2018 Hyundai Sonata ELECTRICAL SYSTEM,ENGINE

To Whom It May Concern, My name is [XXX] , and I am formally escalating serious ongoing issues with my 2018 Hyundai Sonata. Despite repeated attempts to resolve these concerns through the dealership, my vehicle continues to experience excessive oil consumption, engine failures, and additional mechanical issues, all while under warranty. I am now seeking immediate corporate intervention. Timeline of Events and Mismanagement: •2024(~62000 miles): First reported oil leak and excessive oil consumption. Directed to complete multiple 1,000-mile oil consumption tests. I complied fully. •2024: Repeatedly redirected between service advisors, received conflicting instructions, misleading guidance, and poor communication. No effective resolution was provided. •2025: Completed extensive additional diagnostic testing as requested. Despite full compliance, no clear corrective action was taken. •2024–Present: Vehicle brought to Hyundai on US 19 in New Port Richey approximately 13–15 times for engine-related concerns. Each visit demonstrated neglect, miscommunication, and failure to properly address documented issues. •February 11, 2026: After proper diagnostics, vehicle found to have two additional oil leaks, including a head gasket and valve cover requiring replacement, with total estimated repair costs exceeding $3,000. I was advised I must repeat all testing already completed in 2024 before final determination. •Vehicle is currently at 71,332 miles. Impact: •Delays and repeated unnecessary testing pushed my vehicle beyond warranty limits. •Mismanagement caused significant financial burden, emotional stress, and frustration. •If initial oil consumption issues had been properly addressed under warranty, the current extensive engine failures could likely have been avoided. Immediate Requests: 1Full review of my complete service and diagnostic history. 2Warranty or goodwill coverage for all necessary engine repairs, including head gasket and valve cover INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I first noticed that my vehicle was consuming an excessive amount of motor oil, with the oil change light coming on every 1,500–2,000 miles. I routinely had to add oil between changes to keep it running. On May 30th, while driving on surface roads, I heard clanking noises from the engine. When accelerating, the vehicle clanked heavily, and then went into “limp mode,” limiting acceleration to about 10 MPH before struggling up to 30 MPH. I added oil, but a local shop diagnosed it with code P1326 (knock sensor) and advised that Hyundai engines are prone to failure around 100,000 miles and that I should take it to the dealer for warranty evaluation. I contacted Graham Hyundai, who told me they could not see the vehicle until July 1st and that I would be responsible for towing. I dropped the vehicle off on July 1st, but it was not inspected until July 8th or 9th. I was later told Hyundai was being consulted. Around July 15th–16th, the dealership informed me that I would need $1,500 in repairs. They stated the engine had passed the Hyundai Bearing Clearance Test (a $350 charge) and that Hyundai required me to pay for an ECU “KSD logic” upgrade ($175). They also stated the engine valve cover was leaking, requiring new spark plugs, for a total of $532. Additional charges included an oil change and other shop fees and taxes. After repairs, I was instructed to drive 1,000 miles and then return for an oil consumption test. After approximately 1,000 miles and four weeks, the dipstick check showed the vehicle had consumed nearly all of its oil. I was then told I now need a combustion chamber cleaning, costing approximately $850 and requiring three days in the shop. Given the oil consumption issues, repeated engine warnings, limp mode incident, and the significant costs already incurred for testing and required upgrades, I am requesting that my engine be replaced under warranty and that all fees I have already paid be reimbursed. Rather than keep paying for work.

car turned off at light all lights work and turns on engine won’t roll over the battery and alternator and starter are all good

The electrical and engines in these cars are horrible . The steering wheel keeps locking up while driving cause everything to flick inside the car . This is a major safety issue for me when I am driving and I am unable to control the steering wheel. Dealership claimed they don’t see the issue with the car which I am stating . The vehicle was only inspected by a mechanic and since Hyundai said they couldn’t find anything a 3rd party confirmed that this was a ongoing issue and dealership could’ve caught it but it’s cheaper the sell the car . No everything happens at once especially if I’m turning or driving under 40 mph. First appeared 15 days after I bought the vehicle I alerted the dealership immediately

Car would not start. Odor of burning wires coming from the engine compartment with a little smoke. Had car towed to the Dealer who replaced the starter. Ok for two weeks then same thing. No Start and an odor of burning wires coming from the engine compartment. Had it towed to the Dealer again where it sits today.

