2017 Hyundai Elantra GT engine problems

“The Engine stalled completely at highway speeds. It was then towed to the dealership and was diagnosed with engine rod bearing failure. Hyundai is denying the warranty extension for this engine failure based on an incomplete 'Service Campaign 966' that does not appear on the NHTSA public recall database, leaving consumers unnotified of safety-critical software updates."”

“My vehicle was brought to an authorized Hyundai dealership In November 2025 to complete safety recall campaign KSDS (Campaign 966). Soon after picking up the vehicle after the dealer flashed the ECU, the vehicle went into a permanent, dangerous "limp mode" that severely limits the engine's RPMs, making it impossible to accelerate to highway speeds. The vehicle's computer displays zero OBD-II diagnostic trouble codes (no P1326 or standard fault codes). The dealership is refusing to address this issue, falsely claiming a plugged catalytic converter, despite the vehicle having passed a strict California Smog Check with perfect emissions and zero catalyst codes, just a few weeks before the update was performed, and ran perfectly normal. This recall software update has rendered my vehicle extremely unsafe to drive on public roads, and the manufacturer's authorized repair facility is refusing to remedy the electronic damage caused by the recall installation. I am trapped driving a disabled vehicle in a permanent, dangerous software loop.”

“I am writing to formally log a critical safety and product reliability complaint regarding my Hyundai Elantra GT. The vehicle has suffered catastrophic engine failure characterized by severe rod knock. This failure occurred without any prior warning from the vehicle’s onboard diagnostic systems, exposing an engineering and sensor flaw that creates an immediate safety hazard.The vehicle was operating normally when it suddenly developed a distinct, heavy metallic knocking sound from the engine block, indicative of failed connecting rod bearings. Upon immediate inspection, the issue was linked to critical oil starvation or pressure drops.Crucially, the vehicle’s warning systems failed entirely to alert me to an issue:No Low Oil Pressure Warning: The dashboard oil pressure light never illuminated to warn of low pressure or critical oil level depletion.No Check Engine Light (CEL): The engine sensors failed to detect underlying mechanical distress, oil degradation, or early-stage misfires before the catastrophic failure occurred.Complete System Silence: The vehicle gave absolutely no visual or audible alerts on the instrument cluster, depriving me of the chance to…”

“After a Hyundai dealership installed the Knock Sensor Detection System (KSDS) update to prevent engine bearing failure and potential fires in certain Theta II, Nu, and Gamma engines, my Elantra GT is stuck in limp mode and will no longer accelerate. Since it takes my car a very long time to reach safe driving speeds, I took the car back to the dealership and they conveniently blamed the catalytic converter. I went for a ride with a California BAR associate, and he agreed that the update was causing my engine to go into limp mode, and it wasn't a symptom of a plugged CAT, but he was unable or unwilling to help me. Hyundai acknowledged that the engine does qualify for the Theta II extended warranty but will not explore that possibility until I have them replace the cat for $3,300, which we both know isn't going to solve anything. I have contacted Hyundai Corporate Customer Relations, and even the BBB, who refuses to qualify my car for their Engine Replacement class action lawsuit because the engine hasn't seized up yet, which will never happen since the update is preventing it. Even lemon law lawyers refuse to assist me because the car is too old. Since this is…”

“I was told by the mechanic about the following. My car has shown engine oil burning issue, and it made the timing chain placing in the faulty function frequently. I changed the timing chain last year and was advised that I would need to check engine oil level because of engine oil burning issue. I was advised to check it at every 2500 miles. Recently my car showed check engine light on again, so I visited the repair shop and found out that the engine oil was totally gone before 2000 miles. The synthetic engine oil change should be at every 5000 miles. The rapid engine oil consumption made my car getting check engine sign on and I was told that it eventually would stop my car. And I was told that it is very hard to fix it because it is due to faulty engine issue.”

“The contact owns a 2017 Hyundai Elantra. The contact stated that after starting the vehicle, the vehicle lost automotive power and then lost power after driving a short distance. No warning light was illuminated. In addition, there was an abnormal sound coming from the engine. The vehicle was taken to a local independent mechanic; however, the failure was not replicated. The contact stated that the vehicle was previously taken to the same independent mechanic, and the spark plugs were replaced. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 150,000.”