general problems of the 2016 Hyundai Sonata - part 1

I am filing a complaint against Hyundai motor America regarding denial of defect coverage for my 2016 Hyundai Sonata (VIN: [xxx] ). The vehicle is experiencing excessive oil consumption and triggered diagnostic code p1326. The dealer confirmed only one quart of oil remained in the engine and noted a valve cover gasket leak. Hyundai’s tech line instructed a gasket replacement and oil consumption test, but Hyundai corporate formally declined coverage, citing mileage and second-owner status. This is not a routine warranty claim but a defect claim. Oil consumption defects in Hyundai theta engines are well-documented and have been subject to recalls, technical service bulletins, and class actions. Defect coverage should not be limited to first owners. I am requesting reimbursement for the valve cover gasket repair, acknowledgment of the oil consumption defect, and corrective action to ensure Hyundai honors defect-related coverage fairly. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My Hyundai is experiencing severe and continuous engine oil consumption that creates a safety risk. The vehicle loses a significant amount of oil within 1,000–1,500 miles, sometimes showing almost no oil on the dipstick despite recent oil changes. There are no external leaks, no burning smell, and no visible oil under the car. The cause remains unknown, but it appears to be internal engine burning or a manufacturing defect. I have taken the vehicle to the Hyundai dealer multiple times. They performed oil consumption tests but either reported “normal results” or did not provide clear explanations. The issue continues exactly the same. I also contacted Hyundai corporate, but no meaningful assistance or goodwill support was provided. The dealer acknowledges no leaks but still refuses to repair or replace the engine. This problem is dangerous because the oil level drops without warning lights or error codes. If I do not manually check the dipstick, the engine could run dry and seize while driving. Sudden engine failure on highways or in traffic can cause accidents. I now have to frequently top up oil just to keep the engine alive. I have maintained the vehicle properly and completed all requested tests. The cause is still unknown, but based on similar Hyundai cases, it may involve piston rings, valve seals, or internal engine wear. Many Hyundai owners report the same issue, suggesting a broader defect. The dealer’s only advice is to “keep monitoring oil,” which is not a safe long-term solution. This defect poses a serious safety concern and financial burden. I am filing this complaint so NHTSA can investigate, as the engine may fail unexpectedly, putting me and others at risk.

On November 10, 2025, my 2016 Hyundai Sonata hybrid (VIN [xxx] , approximately 150,000 miles) experienced a sudden loss of power while I was turning right and accelerating into traffic. The vehicle immediately entered limp mode with flashing warning lights and audible alerts. The vehicle lost normal propulsion and could not accelerate properly, creating a dangerous situation as it was blocking a traffic lane. I was forced to limp the vehicle into a nearby parking lot to get out of traffic. The vehicle was not safely drivable afterward and was towed home. A few days later, the vehicle was towed to murdoch Hyundai in lindon, utah, for diagnosis. The vehicle was found to have diagnostic trouble code p1326, which Hyundai identifies as activation of the knock sensor detection system (ksds) related to connecting-rod bearing wear. This condition is part of Hyundai’s known engine defect and safety recall/warranty extension programs. During inspection, the dealer observed that the valvetrain did not show signs of neglect or sludge, which is inconsistent with oil starvation or severe maintenance neglect. This further supports that the failure is consistent with the known connecting-rod bearing defect addressed by Hyundai’s ksds safety recall, rather than a maintenance-related issue. This is a safety issue because sudden loss of propulsion or reduced power while entering traffic creates a high risk of collision. Hyundai customer care has been unwilling to open a new case number or escalate review, and the dealer has indicated possible denial of engine replacement coverage based on incomplete oil-change records, despite the vehicle exhibiting the ksds safety condition. I am requesting NHTSA review of this safety-related defect and the manufacturer’s handling of ksds/p1326 failures. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My 2016 Hyundai Sonata with the dohc gdi theta-ii engine is experiencing severe engine oil consumption consistent with Hyundai's known txxi/txxc extended warranty defect. The oil pressure warning has flashed while driving or braking, the engine runs rough when slowing down, engine has made knocking noises, and there is smoke/vapor with a burnt oil smell when removing the oil cap after driving. The oil level drops rapidly between changes despite proper maintenance. This issue poses a risk of engine failure, stalling, or fire while driving. I have maintained the vehicle on time with all oil change receipts. A Hyundai dealership refused to perform the required warranty diagnostics even though this issue falls under Hyundai's extended warranty for theta-ii engines. This is a serious safety concern, and no corrective action has been taken.