Car continues to burn oil within a week of getting oil changes, the oil will be black and it will be low sometimes there will be no oil and there is not an oil leak. Right now we had to pay for a combustion test and have to drive 1,000 miles then check the oil at Hyundai again and already our oil is starting to burn and is low. Hyundai said if the combustion test comes back still burnt or low Hyundai would give me a new engine and yea it’s low and already a tint dark not as dark as it used to get but still it’s low with no leak and we did not get the promised new engine after paying almost 600$ for the test… Also electrical wise the computer randomly sounds like static when Siri talks also the music does not play and randomly the maps will close out we have tried new cords we have tried everything and it still happens.

We were heading to Lakewood NJ from Bucks County (North of Philly) . Car trouble w/ hybrid system on Rt 1, just past I-95. Got off @ Fairless Hills & took back roads. We could only go 20-30 mph. IDK how many times I pulled over. Several lights on, including "Check hybrid system. Turn Engine off", engine light, low tire pressure, battery & 3 other unidentifiable lights. I turned around to try to make it home, as 2 years ago, I had a similar issue, which turned out to be the hybrid water pump failed. We finally stopped near a park & called AAA & towed to dealer. Prior to driving, we had no fluid on our driveway. My last synthetic oil change was April 19, 2023 @ 49,097mile. I now have about 57,000 miles. Today, dealer said no oil in the car & oil pan was all wet. They claim the oil filer was loose. Why would it take 8 months to loosen to lose oil? After adding oil & taking for test drive, they said the engine seized & would need to be replaced. Not under warranty. Add to complaint - the remaining dashboard lights where checked and non of them was for the oil pressure. If I lost enough oil for the engine to seize I would expect a low oil pressure light to come. The dealer informed me on Dec 26, 2023 that when doing the diagnostic, the oil pressure light came on for them. The photos attached to the case does not show the oil pressure light on.

Was driving on freeway on the way back from visiting family in different state when rpms dropped off and suddenly lost power. Car began shuddering and check engine light started blinking. Put hazards on and somehow managed to pull over to shoulder. No problems with car or anything to indicate anything was wrong before this. Called to have car towed to dealership where they said there was a software problem and it was falsely indicating low oil levels. ECM was reset and software updated for $233 which they said fixed the problem. Said that carbon deposits may have caused the software to misread and that may have been why there was no indication of problems before. Hope so because i have a long drive back.

Loss of power on highway or during normal driving possibly due to oil pan assembly according to odi 11481745. This has cause near-miss accidents on highway on ramps a number of times. Separate issue, when the outside temp is at our below 30°F the starter can fail to turn over resulting in a car that won't start even with jumper cables applied.

The incident occurred within my garage when I attempted to start my car and the starter went out producing a burnt smell and spark within motor. After letting the car cool down I put the car in neutral and had it towed to the nearest garage. I thought vehicle could have started a fire inside my garage and home. I have contacted the manufacture and initiated a case incident report awaiting a call back from Hyundai motor company. There were no waring lights or issues with the car the car before incident. The vehicle is under warranty but the dealership stated, they could assist since I took the car to a garage and had a mechanic work on vehicle. The disposition was the vehicle had a faulty started starter, but this incident has a huge safety flag.

TL* THE CONTACT OWNS A 2018 HYUNDAI SONATA. WHEN THE VEHICLE WAS STARTED, IT SPUTTERED AND FAILED TO ACCELERATE OVER 30 MPH. ALSO, THE CHECK ENGINE WARNING INDICATOR ILLUMINATED. THE VEHICLE WAS TOWED TO TITUS-WILL HYUNDAI (255 CARRIAGE LOOP SW, OLYMPIA, WA 98502, (888) 287-9396) WHERE IT WAS DIAGNOSED THAT THE ENGINE AND WIRING HARNESS NEEDED TO BE REPLACED; HOWEVER, THE PARTS WERE ON BACKORDER. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS CONTACTED AND PROVIDED CASE NUMBER: 15586896. NO FURTHER ASSISTANCE WAS PROVIDED. THE FAILURE MILEAGE WAS 22,000.

