2015 Kia Optima: engine knocking or ticking

Filed Nov 4, 2026 · Engine · WA

I was driving to work when all of the sudden I was pressing my gas, but I wasn't accelerating. I noticed my brakes and steering wheel were hard to push and turn. My car stopped in the middle of the road. I turned off my car and tried to turn the ignition and all I got was a single click. My engine, battery and oil lights were now on. They were not before. After 25 minutes in the middle of the road a sheriff came and pushed me to the side. When I put my car in neutral it was hard to steer and my brakes were hard to push. I was terrified that I was not going to be able to stop. I was scared I was going to be hit and someone would get seriously injured. I then received a call from Cascade Automotive saying that my engine seized from rod bearing failure but my engine was under warranty under the Kia Engine Class Settlement. I called Kia Consumer service and they said my Vin# qualified and was under warranty. I then had it towed to Kia of Puyallup. They confirmed it was a Rod Bearing failure that caused the seizure and told me it did qualify for the warranty. But then told me since I didn't get the HECU fuse update its void. I told them I never got a notice for the recall. They said it didn't matter and said to fix it, it would be $6700. I called Kia Consumer again and asked what can be done and they said nothing. I asked if they had any record of sending me or my dad ([XXX]) the recall notice and they said no and he wasn't in their records as the registered owner. I then asked since they have no record of sending the recall notice to me or my dad and I had no way of knowing about the HECU fuse if the warranty is good now and they said no, I should have looked for recall. There were no warning signs. I have maintained my car and had the oil changed regularly. My safety was put in jeopardy because Kia failed to notify me of a faulty engine and the HECU fuse. I asked for the records saying no notice was given and they said it was against their policy to send that. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORM

Filed Oct 23, 2026 · Engine · NC

There is a known issue with this vehicle and the fix by KIA is not safe nor fair to the consumer. Kia's knock sensor recall centers on the Knock Sensor Detection System (KSDS) software update for Theta II GDI engines. The update listens for rod bearing wear, triggers a check engine light and limp mode via Code P1326, and extends the engine warranty up to a lifetime or 15 years/150,000 miles. My problem is that we had to car in on May of 2026 after in went into limp mode. They updated the software. The car again went into limp mode on 10/21/2026, they updated the software again. My focus here is the fact that it is a known issue and they say it still does not meet the parameters for an engine replacement. It is a severe issue that is dangerous and inconvenient to the driver. You are afraid to take it on a trip or even take it on a highway. My 20 year old daughter drives this to college. Can you imagine a car going into limp mode on a majory US highway? Limp mode essentially does not allow a vehicle to go above 2K RPM. You cant go up a hill over 35 and on a highway, on a flat road you "might" be able to go 55 MPH. My daughter goes to college 4 hours away. This creates a very unsafe, dangerous and inconvenient environment. KIA is hoping that they can buy time until these vehicles fail for some other reason and they dont have to pay the cost for a new engine.... ALL at the consumers peril. To put this in perspective, if you have a vehicle with a "low tire pressure" warning, does lowering the sensors parameters fix the problem.... No, it just turns off the warning and you are driving a car with low tire pressure.

Filed Sep 20, 2026 · Acceleration, Engine · KY

My energy in my car started messing up with only 150,000 miles it had a long knocking sound and it would not got over 20 miles while driving

Filed Aug 13, 2026 · Engine, Fuel system · MA

This is a formal vehicle safety complaint regarding a manufacturer's active refusal to remedy a known safety defect under an active recall campaign guidelines.My 2015 Kia Optima Turbo experienced an active internal mechanical engine knock, violent sputtering, and a complete engine seizure. The vehicle is currently sitting un-driveable at an authorized Kia dealership.The required Knock Sensor Detection System (KSDS) software update was successfully completed on this vehicle prior to the incident, legally qualifying it for a 100% free long-block engine replacement under the manufacturer's active Lifetime Warranty extension. However, the dealership service department is actively withholding the safety warranty paperwork and refusing to submit the diagnostic photos and engine seizure data to corporate for warranty approval unless I agree to pay an additional $800 out of pocket for an external throttle body and O2 sensor.I have explicitly declined the retail accessory charges five separate times. I only authorize the replacement of my front sway bar links. Instead of separating the ticket and processing the free engine block safety remedy, the dealer is holding my safety warranty hostage to force a retail sale. Furthermore, a manufacturer consumer care representative recently refused to listen to my request on this matter and dropped the call.The manufacturer is using internal technical advice to block a court-ordered safety remedy and is allowing a dealership to use unauthorized retail accessory charges to deny me a safe, operating vehicle. I request immediate federal intervention to force the manufacturer to release the free engine block safety replacement order to the dealer and halt these predatory dealer practices.

