I was driving about 40mph and out of nowhere my engine shuts completely off. I have the vehicle towed to the local Hyundai dealer, and they notified me after 78000 miles my engine has seized. I just had a oil change about 30 days prior. After a little research I found this to be a common problem. I am discussed.

- Willingboro , NJ, USA

The contact owns a 2011 Hyundai Sonata. While driving approximately 2 mph and depressing the brake pedal to stop the vehicle, the engine suddenly shut off and failed to restart. The vehicle was towed to the dealer who indicated that the engine seized, but the cause of the failure was not determined. The manufacturer was notified of the failure. The failure mileage was 91,000.

- Simi Valley , CA, USA

The contact owns a 2011 Hyundai Sonata. The contact stated that the air bag light intermittently illuminated. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was 112,000. Updated 6/8/15 the consumer also stated a month after getting an oil change, the oil was low and she had to add more oil. Updated 06/11/15

- Winston-Salem, NC, USA

I have a 2011 Hyundai Sonata, my first car I purchase it almost 4 months ago I'll had 2 oil changes including the one the dealer did before I bought it. I was simply driving home & heard a weird noise so I pulled over my battery died and car engine started to smoke I was giving no warning sign or indicator to check my oil or anything. I had my car towed to suntrup Hyundai were I was told my engine was seized and would cost me from 5,000-9,000 for a new or used. How does a well-maintained car go from normal to a total lost" I'll done my research so my question for you is when will you recall this entire car" will indeed be joining the class action lawsuit against Hyundai. I have no warranty & don't even want the car with a new engine. I just want Hyundai to buy the car back it's a serious safety risk I'll stick with american made vehicles.

- Saint Louis, MO, USA

The engine is knocking when I start to drive and the knocking sound has gradually increased. I have to put 1-2qts of additional oil into the car in between scheduled oil changes.

- Woodstock, GA, USA

I am having problems with my car not wanting to accelerate sometimes, I typically notice this when I am on the freeway going about 60 mph and when I try to go past that it will seem to not want to accelerate and then jerk and then go accelerate faster. Lately I have also notice this when going normal speeds it seems like it wants to stall.

- Houston, TX, USA

Went to take off from a stop sign and noticed I did not have the power it usually does. Drove appr 3 miles, came to a stop light. The oil light came on and the car stalled. Started the vehicle back up, drove appr 3/4 mile to the nearest gas station with flashers on and <20 miles per hour, all the while the car was hesitating and knocking/tapping. I called my husband who came to get me. We checked the oil and it was barely registering oil. We purchased 2 quarts and drove the car appr 2.5-3 miles home. The next day my husband drove it down the road about a mile. It was running very rough with knocking/tapping and hesitation. Then the check engine light came on. He called the Hyundai dealer and had it towed as we were still under warranty. Their diagnosis was no oil, lack of maintenance yet there was no oil leak or burning of oil. Since this is "our fault" according to the dealer, it will not be covered under warranty and we need a new engine at $6,000+. we have done regular maintenance on it since we purchased it Sept 2014 - 2 oil changes in 7 months, the last change being the 1st week of January. My husband does our oil changes (he used to work at Goodyear and has done oil changes since he was a teenager) so we have no receipts from oil purchases at walmart.

- Pittsboro, NC, USA

I was driving on the highway (295 South towards Washington DC) and when I tried to accelerate, nothing happened. When I examined the dashboard, all of the lights were on. As a precaution, I pulled over to the shoulder. After bringing the car to a stop I noticed a burning smell. After opening the hood I discovered smoke coming from the engine area. I tried to start the car but to no avail. I immediately called roadside assistance and the car was towed back to pohanka Hyundai in capital heights md. After an inspection of the vehicle, the technician discovered no oil was found on the dip stick and the engine had locked up! as I pulled up my last oil change record it showed I received 5 qts of 5W20 synthetic blend oil at 110,641 miles. I told the technician that I never had any leaks or knocking sounds. Also I never had my check engine light illuminate. It amazed me how after 5000 miles no oil was in engine and I had no apparent and visible leaks.

- Odenton, MD, USA

The cars ignition key does not release from the ignition for up to 6 hours. The ignition cylinder was changed by Hyundai but the problem continued to happen even with the change of the keys and the cylinder. Also, the engine seizes when I took my son and his girlfriend to the airport. Hyundai did not honor the warranty and charged me $3600 for a new engine. Their 10 year warranty is a fraud. I had to pay for the key change which did not work.