JUNE 2019, AT ABOUT 11,500 MILES TOOK CAR IN FOR AN OIL CHANGE AND WAS TOLD DUE TO A RECALL, A SOFTWARE UPDATE NEEDED TO BE DONE. AT ABOUT 13,500 MILES, ENGINE LIGHT CAME IN, CAR WAS JERKING IN MOTION ON HIGHWAY AND LOST POWER. CAR WOULD NOT ACCELERATE LAST 62 MPH. CAR WAS SERVICED AND BLOCK SENSOR WIRE HARNESS WAS REPLACED. CAR WAS RETURNED AND AGAIN WHILE IN HIGHWAY ENGINE LIGHT CAME ON, LOST POWER, CAR WAS JERKING WHILE CHILD WAS IN THE CAR AND WHILE CAR WAS IN MOTION. CAR WAS SERVICED AND BLOCK SENSOR WAS REPLACED. AT ABOUT 18K MILES, ENGINE LIGHT CAME ON WHILE ON HIGHWAY AND AGAIN WITH CHILD IN THE CAR AND CAR LOST POWER AND ALSO WAS JERKING WHILE IN MOTION. CAR WAS SERVICED AND ENGINE REPLACED. 3000 MILES LATER, AGAIN WHILE IN THE HIGHWAY, ENGINE LIGHT CAME ON, CAR LOST POWER AND WAS JERKING AND WOULD NOT ACCELERATE. CAR WAS SERVICED AND THE FOLLOWING DAY, WHILE ON THE EXPRESSWAY IN CHICAGO, THE ENGINE LIGHT CAME ON AND THE CAR LOST POWER AND WAS JERKING HARD WHILE IN MOTION. CAR WAS TOWED TO DEALERSHIP IN ROCKFORD IL. AFTER THE 4TH ATTEMPT TO REPAIR, LEMON LAW CLAIM WAS FILED WITH HYUNDAI MOTOR AMERICA WHICH THEY DENIED DUE TO MILEAGE. THIS CAR IS UNSAFE TO DRIVE. WHEN IT LOSES POWER THERE IS NO WARNING, NO BRAKE LIGHTS COME ON TO NOTIFY CARS BEHIND, AND WHILE IN THE BUSY EXPRESSWAY IN CHICAGO WAS VERY DANGEROUS. ALSO DANGEROUS TO HAVE CHILDREN IN THIS VEHICLE. HYUNDAI MOTOR AMERICA REFUSES TO DO ANYTHING BUT REPAIRS AND IS IGNORING THE DANGEROUSNESS THIS PROBLEM. THIS OCCURRED ALL 5 TIMES WHILE THE CAR WAS IN MOTION. THE CODE THAT READS FOR THIS IS 1326 PER THE SERVICE RECORDS.

TL* THE CONTACT OWNS A 2018 HYUNDAI SONATA. WHILE EXITING THE INTERSTATE AT 60 MPH, THE VEHICLE WENT INTO LIMP MODE, JERKED, AND FAILED TO ACCELERATE. IN ADDITION, THE CHECK ENGINE WARNING INDICATOR ILLUMINATED. THE VEHICLE WAS TOWED TO AUFFENBERG HYUNDAI (LOCATED AT 1300 CENTRAL PARK DR, O'FALLON, IL 62269, (618) 622-9001) WHERE IT WAS DIAGNOSED THAT THE NOX SENSOR FAILED AND NEEDED TO BE REPLACED. THE CONTACT STATED THAT THE VEHICLE WAS REPAIRED FOR THE THIRD TIME. THE CONTACT ALSO STATED THAT THE TECHNICIAN RESET THE COMPUTER, THE WIRING HARNESS WAS REPLACED, AND THE NOX SENSOR WAS CLEANED; HOWEVER, THE FAILURE RECURRED. THE VEHICLE WAS ALSO TAKEN TO AN UNKNOWN DEALER IN TX, BUT THE FAILURE CODE COULD NOT BE RECREATED. THE DEALER RESET THE COMPUTER AND REPLACED THE NOX SENSOR, BUT THE FAILURE RECURRED. THE MANUFACTURER WAS NOTIFIED AND PROVIDED CASE NUMBER: 15894913. THE APPROXIMATE FAILURE MILEAGE WAS 15,000.