Filed Jun 23, 2026 · Engine · OK

While driving my 2015 Kia Optima, the engine failed completely without warning. The vehicle lost power while in motion approximately 300 miles away from my home. All warning lights illuminated and the car shut down during driving conditions, creating a serious safety hazard. The vehicle was towed to a Kia dealership where it was inspected. I was informed the engine has failed and may be related to the known 2.4L engine defect and prior recall campaign involving this engine type. This vehicle has a history of multiple recalls, including engine-related recalls issued in 2018 for the same engine family. The failure occurred suddenly and without prior adequate warning, and the vehicle is now inoperable. I purchased the vehicle in May 2023, and at the time of failure it had approximately 133,000 miles. The engine began knocking loudly prior to failure, then stalled and shut off completely while driving. This incident placed me and others at risk because the vehicle lost propulsion while in traffic. I believe this may be related to a known manufacturing defect in Kia 2.4L engines that has been the subject of recall and/or investigation. I am requesting that this complaint be documented as a safety-related engine failure potentially associated with the existing recall and that it be reviewed for further investigation and manufacturer accountability

Filed Jun 8, 2026 · Engine, Transmission · AZ

P1326 code flashing engine light knock sensor went out 3 times in 6 months and just replaced it again and this time engine light didn't go off I was reading that there was a recall on this but apparently mine doesn't state it. Car cannot pass emissions if engine light is on and the 15th of June is approaching. The car doesn't make any sounds or nothing.

Filed Feb 24, 2026 · Engine · FL

The vehicle started making a loud knocking/tapping noise while driving. The vehicle has randomly acted as if it was going to stall while driving prior to the knocking. Instantly the car was brought home and parked. A mechanic has assessed the vehicle and states the noise we are hearing is the rods. We also contacted another mechanic and they advised us to look up the VIN due to a recall for 2015 Kia optima’s and the failure of this exact issue but we learned it was only for hybrid models even though this model has had the same exact issues as that model. I then see there have already been complaints made for my same issue and model yet no recall campaign has been initiated. I am fearful to drive or try to sell this vehicle because what if someone else drives it and it does stall again during driving and injury or death occurs.

Filed Feb 13, 2026 · Engine, Transmission · CA

On December 27, 2025, at approximately 150,556 miles, my 2015 Kia Optima Hybrid experienced sudden engine knocking, power loss, and failure while driving at 65 mph on a highway. The vehicle dropped into limp mode and I had to pull off the highway. The car required towing to the dealership as it would not drive safely. Diagnostics revealed a knock sensor error (P1326 code) and failing connecting rod bearings via Bearing Clearance Test, consistent with the known Theta II engine defect (manufacturing debris causing oil starvation and premature bearing wear). This follows earlier symptoms: Intermittent 'Check Hybrid System' warnings in early December 2025 at 148,665 miles (dealership unable to reproduce, but historical codes noted). The Knock Sensor Detection System (KSDS) software update was performed in February 2022 during prior CHS warnings. Despite onset of issues under the 150,000-mile extended warranty limit per the Kia E2 Settlement, Kia denied coverage due to the minor mileage overage and directed me in a loop between Consumer Assistance and the Settlement Administrator. The defect poses a serious safety risk: potential for sudden engine seizure, stalling while driving, or engine compartment fire (as seen in related Theta II recalls and thousands of the federal safety agency complaints). No crash, injury, or fire occurred in my case, but the failure left the vehicle undrivable and unsafe on the road. I have service records and diagnostic reports to support this.

Filed Dec 16, 2025 · Engine · TX

The engine in my 2015 Kia Optima suddenly seized due to connecting rod bearing failure at approximately 55,000 miles. This vehicle is known to be affected by the Theta II engine defect. I was never aware of the seriousness of the recall software update and did not receive meaningful notice that failure to install it could result in catastrophic engine failure. Kia has denied engine warranty coverage solely because the software update was not installed prior to failure, despite the defect existing regardless of software.

Filed Dec 15, 2025 · Engine · CA

My 2015 Kia Optima (VIN [XXX] ) experienced sudden engine failure and stalled while driving at approximately 90,000 miles. There was no oil pressure warning light and no knocking prior to failure. The check engine light illuminated shortly before the stall. Kia is denying engine coverage solely because an ECU/KSDS update was not performed. I was never notified of this update because Kia had an incorrect address on file for me. This failure is consistent with known Theta II connecting rod bearing defects that have resulted in recalls and warranty extensions. I believe this is a safety-related defect and am requesting review. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Dec 3, 2025 · Electrical, Engine · FL

The incident took place on Sunday, December 30th. I was driving to pick up my children from their father and on our way home my car stopped accelerating entirely. This had only happen one other time a few days prior. I was in a gas station parking lot and initially when I turned my car on and went to put it into drive it wouldn’t accelerate. I thought that was odd so I did the only thing I knew how to, I checked my oil levels. Levels were full and no other issues were there. The check engine light had popped up when I turned my car back on but my car did accelerate so I thought nothing of it. I took my car to auto zone for a diagnostic and they told me my “B cam shaft” sensor needed to be moved and that could be causing the engine light to come on and ticking in my motor. I called a few shops getting quotes and eventually was forced to tow to the closest shop to me after my car refused to start overall. They replaced the battery and the b cam shaft censors and still were unable to get the car started. They told me 3 recalls were open on my car, including the motor and to have it towed to Kia for a full replacement. After calling Kia to have the repairs done, they refused me service based on a previous owner not handling prior recalls.

Filed Dec 3, 2025 · Brakes, Engine · 77,000 miles · UT

The contact owns a 2015 Kia Optima. The contact stated that while driving at 40 MPH, there was an abnormal knocking sound coming from the engine. No warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed with engine failure, and the contact was informed that the engine needed to be replaced. The contact stated that the dealer refused to repair the vehicle. The contact was informed that the HECU recall repair needed to be completed first. The contact was unaware that the vehicle was included in the federal safety agency Campaign Number: 21V331000 (SERVICE BRAKES, HYDRAULIC). The vehicle remained at the dealer unrepaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 77,000.