The vehicle is going through oil very quicky. No leaks no burning.

The vehicle experienced an engine and power train failure while driving on the highway, resulting in sudden loss of power. The electrical system also failed after the dealer visit, causing the battery to die every morning. Yes, the vehicle is available for inspection upon request. My car suddenly lost power on the highway and would not accelerate, forcing me to pull over on the shoulder with traffic moving around me. This created a serious risk of a rear-end collision or crash. Additionally, after the dealer visit, the electrical system began failing and the vehicle has been completely dead every morning, leaving me stranded with a child and unable to reliably start the car. The problem has not been reproduced because the check engine code cleared itself after the incident; however, the symptoms absolutely remain. The dealer refused to diagnose the loss-of-power event because the code was cleared, and they returned the vehicle to me with a dead battery. The electrical issue (car dying every morning) has been happening consistently since the dealer visit. The vehicle was taken to a Hyundai dealership immediately after the incident, but they refused to diagnose the loss of power due to the code being cleared. A mobile mechanic scanned the code at my home before the tow, but the code disappeared afterward. The electrical failure began after the dealer visit and has not been properly inspected by Hyundai. Yes. While driving on the highway, the check engine light came on and the car immediately lost power and would not accelerate. After the dealer visit, the car has been completely dead every morning and requires a jump to start. These symptoms began on the same day as the highway incident and continued after Hyundai serviced the vehicle.

Engine issue - but no recalls there have been hundreds of this same car yr and model with engine issues out of the blue.

While driving, my 2016 Hyundai Sonata’s engine suddenly started knocking loudly. I stopped immediately and found the engine oil was very low without any prior warning. After adding oil, the engine still runs but with possible internal damage. This could have caused the engine to seize while driving. There were no warning lights or leaks before this happened.

My 2016 Hyundai Sonata experienced a sudden engine failure while in operation with no prior warning lights or symptoms. The engine seized unexpectedly, creating a safety risk. This failure appears consistent with known engine defects affecting Hyundai Sonata vehicles of this model year. Hyundai motor America denied my claim without addressing these known defect patterns.

High engine oil consumption 2 qts every 1k miles.

Sudden engine failure. Compression issue, car has only 63,000 miles.

Car had oil in the electrode of spark plug. Total engine failure.

The problem with my vehicle is a failure of internal engine components, specifically a known defect in the piston rings of the Hyundai theta ii engine. This failure causes excessive oil consumption, which is burned internally. The internal engine components have failed, leading to a widely documented defect in the Hyundai theta ii engine. The primary symptom, which began to get serious around 80,000 miles, is the constant need to add oil to the engine every two weeks. If I do not do this, the low oil warning light illuminates on the dashboard, serving as a continuous alert of the problem. This failure was officially confirmed by an authorized Hyundai dealership. About two weeks ago, they first documented that there were no external leaks on the vehicle. When I returned because the oil had been consumed again, they performed a new diagnostic, for which I paid over $300, that confirmed the engine is burning oil internally. The dealership, acting as the manufacturer's representative, is the only entity that has formally inspected the vehicle. The situation places my safety and the safety of others at serious risk. First, the oil consumption can lead to a sudden and catastrophic engine failure, resulting in a loss of power and control of the vehicle while in transit. More alarmingly, the guidance I received from Hyundai staff was to simply "wait for the engine to stop working or start making a lot of noise. " as someone who depends on the car for a daily commute, following this dangerous recommendation is an unacceptable risk.

