2021 Hyundai Sonata Complaints

  • Engine 08/10/2024

    The Exhaust Heat Recovery System (EHRS) has failed for the second time on this vehicle. The first failure occurred at approximately 35,000 miles and was repaired under Hyundai Technical Service Bulletin 23-EM-009H, which Hyundai issued to address this exact defect across 2020-2023 Sonata Hybrid models. The vehicle has now reached 71,000 miles and is experiencing the identical symptoms: coolant loss, overheating, and white exhaust smoke. The EHRS shares a coolant loop with the hybrid battery thermal management system. Coolant loss from this failure puts the hybrid battery and power electronics at risk of overheating, creating a potential fire and safety hazard. The recurring nature of this failure following an official TSB repair suggests the root cause has not been adequately addressed by Hyundai's current repair protocol.

  • Structure, unknown Or Other 01/30/2026

    • I experienced trouble with my splash guard being damaged from hanging and scraping the ground about a month after purchasing the vehicle. Also, my hood paint started chipping after a recent cold front experienced in my state earlier this year. Yes it is available for inspection upon request. Regarding the splash guard, not applicable. • It’s was very inconvenient to drive with a portion of my car scraping the ground. I had to be more mindful of my driving in the higher speed limit areas incase the splash guard detached. I had it re-attached multiple times. Regarding the chipped paint, not applicable. • It it counts, for my splash guard, during a servicing, I asked Hyundai to re-attach it. For the chipped paint, no. • The splash guard has during a past servicing. The chipped paint is more recent so it hasn’t • No. Splash guard, a month after purchasing vehicle. The chipped paint, earlier this year, January-February 2026.

  • Unknown Or Other, fuel/propulsion System 03/13/2026

    I was notified of a recall on my from vehicle by Hyundai via email some time in March of 2026. The message said mentioned my vehicle may have a defective/worn purge control check valve that would cause the fuel tank to deform. Potentially leading to a release of fuel over time, which then could ignite. NHTSA Recall #25V796000 My car showed now signs of problems, but I brought it into a Hyundai dealership on March 13th where they confirmed my vehicle had the issue. They said the situation required I not drive my vehicle and gave me a rental in the meantime. I assumed it would be a simple swap of the fuel tank and everything would be fine. I was offered a buyback from my Hyundai claims manager over the situation, but I figured since its a simple fix, I'd keep my car and have it fixed. Two weeks went by with no update from the dealership, so I walked in for answers. Turns out, the subframe of my car has been damaged by the expanding fuel tank and they are still waiting for updates from...

  • Engine, fuel/propulsion System, visibility/wiper 02/19/2026

    The internal core of the Exhaust Heat Recovery System (EHRS), part of the center muffler/front pipe assembly (#28600-L5210), suffered a catastrophic failure. This allowed approximately 9 gallons of engine coolant to leak directly into the hot exhaust stream. Safety Risk: This failure creates a severe visibility hazard. During acceleration from stop lights and stop signs, the vehicle emits massive, thick clouds of white glycol smoke. The smoke is so dense that it completely obscures the driver's view of trailing vehicles and prevents following drivers from seeing the roadway or my vehicle's brake lights, creating a high risk of rear-end collisions. Additionally, the rapid loss of coolant caused the engine to overheat and lose power while in motion, nearly causing a stall in active traffic. Confirmation: The failure was confirmed by the service department at Washington Hyundai (Invoice #174281). This is the second failure of this specific component (previously failed in Jan 2025). The ma...

  • Fuel System, Gasoline 03/19/2026

    The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); and the vehicle was taken to the dealer for the recall repair; however, the dealer informed the contact that the vehicle was unrepairable, and there was no further information provided. The manufacturer was made aware of the issue, and a case was filed. The manufacturer informed the contact that the field engineers had reviewed the vehicle and advised that a buyback was the best option. Additionally, the manufacturer offered an 8 percent discount on the purchase of a new vehicle. The contact declined the offer because the vehicle had not experienced a failure, and the vehicle would be paid off after two additional payments.

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