail to work properly, affecting visibility during nighttime driving.

    $100–$900est. lighting assembly repair · 0.5–2 hrs labor
    Get local quotes
  13. 13

    Steering Rack Locknut Material Cracks

    2complaints
    Medium severitySteering

    Potential internal material cracks in the steering rack locknut, requiring ongoing recall checks.

    $900–$2,000est. steering rack replacement · 4–8 hrs labor
    Get local quotes

Other years & sources

2016 Mercedes Benz C Class PhevAll NHTSA complaints for this vehicle →

Data source: U.S. National Highway Traffic Safety Administration (NHTSA) owner complaints and recalls. Problems are clustered and ranked from the complaint record; occurrence counts reflect corroborating complaints, not total incidence. Vehicle image is illustrative. Repair-cost figures are typical U.S. independent-shop ranges (parts + labor) for the class of repair shown — actual quotes vary by region, engine, and diagnosis; always confirm with a local shop.