Was driving on the interstate, and took the exit I needed. Upon exiting before coming up to stop light, noticed check engine light flashing, and couldn't accelerate. Rpms were bouncing when I tried to accelerate. Pulled off onto side of road, called mechanically inclined friend who came with an obd2 sensor, and it was showing a p132600 code for knock signal range performance, with an audible knocking sound, and engine vibration while on in idle. Got the code cleared so we could drive the car the 3 miles I needed to go to get to where I was going, 2 miles in, the engine light came back on and vehicle went back into limp mode. Called aaa and got the car to an in network mechanic shop for carvana, whom I bought the car through a month prior. Proceeded to do an oil sample test and found it to be full of metal shavings. Said engine would need to be fully replaced. Vehicle is currently still at mechanic until silverrock gets the claim and will see if the engine replacement is covered under warranty. Certified automotive inc. [xxx] [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My 2016 Hyundai Sonata (VIN: [xxx] ) had its engine replaced under recall campaign 20v746000 in March / April 2024 at Hyundai of round rock, TX. In October 2025, less than 18 months later and at 97,000 miles, the replacement engine failed again. Hyundai has refused further repair, citing an expired recall warranty. This raises serious safety and reliability concerns, as a recall engine should not fail this soon. Engine failure while driving could result in a stall or crash risk. Please investigate whether Hyundai’s recall replacement engines are defective and if extended coverage is warranted for affected consumers. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

At 70712 miles cylinder 4 suffered a catastrophic internal failure. The vehicle also had excessive oil consumption and the dealer just told us to keep adding oil as there was nothing they could do. The vehicle must have had a manufacturing defect.

Vehicle stalled while driving.

Engine failure and car burning oil very fast causing other things to go wrong like piston ring and spark plugs.

I bought this vehicle on 07/21/2025,I didnt recieve any information about recalls,I was driving on 80 east at 60 mph and noticed the dash lights came on, somehow I was able to coast far enough and merge 2 lanes and was sitting between the offramp and the freeway ,the seemed like a dead battery or wouldnt turn over, soon a California state tow truck pulled up he tried to jump it ,nothing, he towed me to a safe place, then I called triple a same thing, I was towed home after I assumr the crankshaft cooled it started with a knock, there was no knock when it siezed, I got home and seen they gave me gwc warranty, im paying for they didnt even mention that when I bought it, ,the story is worse this was the second car from this dealer,the first one I had 1 day and heard rods knocking on cold starts I took it right back, thats how they got me in this I was kinda cornered, I called gwc they said send it to a dealer so I sent it to Hyundai ,at first they told me the engine siezed and said its covered by Hyundai, then said the next day they denied it becouse the knock sensor update was never completed from 2020,I only had the car 1 month it siezed on 08/25/25,so now there trying my gwc coverage who tells Hyundai they will cover a used engine,I said ok, I have been communicating with the Hyundai service manager, he did tell me over the phone he doesnt believe it was even legal for them to sell me that car,also yes the blinkers did constantly go the wrong way,I didnt know about that recall either I know it was upsetting me,every time I look my blinker was going the other way,,I see lots of recalls and problems with the Hyundai engines,how do I realy know if that was or wasnt taken care of for this car or was there a knock sensor recall in 2020, the car has 144,000 miles I bought it with 141,051, Hyundai warranty becouse engine siezure is 150,000, its still sitting at Hyundai waiting for gwc to say go ahead ,he keeps telling me they will let me know tomarow,I have no car,.

Pushed acceleration at traffic light to cross and turn into neighborhood, car started beeping frantically, 'check hev system' flashed on dash as well as 'turn off engine' while car decelerated to 1-3 mph. Battery meter bar on left side of dash completely depleted showing no battery power supply at all. Turned vehicle off for a few minutes then restarted. Put the vehicle in drive gear and same warnings appear, car doesn't even accelerate when gas pedal is pressed fully, stays at 1-3 mph crawl. Vehicle stalls out after 30 seconds, vehicle turns on but cannot start.

I was going down the highway and noticed a weird sound and when off the highway it just shut down on me thank god I was able to pull in a median and I could not drive or start it. No other warning signs. I had it towed to a mechanic and they told me the engine was blown and he wouldn’t touch it.