- Richmond Hill, GA, USA

I was making a right turn when the vehicle stopped. I could not restart it and had to have it towed. When the vehicle was inspected I was informed that the engine has seized. There was never any oil or check engine light that came on. The oil was changed when it should be.there was oil in the engine. Since the warranty was up I had to come out of pocket for an engine..

- New Orleans, LA, USA

My wife was driving the car than all of a sudden she thought she heard a muffler sound like a rattling sound. She checked the muffler but the muffler was intact. Than as she was driving the car idled low as if it wanted to die. Than she got out at a parking to investigate the sounds turns out the engine is knocking bad. I call to get vehicle towed to Hyundai. Before they received the vehicle a service employee tried to tell me that the maintenance of the vehicle is determined also by the previous owner and how well he maintained it in order for the warranty to be valid (my vehicle is precertified it has 44487 miles and oil change is due at 44906) and the vehicle will not be looked at for a week. I called another dealership because I knew the employee was lying to me and the other employee at the different dealership assured me that the warranty starts with me and the previous owner has nothing to do with it. So I am waiting to hear back to see what they will do regarding the warranty. I know a knocking engine is a severe matter and the fact they lied to me before looking at the car already seems as if things are to just get worst in regarding with dealing with them.

- Lancaster, PA, USA

Driving down hwy @65mph. Car lost power. Was able to get to side of road. Car smelled and smoking. Checked oil...2 liters low. Had oil changed 1000 miles ago. No oil light came on. Have been routinely checking my oil because 2 weeks after oil changed had car serviced for brakes and mechanic checked oil and was low. He put oil in. No oil leaks anywhere. Now I have to pay 4500 for another 2011 Hyundai Sonata engine which I really don't want to put it because there is obviously a problem with this engine and replacing with the same I will end up with the same problem.

- Coraopolis, PA, USA

Was driving the car when I noticed some "clicking" noises coming from the engine. I immediately began experiencing severe engine power loss and, as I was on my way home from work and a local Hyundai dealer was nearby, I went there. Upon arrival, I advised the service person of the symptoms I'd experienced. After a call from the dealer the next day, I was advised that Hyundai wanted them (the dealer) to completely tear the engine down to take pictures of the internals to assess the damage. The representative also told me that the oil was extremely low on the dipstick, so low that it didn't even register. Note: The car was next scheduled to receive an oil change at 57,600 miles, and this occurred at 56,000. A few days later, I hear back that "Hyundai" had declined the warranty coverage, so I contacted Hyundai and they stated that the dealership is the one who had in fact denied the warranty coverage, and would be contacting them to understand the reason(s) for the denial. After researching the issues, I've found a lawyer opening a class action lawsuit, as others have reported this same issue. Lawyer: www.chimicles.com/2011-Hyundai-Sonata-engine-failure-class-action-lawsuit?post-subscriptions-status=subscribe complaints: www.carcomplaints.com/Hyundai/Sonata/2011/engine/engine_seized.shtml.

- Caledonia, NY, USA

Was taking left hand turn on major road, and all of the lights lit up inside the vehicle and the engine just died. I pulled over to the side of the road and had all electrical systems but the engine would not turn over. I popped the hood and saw smoke from the engine, so checked the oil and there wasn't any on the dipstick. Had to call a tow truck to have vehicle taken back to the last place I had the oil changed. They determined that the engine had seized up and that I needed to replace it for $7000. No check oil engine light came on and always had oil changed on regular basis, because I do a lot of highway driving for work.

- Clayton, NC, USA

This car is equipped with a smartkey. Recently it has developed a starting problem that is directly related to the outdoor temp. It has been serviced several times by the local Hyundai dealer. They have replaced the shift interlock switch and the brake light switch. It is below zero this morning (2/21/2015) just one day after the brake light switch was replaced, and again the car refuses to start. When the start button is depressed everything lights up on the dash board but the engine will not even turn over, it is completely dead. The engine imobilizer light also comes on after attempting to move the shifter and the brake pedal becomes nearly impossible to depress! the car will be out of warranty soon. This needs to be resolved. The car has refused to start dozens of times with the very same issues. The car has left me stranded (at home to date) numerous times. When it warms up outdoors later in the day and the temp goes up to 25 - 30 degrees the car starts virtually every time and will start without a problem for the rest of the day. I have researched this problem on this website and other websites and push button ignition problems are very common on this car. Hyundai needs to come up with a proper fix for this problem. Numerous people report having the same switches replaced as on my car their problems were not solved either. It appears that Hyundai has never been able to come up with a proper fix for this issue or it is just to costly to implement. They have continually swept it under the rug.

