2017 Hyundai Elantra: misfire or rough idle

Filed Jun 29, 2026 · Electrical, Engine · CA

While operating my 2017 Hyundai Elantra under normal driving conditions at approximately 70,000 miles, the engine suffered a sudden, catastrophic loss of motive power and stalled completely while moving in active traffic without any prior warning. This severe stalling event occurred despite the vehicle being strictly and meticulously maintained according to all manufacturer guidelines and scheduled service intervals. Prior to the stall, the Check Engine Light illuminated. A comprehensive diagnostic scan completed at an authorized Hyundai dealership confirmed active trouble codes P0014 (Exhaust Camshaft Position Timing Over-Advanced) and P0017 (Crankshaft-Camshaft Position Correlation Error). The internal physical engine timing assembly and Variable Valve Timing (VVT) components slipped out of synchronization, forcing an abrupt, automatic engine shutdown while navigating active roadways. This failure created an immediate, severe safety hazard and high collision risk due to the sudden loss of vehicle propulsion, power steering assist, and vacuum brake booster pressure, leaving me vulnerable in traffic. This structural timing deviation caused chronic engine misfires and forced raw, unburned fuel directly into the exhaust stream. This unburned fuel completely fouled and destroyed the primary Oxygen (O2) Sensor due to heavy carbon contamination and extreme thermal stress. The failed sensor and incorrect valve timing totally disrupted the electronic control unit's air-fuel management, inducing the unpredictable stalling hazard and causing an immediate, automatic state emissions/smog inspection failure. Repairing this underlying manufacturing and metallurgical defect at the official Hyundai dealership required an extensive mechanical teardown and replacement of the timing components, costing approximately $2,500 out of pocket. This exact failure pattern, cascading O2 sensor damage, and diagnostic trouble codes match hundreds of existing complaints with the federal safety agency.

Filed May 22, 2026 · Transmission · NE

What component or system failed or malfunctioned, and is it available for inspection upon request? How was your safety or the safety of others put at risk? The ignition coil in my 2017 Hyundai Elantra Limited has failed multiple times over the past several years. This recurring issue has caused the vehicle to malfunction unexpectedly, creating safety concerns due to reduced engine performance, misfiring, and the potential for sudden loss of power while driving, which puts both myself and others on the road at risk. The failed component is available for inspection upon request. Has the problem been reproduced or confirmed by a dealer or independent service center? This issue has occurred multiple times with my vehicle. After researching online consumer reports and owner complaints, I found that ignition coil failures appear to be a common and recurring issue reported by other 2017 Hyundai Elantra Limited owners. Based on these repeated failures and similar reports, this appears to be a known issue affecting this model. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others? I have reported this issue to Hyundai multiple times. Rather than addressing the root cause or issuing a recall for this recurring defect, Hyundai has repeatedly provided credits to assist with repair costs when the ignition coil fails. Despite the repeated failures and safety concerns, the underlying issue has not been permanently resolved. Were there any warning lamps, messages, or other symptoms of the problem prior to the failure, and when did they first appear? Prior to failure, the vehicle would experience rough starts, engine misfires, and poor performance. After these symptoms began, the check engine light would eventually illuminate. Once the warning light appeared, the vehicle became increasingly unreliable and would stall or shut off unexpectedly. On one occasion, the vehicle shut off completely while I was driving.

Filed May 19, 2025 · TX

Coil 1 & 4 misfire. Won’t accelerate well & engine light blinks. Car will stall then die when engine light blinks too much in 1 minute.

Filed May 7, 2025 · Engine, Transmission · VA

My car has been stalling and shaking for months on acceleration. This has put me in unsafe situations where vehicles are going very fast on the highway and I am going 20 miles under the speed limit, or I am accelerating to merge and my car fails to accelerate, or I'm on the regular road and my car slows to a crawl while people are coming in fast behind me. The Error Code is: Cylinder 3 misfire. Took it to the dealer, they said they couldn't find anything wrong with it because the light was not on, they updated the software, as soon as I drove home the problem came back. They still charged me $200 for service, even thought the vehicle is under powertrain warranty which covers the cylinder block head and all internal parts. Online research shows this is a common problem in 2017 Hyundai Elantras. Many tried replacing coils and spark plugs only for the problem to return again a few months later. One successful fix found the computer needed to be replaced with a new one.

Filed May 7, 2025 · Electrical · ID

Constant misfire issue causes vehicle fo completely bog down while driving..

Filed Mar 29, 2025 · Engine · NJ

Engine light keeps coming on... took back to dealer twice coil misfiring had to be replaced Car was bought in 2018 Coils were replaced twice in 2020 because of check engine light and car not running In 2024 coils had to be replaced again because of engine failure 2025 blinking check engine light on again engine failed needs to be replaced Maxon Hyundai refused to replace the engine.,. Car has 86,000 miles Does not meet the 100000 threshold

Filed Dec 5, 2024 · Engine · CO

Ignition coil failure. Causing misfires and rough idle. Misfire initially found in cylinder 2 when check engine light illuminated and check with an OBD II reader. Swapped the cylinder 1 ignition coil with cylinder 2. Check engine light returned the next day with the same signs. Check engine light and rough idle. OND II code scanner now says misfire in cylinder 1. The rough idle makes for slow acceleration until above 20mph.