I WAS EXITING THE FREEWAY AND LOST POWER, COULD NOT ACCELERATE, BLINKING ENGINE CAME ON AND ON MY SCREEN IT SAID "A POSSIBLE CONDITION WITH YOU ENGINE CONTROL SYSTEM HAS BEEN DETECTED. A FULL SYSTEM CHECK RECOMMENDED TO BE DONE WHEN CONVENIENT. PLEASE CONTACT YOU LOCAL DEALERSHIP FOR AN APPOINTMENT" I WAS ABLE TO GET TO AN AREA AND HAVE IT TOWED. THIS COULD OF BEEN VERY SCARY AND DANGEROUS IF I HAD STILL BEEN ON THE FREEWAY DOING 70! I COULD NOT HAVE DRIVEN IT, IT WAS MISSING AND WOULDN'T GET ABOVE 20-30 MPH. I HAD THE KNOCK SENSOR SOFTWARE UPDATE DONE AT THE DEALER THE WEEK PRIOR TO THIS HAPPENING. THE DEALER IS SAYING THE WIRING HARNESS NEEDS REPLACED AND WILL NOT BE AVAILABLE UNTIL THE END OF THE MONTH! MANY ON HERE HAVE WAITED MONTHS I HOPE THAT IS NOT THE CASE. I'VE READ NUMEROUS COMPLAINTS ON HERE AND OTHER SITES THAT THIS IS HAPPENING AFTER THE UPDATE. MY CAR SEEMED FINE BEFORE THEY DID THE UPDATE. SOME PEOPLE NEED NEW ENGINES! HOW DO I KNOW THAT MY ENGINE DOESN'T HAVE DAMAGE, I ASSUME THAT HYUNDAI KNOWS SOMETHING SINCE WITH THE SENSOR UPDATE THEY EXTENDED MY 100K WARRANTY TO 120K. IT SAID THE SENSOR IS TO HELP CATCH POSSIBLE ROD BEARING WEAR AND EXTENDS WARRANTY MUST MEAN THEY EXPECT ENGINES TO HAVE PROBLEMS! WHAT IS GOING ON HERE AND WHY ISN'T THERE ANY OFFICIAL RECALL? MY CAR ONLY HAS 20K I DON'T EXPECT THIS KIND OF PROBLEM. I LEASED CARS FOR MANY YEARS BUT SINCE I'M CLOSE TO RETIRING I BOUGHT THIS WISH I WAS STILL LEASING SO I COULD GET OUT FROM UNDER THIS IN 2 YEARS!

ON 03/23/2019, WHEN I WAS LEAVING A PARKING LOT MY CAR STARTED TO HESITATE AND WOULD NOT REV UP. I JUST TURNED OUT THE PARKING LOT WHEN THIS HAPPENED. MESSAGE CAME ON STATED IT NEED TO BE SERVICED. AT THE SAME TIME THE ENGINE LIGHT CAME ON. I WAS NOT ABLE TO PRESS THE ACCELERATOR BECAUSE IT WOULD JUMP LIKE CRAZY. I WAS ABLE TO GET BACK TO THE PARKING LOT SAFELY. I HAVE BEEN IN A RENTAL FOR A MONTH NOW AND AS OF 04/23/2019 I WAS TOLD THE PART IS ON BACK ORDER. THE WIRING HARNESS AND THE COMPUTER HAS TO BE REPLACED, BUT THE TECH STATED SINCE THE CAR WENT INTO LIMP MODE THE ENGINE WILL NEED TO BE REPLACED. I WAS TOLD THE PART WILL BE IN ABOUT 3 TO 6 MONTHS. IF THE WIRING HARNESS DOES NOT WORK GOD ONLY KNOW HOW MANY MORE MONTHS IT WILL TAKE FOR A NEW ENGINE TO ARRIVE. THIS CAR WAS ONLY 9 MONTHS OLD BUT NOW 10 MONTHS OLD WITH ONE OF THE MONTHS BEING IN THE SHOP WAITING FOR REPAIRS.