CarComplaints.com Notes: The 2011 Sonata has a seriously defective engine that seizes without warning. It was awarded the dubious honor of being the first CarTalk / CarComplaints Turd of the Week in late September 2015.

A class action lawsuit was filed in May 2015 against Hyundai that claims the 2.4L Sonata engine is defective. More info here.

10.0

really awful
Crashes / Fires:
2 / 1
Injuries / Deaths:
1 / 0
Average Mileage:
12,995 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2011 Hyundai Sonata engine problems

engine problem

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2011 Hyundai Sonata Owner Comments (Page 2 of 2)

« Read the previous 20 complaints

problem #12

Aug 312011

Sonata 4-cyl

  • 1,604 miles

A D V E R T I S E M E N T S

Loss of power, car shuts down, 'check charging system' alarm/chime with alarm symbols on dash display for battery, check engine and wrench icons. Have to pull off the highway somehow (in midst of heavy traffic) to shut car completely off and restart. On third incident (one day after second), car would not restart for 10 minutes and check engine icon remained lit. Every incident has been while traveling at high rate of speed in commuter highway traffic. Very frightening and dangerous experience for driver and safety hazard to others when it occurs.

- Medina, OH, USA

problem #11

Sep 062011

Sonata 4-cyl

  • 6,000 miles
Upon pulling out from a stop sign the engine stalled, after coasting to a stop and placing in park I tried to restart engine. All lights went off and motor did not turn. Attempted again, same thing then passenger compartment filled with smoke. Fire dept arrived and determined somewhere in dash a component had fried.they then disconnected battery. Vehicle was towed to dealer, per dealer engine locked up and they have to disassemble dash to determine what had fried.

- Pittsburgh, PA, USA

problem #10

Sep 062011

Sonata 4-cyl

  • 2,440 miles
When pulling out of a parking lot from a stop the service light came on and the car's ready light started flashing. The car lost almost all power while I was in the center of the road. Other cars were able to avoid me, but they could have easily ran into me. Shutting the car off and restarting it restored normal operations.

- Burnsville, MN, USA

problem #9

Sep 012011

Sonata

  • 7,093 miles

A D V E R T I S E M E N T S

Sonata hybrid. Driving on the freeway at 60 mph on cruise control. Exit ramp with cruise control off and car gliding to stop light in ev mode. Stopped at red light for 3-5 seconds. Then pushed the accelerator... the car lost power, would not move, instrument panel lights flashed, audible ding warning sounded. Display screen showed "check charging system" then screen showed to put car in park. I then placed car in park and pushed the ignition button and car had power to drive off the street and out of the flow of traffic. I then looked over the car, no warning lights or sounds. I test drove it in a parking lot to make sure it would not stop again. Conditions at time of event: Blue driving mode, gas tank level at 1/2, hybrid battery charge at 1/2 radio on, headlights on, air conditioner off, and the outside temp. About 77F. I'm not sure which component failed. Electrical, engine or the hybrid power control unit.

- Morrow, OH, USA

problem #8

Sep 012011

Sonata 4-cyl

  • 6,700 miles
2011 Hyundai Sonata hybrid stops loses power comes to complete stop - for the second time in two months when I started my car the service indicator light came on and stayed on. I noticed this time that the car would not go faster than 40 mph and the engine is not running the car appears to be running just off the electric motor and the battery. The car went for about 2 miles and the car lost power and came to complete stop. I had to completely shut off the car and restart it before it would move again.

- Las Vegas, NV, USA

problem #7

Aug 022011

Sonata

  • 17,500 miles
2011 Sonata limited with smart key fob has failed to start a minimum of 7 times in the last 60 days.it appears that sometimes the car does not recognize the smart key and this doesn't change if the smart key is inserted into the center console smart key holder. The batteries have been replaced in the key fob and this does not resolve the problem. When attempting to start the car the computer simply states to depress the brake pedal and push the start button, which I've been doing. The brake pedal often feels hard as a rock almost like it's locked.the normal diagnostic lights and fuel guage does operate but the car doesn't start. I've waited as long as 1/2 hour attempting and re-attempting to start the vehicle. After it starts, the car may work perfectly fine for the next few trips until the problem reappears. This is a worrisome occurence since there is no way to override the smart key fob by inserting an actual key to start the vehicle. Drivers may become stuck at any time.

- North Potomac, MD, USA

problem #6

Aug 152011

Sonata 4-cyl

  • 6,000 miles

A D V E R T I S E M E N T S

Hyundai Sonata hybrid stops loses power comes to complete stop - while driving down the road at about 40 mph car lost power and came to complete stop. I had to completely shut off the car and restart it before it would move again.

