Table 1 shows one common engine and engine cooling related problems of the 2021 Hyundai Elantra.
| Problem Category | Number of Problems |
|---|---|
| Engine And Engine Cooling problems |
The contact owns a 2021 Hyundai Elantra. The contact stated that there was a knocking sound coming from the engine compartment while the vehicle was idling. The rpm fluctuated and the vehicle stalled while at a complete stop, and while shifted to park(p). The contact restarted the vehicle and was able to continue driving. The check engine warning light was illuminated. The failure had occurred intermittently. The vehicle was taken to the dealer, who confirmed that the 2. 0l engine was known for similar issues. The dealer confirmed that the VIN was not included in NHTSA campaign number: 21v301000 (engine). The vehicle was not diagnosed due to a lack of diagnostic trouble codes being displayed. The vehicle was not repaired. The manufacturer was informed of the failure, and a case was opened. The failure mileage was approximately 127,000.
Heating core on car has gone out 3 times the first time costing $2,042. 03 to repair, the two follow up ones were done under the warenty.
Constant sound of flowing water throughout the front of the vehicle. Several service appointments later and there is still no solution to the issue that has been going on for over a year. Thia can be heard like a stream of water flowing. Engine ticking, loud rattling from engine. You can hear in from inside of the car.
This is my second time contact and reporting this issue about the vehicle surging unexpectedly and you cannot get it to slow down except by keeping your foot on the brake and pulling off the road. This has happened multiple times since I have had this vehicle. Recently, I had the car in for service and they said they did a recall for the software to stop this condition from happening again. However, 1 month later, it happened and this time it was the worst I have ever experienced as I kept my foot off the accelerator - it surged over 15mph from the speed I was originally at with me doing nothing and it was still gaining. My car was trying to accelerate with my foot on the brake and I had to cross lanes of traffic to get to the side of the road to restart the vehicle. The reason that it was the worst, is that I literally could not begin to control this vehicle. Other times it has happened and I could at least go for a little bit as long as I kept my distance from other cars but this acceleration was beyond out of control. I could have caused an accident or hit somebody. No warnings appeared, no messages or lights.
Engine shots off while on the automatic stop and go idle . It is being doing it for a while but it is happening more often even with the auto idle off and it even happened at the freeway. It gives me a message to put it in park or neutral and turn the engine on manually. Making this a very dangerous situation because cars behind me don’t know that my engine suddenly shots off. Thanks.
The h e v warning light comes on when driving. The hybrid battery disconnects from the engine and the car is undriveable. Have to pull over, stop the car, turn off the car and then reset the hybrid battery. This has happened twice in last week. Thank fully I was able to pull over safely, but this a dangerous situation for me and other cars around me. The car had been taken to the dealership just two weeks ago and they were unable to diagnose the issue.
I am writing to report a serious and ongoing safety issue with my 2021 Hyundai Elantra hybrid that remains unresolved despite multiple visits to Hyundai service centers and independent repair shops. I’ve also found numerous consumer discussions online describing nearly identical issues with the same model and newer Elantra hybrid models, suggesting this may be part of a wider systemic defect. The core issue lies within the vehicle’s hybrid system. Shortly after a recent system/software update performed at a Hyundai dealership, a warning message began appearing at random intervals stating: “check hybrid system. ” this typically first appears after extended driving — often around 3 hours — but once it occurs, the issue worsens if I continue to drive. Each time the warning appears, the vehicle suddenly and drastically decelerates without driver input, becoming dangerously slow and unresponsive, even while traveling at highway speeds. This creates an urgent safety risk, as I have had to maneuver off the road quickly to avoid collisions. After the initial warning, if I attempt to drive the vehicle again without sufficient downtime, the warning reappears much more frequently — sometimes within minutes. The only temporary relief is to stop using the vehicle and allow it to rest for at least six hours, after which the issue may temporarily subside. In every case, I must use the 12v battery reset button to restart the car, which I suspect may be clearing diagnostic codes before they can be properly recorded. Notably, the check engine light disappears after this reset, even if it was previously displayed. Given that the hybrid battery is located beneath the rear passenger seat, I am deeply concerned that if there is an underlying thermal or electrical issue, it could pose a serious or life-threatening risk to passengers. To date, no dealership or technician has been able to duplicate or permanently resolve the problem.
So the car will come to a dead stop. Then when I give gas, it will not go for 1-2 sec, then all of a sudden it go at high speed by itself. Even when I brake, it will feel like as if I have stepped onto gas. Very dangerous.
Car will accelerate when pressing on brakes. Once car is able to turn off, the problem does not repeat. This has occurred at least 3 times with the same car and random times while on the road. Dealership is unable to replicate the brake issue every time the car is brought in.
The contact owns a 2021 Hyundai Elantra. The contact stated that while driving at an undisclosed speed, the vehicle overheated. The vehicle was taken to the dealer, who informed the contact there was a crack on the radiator. Additionally, the dealer determined that the failure was possibly collision related; however, the contact stated that the vehicle was not involved in a collision. The manufacturer was not made aware of the failure. The failure mileage was 39,573.
I completed an oil change at greggs oil express in porterville California on 02-11-2023. I have the invoice. On 02-24-2023, I went out of town. At approximately, 5:00 pm, I heard a loud bang, large amount of oil pouring out of the bottom of the car, the car became disabled and I pulled over to the side of the road. I had it towed to the closest Hyundai dealership in victorville CA. They provided me with a report that stated when receiving my oil change stating due to the drain plug issue is a direct result of a third party and was not covered under warranty. I then made contact with my insurance, an investigator also reported the same. I have both reports. I have made contact with greggs express where I received the oil change and it was suggested to report the incident as they have come across situations like this with the particular vehicle. Therefore, I am now stuck. It is not covered under warranty, not covered under insurance, and the cost is 10,000. Besides the fact that I could have been injured.
