The vehicle was brought to an authorized Hyundai dealer to have Service Campaign TBH and 94B completed. These campaigns were explicitly designed to prevent known mechanical defects (cracked EHRS assemblies and high-voltage battery errors). The software patches failed to protect the vehicle. The physical hardware has now catastrophically failed exactly as predicted by the campaign, resulting in extreme engine overheating and a physically swollen high-voltage battery pack. Hyundai is refusing to cover the cascading physical damage caused by their own failed campaign remedy, leaving me with an active safety and fire hazard. FUEL/PROPULSION SYSTEM" and explicitly state that the vehicle experienced an unchecked thermal event due to an ineffective corporate software update (Campaign TBH / 94B). All documents I have supporting this will not fit in this upload limit.
Hyundai Sonata Hybrid overheating problems
33 of the 798 owner complaints about the Hyundai Sonata Hybrid describe engine overheating, most of them for the 2021 model year.
- owner complaints
- 33
- worst model year
- 2021
- typical repair cost reported
- $15,000
- typical mileage
- 82,000
By model year
Often reported together
Fire or smoke 9Engine failure 6Won't start 3Loss of power 3Check engine light 3Stalling 2Knocking 2
What owners say
The contact owns a 2013 Hyundai Sonata. The contact stated that while driving 40 MPH, the malfunction indicator and coolant temperature warning lights illuminated, and the engine overheated and shuddered abnormally. There was smoke and an abnormal ticking sound coming from underneath the hood of the vehicle. The contact was able to pull into a parking lot, and the vehicle was turned off. The contact became aware that the VIN was included in the federal safety agency Campaign Number: 23V651000 (Service Brakes, Hydraulic). The vehicle was not diagnosed or repaired by a dealer or an independent mechanic. The manufacturer was not notified of the failure. The failure mileage was approximately 147,000.
The contact owns a 2011 Hyundai Sonata. The contact stated that while driving on the highway at 60 MPH, there was smoke coming from the rear of the vehicle. The contact immediately pulled over to inspect the vehicle. Upon checking under the hood, the contact noticed that the coolant level was low. The contact attempted to restart the vehicle; however, the vehicle failed to start. The vehicle was towed to a dealer, where it was diagnosed, and the contact was advised that the engine had overheated and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 130,000.
Overheated engine alarm came on while I was on the freeway on a rainy day. Vehicle was towed to Hyundai dealership in which service technician found that the part preventing water from leaking into the muffler was broken. Hyundai dealership has ordered replacement part but it is on backorder. The broken part that needed replacement has been on backorder for close to a month and there is not an ETA of when the part will be received. Prior to the overheated engine alarm going off, cold air was blowing out of the vents even when the heat option was selected.
Coolant system leaks in to the engine or exhaust system, which is evident in white smoke exhaust and coolant level dropping. In my situation, I required an entire container of coolant to perform a daily commute, and the reservoir was empty by the time I made it to the dealership. Car is rendered undrivable due lack of coolant and engine overheating. My car was in the dealership repair facility for 6 weeks awaiting parts on back order due to nationwide shortage. A technical service bulletin has been issued for this manufacturer defect (23-EM-009H). Cost of repairs was roughly $2,300.
EHRS Coolant Leak- problem started in [XXX] when engine overheated. The weather in Michigan in inclement and being stranded in the intense cold can lead to loss of life. I had it towed to a Hyundai dealership that was unable to find the problem and in attempting to "find a leak" used the incorrect dye, necessitation transferal to another more competent dealership where the problem was diagnosed and was fixed with a replacement part. In December 2023 a TSB 23-EM-009h was issued by Hyundai describing this problem and issuing a part (Center Muffler). I was not informed and the problem recurred. currently this is the third episode and Hyundai after paying 95% of the previous cost, now only agrees to pay 85% and denies reimbursing me for the car rental. Warning lights appeared with all 3 occurrences. Hyundai should have issued a recall to obviate this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
My engine coolant level keeps going down but no leaks evident also heavy white smoke coming out from the exhaust. Finally engine overheated.
Coolant leak acting like blown head gasket. Coolant was leaking into the exhaust system. Defective EHRS system
EGR cooler leaks and slowly burns off engine coolant resulting in the car overheating while driving, forcing a quick exit from the road, or stopping in traffic not to damage the engine. Google search shows this is a very common issue with these hybrids.
The contact owns a 2015 Hyundai Sonata Hybrid. The contact stated while driving 45 MPH, the vehicle started overheating, and smelled an abnormal electrical burning odor inside the cabin. Several unknown warning lights were illuminated. The contact veered to the side of the road, turned off the vehicle and inspected under the hood. The contact stated that the vehicle failed to restart and was towed to the residence. The contact received notification of the federal safety agency Campaign Number: 23V651000 (Service Brakes, Hydraulic) which he related to the failure. The dealer was notified of the failure. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.
Related recalls
Engine
- What is wrong
- Hyundai Motor America (Hyundai) is recalling certain 2017 Tucson and Sonata Hybrid vehicles. The connecting rod bearings inside the engine may wear prematurely, which can result in engine damage.
- Risk
- A damaged engine can increase the risk of a fire or it can cause an engine stall, increasing the risk of a crash.
- Remedy
- Dealers will inspect the engine. If bearing damage is found, the engine will be replaced. Dealers will also install a software update containing a new Knock Sensor Detection System (KSDS). Repairs will be performed free of charge. Owners were notified of the defect on November 16, 2021. Owner notification letters were mailed January 15, 2022. Owners may contact Hyundai customer service at 1‑855‑371‑9460. Hyundai's number for this recall is 209.
Recall number 21V727000 · Recall details
Engine
- What is wrong
- Hyundai Motor America (Hyundai) is recalling certain 2015-2016 Veloster, 2012 Santa Fe, 2011-2013 Sonata Hybrid, and 2016 Sonata Hybrid vehicles. The connecting rod bearings inside the engine may wear prematurely, which over time can result in engine damage.
- Risk
- A damaged engine can increase the risk of a fire or it can cause an engine stall, increasing the risk of a crash.
- Remedy
- Hyundai will notify owners, and dealers will inspect the engine. If bearing damage is found, the engine will be replaced. Dealers will also install a software update containing a new Knock Sensor Detection System (KSDS). Repairs will be performed free of charge. The recall began March 31, 2021. Owners may contact Hyundai customer service at 1‑855‑371‑9460. Hyundai's number for this recall is 198.
Recall number 20V746000 · Recall details
Questions about the Hyundai Sonata Hybrid overheating
Which Hyundai Sonata Hybrid years have engine overheating problems?
The model years with the most reports are 2021 (11 complaints), 2011 (7 complaints) and 2020 (6 complaints).
How much does it cost to fix engine overheating on the Hyundai Sonata Hybrid?
Owners who mentioned a price put the repair at about $15,000 (median of 6 complaints that include a dollar amount). Costs vary with mileage, warranty and where the work is done.
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