On [xxx] as I was driving out my garage my car started to drive with hesitation. As I turn the corner from home my car started to shake vigorously so I turned into the alley which leads back to my home the check engine light came on. I was able to drive into the garage. So I went to a mechanic who has serviced all my previous cars and he showed me that the car is burning too much oil that was effecting the performance of the engine making it drive sluggish I was also told at the oil changing company in numerous occasions that the Sonatas burn oil. I’m trying to get it resolved but having no luck . It’s a real hassle with servicing this car. I need assistance on what I need to do information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My check engine light came on and my car went into “limp mode” and wouldn’t go above 30 mph. It also kept blowing hot air through the vents and the coolant level thermometer kept raising.

This car burned oil like crazy from the start. We kept the oil changed regularly, had to change spark plugs weekly and add a quart or more of oil each week in between oil changes. One day whole stopped at a red light the engine started knocking for no reason. Once diagnosed it turned out that it had spun a rod bearing. These engines need to be recalled before someone ends up in a fatal accident. This car was driven daily on a major interstate thankfully the issue happened at a red light, but has left me with a car note and a non drivable car. What’s it gonna take to get these engines recalled and replaced?.

Engine failure. Happened in the middle of the beltway in DC. Was left in the middle of traffic had to get car towed. No lights were on prior to this happening. Seems everyone I have talked to with a senata has had engine failure and has ultimately got a new one replaced by the delorship. The 2016 isn't on the recall list only models 2011-2014. But I have heard of numerous 2015-2016 models having the same issue. This car barley had 110k miles on it before the engine failure. These vehicles are not safe and there needs to be something done. It is currently being looked at by delorship. Im hoping for the best.

The engine began knocking on us, towed to dealership. Safety concern was dying on the highway with other cars around. The dealer said it needs a new engine. Not sure there were any indications of failure or not. Some records indicate in order for Hyundai to warranty, this car needed to have had campaign 953 ksds installed prior. Some records such as the tg3 txxi warranty state that in April 2022, the ksds campaign update was no longer required for the Hyundai theta ii engine warranty. Owner did not perform ksds 953, based on not receiving the information. Hyundai is currently denying warranty, but if tg3 txxi is correct, the dealer has yet to fully inspect, and the fact remains that in April 2022 the campaign 953 is no longer a prerequisite. I dont feel like I should be denied assistance. Please help.

Driving and engine began to tick, for a couple minutes, then died. Would not restart.

While driving on the highway, experienced loss of power and flashing check engine light, subsequently causing engine knock and engine failure. This situation could have caused an accident and put myself and others at risk. It is understood the manufacturer has recalled more than one million vehicles due to engine failure and is working with NHTSA to address the issue. In communication with the manufacturer to inspect the damage and resolve the issue.

This vehicle has a faulty engine design which results in extreme over-consumption of oil. After an oil change, the engine will typically empty in less than a month, which is beyond a reasonable level of oil consumption. Side effects of this include other parts of the engine wearing down quicker, including the spark plugs, which cause engine misfires. Ultimately, this vehicle's engine design causes financial hardship to it's owners and poses a potential safety risk to those who drive in it. I believe Hyundai should do a recall to fix this faulty engine (with an engine replacement if necessary).

Engine consumes excessive amount of oil, approximately 5 quarts every 1,000 miles. No leaks found when taken for inspection.

There is an oil problem with this car - my engine light keeps going on, then it backfires, I brought to the dealership and $2,800 later, I still have the same problem. There is no leak that I can see, the oil just disappears. My mechanic said this is a known problem but hyandai will not get back to me, I have tried several times with no interaction back.

Rod bearing failed at highway speeds, loss of power and flashing check engine light only after engine failure. This could have caused an accident putting myself and others at risk of bodily damage had I not been able to pull off of the freeway. Engine knock/rattle, eventually leading to catastrophic engine failure. This has been confirmed by a third party trusted and certified technician at an independent shop. Currently in the process of having the damage inspected by the manufacturer.

The engine stopped as I was driving on the road.

I had knocking in the engine from the auto body shop and my extend warranty told me this is the problem that I have.

My car has 123,000 miles on it, it started with just aircon compressor not working then a week after the engine light started blinking and doesn’t accelerate more than 60 in the interstate then there is a rod knocking in my engine after that.