Our problem started a few months ago. At first, we thought it was just a fluke, but this issue has happened too many times to be so. The issues are, the car does not accelerate when we depress the accelerator, we see the tachometer move, but the engine is not actually accelerating. Then at times it will accelerate on it's own, while sitting at a red light, the car tries to move forward despite having our foot on the brake, it acts like we are trying to push the accelerator and the brake at the same time. Even worse, while driving, the car will go into accident-avoidance mode, even though there is nothing in front of us. There are no errors or codes populating on the dash.
I picked up my Hyundai Elantra n-line today 12/1/22. My car was at the dealership for almost 3 weeks for transmission judder (shudder?) issues and they claim to have fixed the issue with a TSB (technical service bulletin) from Hyundai with some snap and cable and additional work that was not disclosed. After picking it up and driving only 3 blocks my car went berserk where all dummy lights went on, the car's engine revved to redline, took off and suddenly the front wheels turned left (due to the avoidance features of the car perhaps) and I was able to pull the emergency break and stop the car. The car stopped luckily and if the e-brake did not work I would have ended up hitting the rear corner of a car and into a house. While the car was stopped, it was still on (unable to be turned off), all lights blinking including dummy lights and the car was showing still in drive mode even though the revving stopped and the car was dead stop. After 10 minutes I was able to turn the car off (push button). Dealership dispatched a tow truck and now my car is back at the dealership for investigation. Note: TSB is something that is a known issue from Hyundai but not yet to the level of an official recall is what I was told by the dealership.
The contact owns a 2021 Hyundai Elantra. The contact stated that the dealer had previously performed an unknown recall repair as well as an oil change; however, the failure occurred after the services were performed. The contact stated that while driving at an undisclosed speed, there was smoke coming from the exhaust pipe with the engine oil warning light illuminated. The engine oil had leaked onto the roadway while driving. Upon inspection, the contact noticed that the engine oil drain plug was missing. The dealer was made aware of the failure but provided no assistance. The vehicle was then taken to columbia Hyundai (10981 montgomery rd, cincinnati, OH 45249) however, the vehicle was not yet diagnosed nor repaired and remained at the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 15,500.
On multiple drives the car has "lurched" or accelerated when foot was not on the accelerator pedal. These were minor issues, but unnerving when pulling up to park near a structure. Today 3-23-22 I was driving and after about 1 hour of normal operation the car began to accelerate while pressing the brake, and decelerate while pushing the gas. The engine was revving and then slowing down opposite of what would be expected. This is a hybrid vehicle - it felt as if the gas engine was supposed to be spooling up to charge the battery but instead was feeding power to the wheels. There was no engine light illumination from this. I restarted the car and it seemed ok. Honestly, this was scary - trying to move from one lane to the next to an exit to safely exit the morning rush hour freeway. I had to keep my foot heavy on the break to make it slow / stop. On two other previous drives the vehicle "lurched" / the car "bucked" once or twice and then the gas engine would not re-engage. The mil came on, and the car drove on battery power only. I drove off the road, restarted, and the vehicle worked fine. By the time I got the car to the dealer the mil had cleared and they were unable to pull any codes and deemed the car safe / found no issues.
On 1/27/2022 my daughter was driving home from school in her 2021 Hyundai Elantra sel which was purchased new on 6/19/ 2021 when at 5600 miles on the odometer a message came on the instrument cluster which read put car in neutral and turn off engine, when it was safe to do so she stopped the car and turned it off in the middle of a two way road because there was no shoulder and no place to exit the roadway when she tried to restart the car the engine would not crank or turn over to start the car so she called me and I called a tow truck while she was waiting vehicles behind her where forced to go around her car when it was safe for them to do so, the tow truck came and took her car to the dealership where she purchased it two days later they called and informed us the engine was completely seized up and that they would have to replace it with a new engine despite the fact the original engine had oil and was only six months old with only 5600 miles on it.
At about 11 months old my car suddenly seized while attempting to enter the highway. This came with no type of warning from the vehicle until the car had stopped and then every light on the cluster came on. I was fortunate not to be rear ended. The car was towed and 2 days later the dealership called to tell me there were no errors and nothing was wrong with the car. I told them what had happened and they called later that day and I was informed that they needed to install and entire new engine assembly. The car only had 7000 miles on it and should not need a new engine. There is some major design flaw with this car which poses a safety issue. Additionally I looked at my service records for the car and it looks as if the dealership is trying to cover up the fact that a new engine was placed in the vehicle as it is listed as routine maintenance. Please look into this and contact me if needed.
The contact owns a 2021 Hyundai Elantra. The contact stated while driving at 40 mph, the vehicle shut off. The message "put car in neutral and restart engine" was displayed. The contact stated that she shifted into neutral (n) and restarted the vehicle; however, the failure reoccurred persistently. The vehicle was towed to the dealer where it was diagnosed that an unknown activator needed to be replaced. The part was replaced. However, the contact stated that days after the repair, the vehicle would not exceed 25 mph while driving. The contact pulled into a parking lot. The contact stated that a police officer was able to assist her with correcting the issue under the supervision of the dealer who was on the phone. The contact resumed driving and the vehicle responded as needed. The manufacturer was notified of the failure. The failure mileage was unknown. The contact later received recall notification of NHTSA campaign number: 22v354000 (seat belts), however, the parts to do the recall repair were not yet available. The local dealer was not contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time to complete the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.