Filed Feb 20, 2024 · Engine · TX

The Issue started back in December of 2023.The Engine failed while driving to Lake Worth, TX. Vehicle Information: Model is a 2017 Hyundai Elantra Limited 2.0 Engine, US Built. Mileage during the1st incident was at 100,125 miles and the VIN Number is [XXX] . I was on a Maintenance plan the first 2 years with Clay Cooley Hyundai of Dallas with Dealership Warranty when I first purchased the vehicle back in 2017 so I kept up maint.Stalling began & was making a significant tapping noise.Dgnstcs were performed and I initially got Misfire codes P0303, P0300 &P0301. Ignition coils and sprk plugs were observed and replaced. Instantly following I ran another diagnostic and began receiving Camshaft codes P011.The VVT Solenoids were also replaced and this still did not resolve the issue. I was losing oil after every oil change and the oil was not lubricating the engine. I then took to a local shop and they said engine was beyond repair and had it towed to dealership. loud knocking noise from the engine that increases in frequency as the engine rpm increases. Then there is Reduced power and/or hesitation and vibration. With these issues the Illumination of the “check engine and Engine Oil Pressure” light come on in the instrument cluster. Safety Concerns: Stalling and Shutting off of the engine while driving at accelerated speeds is a Dangerous Manufacturing issue that could have resulted in a major car crash not only jeopardizing our safety but the safety of other drivers. Similar Incidents: There have been several reports and forums that we have read that report the same issues with their Elantras. Impact on You: This has impacted me Tremendously as the Dealership states that they cannot assist with the Damages and that I would have to come of pocket by paying over $8,000 to replace the engine. Financially this is beyond my means in what I can afford and stalls my primary source of transportation for commuting back and forth to work, taking care of day to day priorities. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFO

Filed Jun 13, 2023 · Acceleration, Engine · NJ

Since buying my vehicle new, it has had three ignition coils fail at different times. The car begins to shudder, rough idle, not accelerate and all of a sudden just will not respond to giving it gas. This happens at any speed therefore it is a danger especially entering or exiting highways or switching lanes. It has been unpredictable. The check engine light does come on some of the time as this problem is occurring, not before. The dealer replaced the first two coils (51, 576 miles and 56, 446 miles) under the warranty. The third coil replaced (78, 391 miles), they would not cover under warranty, nor would they replace the 4th coil as a precaution.

Filed May 28, 2023 · Engine · CO

Car shaking when accelerating. Check engine light. Misfire code. Earliest appointment with dealership is Thursday June 1st. At 2 pm on Saturday May 27th check engine light went off.

Filed May 22, 2023 · Brakes, Engine · CO

Have had the vehicle throw a code for a misfire 4 times in the 30,000 miles I have driven it. The times I have taken it to Hyundai dealerships in Northglenn and Boulder, Colorado they tried an update and just swap ignition coils to different cylinders. Example misfire is cylinder 3. They swap number 3 and 4 ignition coils to see if they can recreate the problem I the new cylinder. There is already a TCS 20-FL-001h. I recommend a full recall of these defective ignition coils be put out as the problems are still occurring. The problem is reoccurring and the time it takes to get into the shop is 3 weeks out at this time. By the time I get it in the code usually resolves and I have to wait until I get violent shakes and poor acceleration to indicate it is back. Had an accident in January if 2023 and it seemed the brakes were t working as they should. Twice after that the brakes felt as if they weren’t stopping as well as they should. I took the vehicle in and had the rear drum brakes adjusted and that seemed to fix the problem.

Filed May 14, 2023 · Engine · VA

Ignition Coil Failure on 2017 Hyundai Elantra with just over 29,000 miles. Engine misfiring, jerking, idling roughly, and hesitating while accelerating, along with the Check Engine Light turning on. On-board diagnostic tool generated a P0-301 Diagnostic Trouble Code - indicating that cylinder number 1 experiencing misfires. Took my car to dealer for repair. Ignition coil and software updated pursuant to Hyundai TSB # 20-FL-001H. Cost $321.46. Hyundai would not pay for all/part of the repair because car is beyond the 5 year/60,000 mile warranty, despite this being a safety issue they acknowledged by issuing the TSB to address the replacement of the defective ignition coils. Hyundai previously issued safety recall on 2106 Sonata models related to a similar defective ignition coil issue. See Hyundai TSB # 16-01-003-1. Ignition coils are expected to last at least 100,000 miles. The premature failure of this part, as evidenced by the 2016 recall, and the 2020 TSB, poses an unreasonable safety risk to the public. Imagine the safety issues while traveling on a roadway with your car misfiring, jerking, or lacking power when accelerating, or stalling.