2017 Hyundai Sonata: engine overheating

Filed Jun 6, 2026 · Engine, Suspension · PA

[XXX] [XXX] [XXX]; [XXX] [XXX] [XXX] Date: XXX To: the federal safety agency Office of Defects Investigation (ODI) Subject: Formal Safety Defect Complaint – 2017 Hyundai Sonata Theta II Engine Failure, Excessive Oil Consumption, Intake/Engine Component Failure and Safety Hazard Dear Sir or Madam: I am submitting this formal complaint and request for immediate investigation into the dangerous and ongoing mechanical failures involving my 2017 Hyundai Sonata equipped with the Theta II engine. I believe this vehicle contains a serious manufacturing and/or engineering defect that presents a substantial safety hazard to consumers. My vehicle has experienced a pattern of progressive mechanical failure beginning with abnormal and excessive oil consumption, which appears to be directly associated with malfunctioning engine airflow and intake-related components. Specifically, the lower engine airflow system and intake functionality appear defective, placing excessive strain on the intake manifold system and contributing to cascading engine failures. As a result of these failures, the vehicle has experienced: Severe and excessive oil burning/consumption Intake manifold malfunction and abnormal operating stress Suspected overheating and/or premature head gasket failure Ignition coil failure and electrical shorting/misfires Progressive engine deterioration rendering the vehicle unsafe and unreliable Increased risk of sudden engine shutdown, stalling, fire hazard, or catastrophic engine failure while operating The vehicle has become increasingly unreliable and inoperable due to these conditions. These failures raise significant concerns regarding public safety, especially given the known history of complaints and recalls associated with Hyundai Theta II engine defects. I am deeply concerned that this vehicle may reflect a broader pattern of defective manufacturing, insufficient quality control. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Nov 23, 2024 · Engine, Seat belts · FL

The drivers seat belt does not engage. The engine has been burning oil, misfiring, and even after thousands in repairs was returned to me by the dealership with continued misfiring. When returning the car back to the dealer service center days later after Hurricane Helene, the car continued to misfire and became so overheated the engine light was flashing. Upon calling for a tow, I attempted to raise the hood for the driver to locate the car, but the hood was so hot it burned my hand. The engine was so hot, I believe it was about to catch fire and would have had I not been able to pull over so quickly. Had I been driving on the Interstate, I have no doubt this car would have been on fire within minutes.

Filed Feb 23, 2024 · Engine · KY

Had cruise control set for 75mph, and while traveling up hill, the car downshifted to maintain speed. After 10-15 seconds I noticed power loss and the check engine began to flash. Disengaged cruise control and pulled off onto the shoulder once I found a safe place to do so. As I was slowing down, there was a very noticeable misfire from the engine and was trying to stall out while still in motion. There was no knocking sound, nor was the car overheating. Once I was fully stopped, the car died and would not start back. Had the car towed back to my house. Replaced spark plugs because cylinders 2 and 4 were not firing properly. Also rotated coil packs around to see if they were failing. Cleared check engine codes but they immediately came back to misfires on cylinders 2 and 4. Did compression tests and found that cylinder 2 had 0psi and cylinder 4 had 20psi. Car was not low on oil and no other warning lamps were on.

Filed Aug 15, 2023 · Engine, Transmission · PA

On 12/26/22, I was on a road trip and the car began vibrating violently on the PA turnpike. The car was losing power and would not accelerate. I was forced to stop on the highway with my kids in the car. Hyundai repaired the cylinders in the engine and then it began burning excessive oil, 1 quart ever 1000 miles. For months, I drove this car and as the oil got lower, the car hesitated while driving and ran very rough. On 7/4/23, transmission overheated and once again, car lost power on the road and left me stranded with my kids. Engine is burning excessive oil and causing other issues with car. Was not fixed when car died the first time and has now left me limping along and stranded twice. Car has been at shop since 7/5/23. Engine approved, but dealer can’t get parts. Hyundai won’t approve transmission until engine is replaced, leaving me to drive an unreliable car again when transmission and engine both have known issues. It’s unsafe to continually be stranded by a car that clearly has a bad engine. Would have been more cost effective for Hyundai to replace car at this point and still being given runaround by corporate.

Filed Jul 22, 2022 · Engine, Fuel system · NJ

It's knock sensor issue code was showing since 85000 mileage, dealer just got rid of the code and said can drive safely. Then again at 101000 mileage knock sensor code and Hyundai dealer said software is updated can drive safely. Also it's engine oil burning faster that we keep on topup oil all time. Then at after 108000 mileage my car started overheating, & it's engine seized. Now Hyundai don't want to fix such problems. I don't know maybe it get fixed, then catches fire on highway can cause death.

Filed Sep 18, 2020 · Engine · 14,625 miles · MA

My 2017 hyundai sonata with the 2.4l gdi engine only has 14,689 miles as of today 18 september 2020. It is consuming too much oil and coolant. My engine oil is about 1 1/2 quarts low, with no oil leaks. I had the oil changed at 12,600 miles. Also, coolant is at low level and I haven't driven car much since april 2020 due to covid-19 shut down. No coolant leaks anywhere around the engine, housing or inside. I cannot figure why the oil and coolant are low. My last scheduled maintenance included oil and filter change as well as top off all fluids.