- Las Vegas, NV, USA

problem #5

Jul 072011

Sonata 4-cyl

  • 2,217 miles
Engine can easily become hydro-locked in heavy rain and road splash back from other vehicles due to the design of the direct air intake of the Sonata hybrid. With its design, it does not have any water baffles to prevent water from entering the air filter and once it enters the air filter box, there are no drain holes for it to drain out. This forces the water through the engine as that is the only way for it to get out of the filter box. When the engine stalled, no electronic control warning lights were illuminated and the car remained in the 'ready' state. This could lead to damage of the hev system and battery pack. Per the technician servicing the car, they stated that the hev warning light only illuminated when the hev battery reaches 15% charge (the point at which they have to replace it), this contradicts with the owner's manual as well as counteracts the purpose of a warning lamp. Due to the nature of the design where the computer controls when the engine start/stops, the engine can damage itself before preventative action can be taken. For example, when the engine stalls due to water ingestion through the air filter and the oxygen sensor determines it cannot compensate, the engine will stall, but before the situation can be rectified, the computer attempted to restart the engine causing it to become hydro-locked. With my experience, I am convinced that the design of the car is flawed and is unreliable to drive in a heavy rain scenario which leaves it unusable several times a year. I have owned several hybrids in the past (2001 and 2005 Toyota prius) that I operated through the same conditions as your vehicle and I did not experience any problems with them. Additionally, with the Toyota, when the engine stalls against the computer's control (e.g.: running out of fuel), the hev and engine warning light both illuminated and the 'ready' light was de-illuminated.

- Westminster, CO, USA

problem #4

Mar 182011

Sonata

  • 7,000 miles
Turned into driveway, car slowed to 5 mph. Suddenly car rapidly acelerated and car struck garage door pillar on LH side. Car stopped by impact. Extensive damage to garage structure. Car has extensive damage to left fender, head light, bumper and hood. May have hidden damages.

- Burnsville, MN, USA

problem #3

Feb 222011

Sonata

  • 10,500 miles
I drove to the local tom thumb store and was pulling into a parking space. My foot was on the brake and the car was almost to a complete stop when it suddenly lurched forward and the engine spontaneously went to full throttle. I mashed down on the brake peddle as the car jumped the curbed and crashed through the store front. The engine continued to race until I switched off the key. Skid marks were evident on the pavement where the brakes tried to hold the car with the engine racing. The Florida highway patrol investigator did not issue a citation stating that there "was an obvious vehicle malfunction".

- Pensacola, FL, USA

problem #2

Jan 052011

Sonata

  • 800 miles
When starting from a stop, the vehicle would accelerate for a very few feet - maybe 6-8 feet, and then quit - like the engine had died, but it hadn't. this has happened 4-5 times and 3 of these times were when turning left through an intersection with on-coming traffic. The last time was especially harrowing because it was during rush hour traffic. It seems to take 3-5 seconds for the engine to "catch" and accelerate on through the intersection. Pumping the accelerator peddle did not help. It is like the engine is receiving no fuel, or it is flooding out from too much fuel (no smell of gasoline was detected, however). This is a potentially dangerous situation if the engine ever fails to "recover" and accelerate as it should. It should also be noted that I have complained to my dealer that this car does not run from idle as other cars of the same make I test drove - it is somewhat hesitant all the time - sluggish.

- Los Lunas, NM, USA

problem #1

Mar 162010

Sonata

  • miles
2011 Hyundai Sonata: I had heard about the door latch recall on my new Sonata via news reports. I purchased this Sonata on Feb 16th,2010. So, I called and the dealer(St.augustine Hyundai)said I wasn't included in the door latch recall. The dealer said there was 2 bulletins on my Sonata anyhow. #1, the ignition wire needs rerouting or it could become afraid. #2, the ECM computer needed re-programming at that time with an explanation that some new software from Hyundai when it arrived to the dealer, they would check the parameters of the ECM computer program. Now, I haven't to this date received any information regarding any of these 3 issues with my new 2011 Sonata from anyone in the mail" on 3/16/2010 yesterday I received a call from Hyundai usa corporation. The man said my car" is" affected now by the door latch recall. I didn't ask him about the other 2 bulletins mentioned by the dealer nor did he mention them to me. He said I would receive a letter about the door latch recall soon. But nothing again about the other 2 issues" I have been on hold for 45 mins once today and 35 mins yesterday and just hung up because its been too difficult getting anyone at Hyundai, the press(or speak) recall option to route ones call on phone or dept said its having high call volume due to recent recalls.I called St.augustine Hyundai back yesterday and spoke to service manager and he said it's showing now about the door latch and the other 2 issues still exist like he told be weeks back already on the phone. I asked what needs reprogrammed with the ECM computer. He asked me to hold, came back and said if that isn't tended too. The engine could stall or the car might suddenly be able to go no faster then 20mph. This sounds unsafe and I haven't received any letter official from Hyundai corporation. If I'm driving and my car stalls or I'm on the freeway and the car drops from 70mph to 20mph without my desire to do so is unsafe?they supposedly spent 4 years developing the vehicle.

- New Smyrna Beach, FL, USA

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