- Colchester, CT, USA

I was driving on the interstate 2/14/15 and started to slow down due to traffic. As I slowed to approximately 25 mph, my car died. I had enough momentum to make it over to the right shoulder. I had my vehicle towed to the local dealership who stated that my starter had gone bad on 2/14/15. I waited to hear back on Monday, 2/16/15 that they had fixed the starter, but instead they called and stated that my engine had seized up and I would need to purchase a new engine for $5600 (including labor). I made regular oil changes (I was not exactly 8,000 miles for every oil change though), I completed all recall requirements, I had my oil pan replaced Dec 2013, I had the car looked over 100% Dec 2013 and it was found to be in great working condition, & my engine actually turned over when it died on 2/14/15, so the starter made sense. I did some research, and it appears there is a class action lawsuit for ~ 30 incidents where the Hyundai engine seized on this year, make, & model. I am very frustrated that I have to pay for an engine that is pretty much what the car is worth now, when an engine should not seize up after only 120,000 miles when taken care of properly. The fact that it stopped while I was still driving is extremely unsafe and could have easily resulted in a wreck. I believe that the engines on this year, make and model should be investigated and should be recalled due to safety reasons.

- Easley, SC, USA

I was driven on the highway in the 2nd to left lane about 70 mph, check engine light was on and all of the sudden I lost complete control of the accelerator pedal. I pushed it all the way down to the floor several times, no pressure, no control and obviously slowed down. I moved over to get to the right shoulder to stop and see what is the issue, luckily the brakes worked, but many cars were dodging me trying not to hit me. I didn't get in an accident, but sure close to being in one and high speeds. Frightening to say the least. I did make it to the dealer and come to find it is an emission part that failed that caused the car not to accelerate. I did get it fixed but was out of warranty, and past the federal emission reimbursement program of 8 years or 80K miles. I had about 80,200-500 miles on the car. Coincidence, don't know, I am still concerned driving the car, it could happen again! I am just glad I didn't get seriously injured or killed. I didn't get reimbursed for the part that cost $1,500. But I am very concerned knowing that this could happen to anyone with emission controls by the computer in your car. I tried to be proactive therefore the post complaint for others. I guess it takes collateral damage of people losing life for car companies and the wonderful federal government to take notice. Beware most new cars have these systems from what I am told.

- Leesburg, VA, USA

The contact owns a 2011 Hyundai Sonata. The contact stated that while making a right turn at 20 mph, the vehicle stalled. The contact was able to restart the vehicle by shifting into park and reinserting the key into the ignition. The vehicle was taken to a dealer. The technician diagnosed that the oil pump needed to be replaced. The vehicle was not repaired. The failure recurred on numerous occasions. The manufacturer was not notified of the failure. The failure mileage was 77,000.

- Toms River, NJ, USA

Purchased a brand new 2011 Hyundai Sonata. While we were driving down the road, we heard a knocking noise coming from the engine. While we were looking for a gas station to pull over, the check oil light came on, all within a matter of minutes. We immediately pulled over and checked the oil only to find that no oil was registering on the dip stick. We found that odd as we had our oil change just a couple months ago. Had the car towed to the dealership and was told that there was sludge in the engine and we needed to replace it. The cost to replace the engine was $6100. Furthermore, the dealership went on and changed their story 5 times as to while the engine failed. They asked us to provide them with oil change receipts, which we did yet they still denied our claim. Our car had the oil changes done properly and within the time scheduled. Our car was still under warranty yet they denied our claim we have filed a lawsuit against the dealership and Hyundai.

- Riverview, FL, USA

I was driving down the highway, the engine started making a knocking noise. No less than 30 seconds later did the car's engine make a large bag noise and I ran over what felt like parts. I coasted a while down the road and finally pulled the car over to the side of the road. Upon opening the hood I discovered oil all over the intake and exhaust manifolds as well as the radiator. I called Hyundai roadside assistance and had the car towed to faulkner Hyundai in harrisburg pa on 1/19/14. They provided a service loaner and said they would get back to me with an update on the car. I waited until Wednesday the 21st before calling them, only to find out that the engine had seized and they had already taken pictures of the damage and sent them to the Hyundai people to seek warranty coverage. They also asked me for maintenance records on the car. I change the oil myself and always put in full synthetic, so they had me submit receipts from the auto parts store proving I bought oil and filters or the Sonata. I am now awaiting resolution from Hyundai. Will update once I have an answer from Hyundai. This is a pretty serious safety concern, the engine let go at 60+mph without warning, when it let go it blew oil all over the engine compartment and I'm sure on the road as well. Lucky I was driving early in the morning and their was very little traffic.

- Shawnee, KS, USA