2016 Kia Optima Electrical System Problems

My rear passenger side window would not go up or down & the motor would run when the button was pressed. That was in January 2026. Now April 2026, my driver's side rear window will not go up or down.

Vehicle: 2016 Kia Optima LX Turbo – Approx. 114,155 miles** This complaint concerns ongoing systemic defects affecting the electrical, braking, and engine management systems of the referenced vehicle. Despite multiple documented repair attempts, the failures persist, creating continuous and significant safety hazards. The vehicle has experienced repeated electrical system malfunctions, including multiple battery failures (three replacements within one year), sustained low-voltage conditions, and intermittent lighting loss. Notably, the headlights and exterior lighting have shut off unexpectedly during extended highway operation. The brake control system is also compromised. The electronic emergency brake has engaged spontaneously while the vehicle was in motion, causing abrupt deceleration without driver input. Additionally, the vehicle exhibits continuous fuel vapor and engine performance defects. The purge valve has been replaced four times, yet the failure recurs. The vehicle frequently hesitates upon acceleration, exhibits delayed throttle response, and jerks during takeoff, creating hazardous conditions when merging into traffic or crossing intersections. Given the repeated nature of these defects and the lack of resolution through standard repairs, I believe the vehicle may contain inherent design or manufacturing defects affecting the electrical charging system, ECU, fuel vapor management components, and electronic braking controls. I request that NHTSA conduct an investigation into these safety-related defects.

Window regulator assembly failed twice within 20k miles. Attached is the first repair. Dealership only repaired motor but not full assembly and it failed again.

1) Rear passenger window failed a couple months ago. I believe it was regulator, not 100% sure. Cost me a couple hundred to fix. Now, few months later, the driver side rear window has failed. I rarely use the windows so I believe the failing parts are Kia known manufacturing defect. The dealer acknowledged that it’s a known problem with the vehicles like mine and even suggested the other one is going to fail soon. Now it has. If the dealership is aware then it’s likely a Kia flaw. If it’s a know manufacturing flaw, shouldn’t Kia should be fixing them instead of making customers spend upwards of $1k+ to fix both windows? 2) cruise control cuts off or doesn’t set and menus won’t go back to speedometer. While trying to set cruise control, it gets into the menu and won’t go back to the speedometer. Sometimes I have to pull over and stop to get the cruise control to work again. It gets stuck in the menu and can’t see the speedometer. Might get stuck on the trip screen, or the range. This has been happening since about 75k miles. It also doesn’t work with the pedal to set sometimes. Messing with it while driving can be a real hazard and sometimes I need to have cruise control to work. It’s deforming more than just inconvenient

Odometer Fraud. The contact purchased a 2016 Kia Optima. The contact stated that while attempting to register the vehicle, it was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. At the time of purchase, the vehicle mileage was 56,276. and at the time of registration, it was discovered that the mileage was 114,000.

3 of windows do not roll up.

A month in after purchasing the check engine light came on. My car did not want to accelerate, started shaking and having jerking movement while driving on the freeway with my newborn and 3 other children in the car with me. Got stranded 3 hours away from home. Car has been in the shop going on 30 days. Spark plugs changed, coolant thermostat changed and now the engine was reported that it has failed. Still in the shop currently.

Vehicle went into emergency mode while in the highway system completely locked could not drive lost power and was forced to pull over and have vehicle towed, mechanic took a look indicated new alternator was required there for we purchased new alternator and new battery car turned on and same issue happened with in 20 minutes of test driving vehicle, this happened twice and could have cost our life’s! I am extremely disappointed and frustrated I have no means to fix the vehicle we used out saving to finally replace what we though was the issue but I’ve come across many same issues from other parties who experienced the same issue. The vehicle is paid off and we need assistance in fixing this issue it appears the engine or electrical issue at this point but I am scared to get on the road we have tried charging it back on but steering wheels locks up and dies a few minutes after please help

The contact owns a 2016 Kia Optima. The contact stated that while driving in inclement weather on several occasions, all four windows of the vehicle became intermittently inoperable. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was notified of the failure. The failure mileage was approximately 130,000.

The headlights and brake lights have been VERY dim for a while. I've had to replace both headlights and brake lights an excessive amount in the last several years. This year alone since December 2024, I've had to replace my headlights 3 separate times. I do not drive more than 10,000 miles per year, or use my vehicle on roads that would lead me to believe the issue is from road conditions.

All 4 of the window regulator motors blew in my windows at the same time, only about 9 years into the vehicle's life. The little plastic pulleys that move the cables degrade over time and then ruin the rest of the window motor when they break, and since they decided not to make this an easily repairable part it requires the entire window regulator assembly which is half of the door to be replaced, not just this plastic part. I had to replace all 4 of them out of my own money, KIA REFUSED to replace something that is completely 100% their fault and it cost me over $3,500 to repair all four windows that went out pretty much at the same time. It's insane silly that anyone's windows can just break at anytime and be stuck in the down position. I can't just put up trash bags and then not be able to see a thing while I wait to get it fixed if it happens again. I was lucky enough to be in a position to get it looked at quickly, but it is absolutely insane that KIA would refuse to cover such a defect. There is already a class-action lawsuit over this I believe but they haven't even attempted to remedy the situation. Not everyone has time to wait for a lawsuit to settle. There should absolutely be some kind of recall/extended warranty on their windows. My engine blew at 57,400 miles only a few months later which is separate and was replaced but it's just insane that I was promised a car but got a piece of trash that consistently breaks while all I can get is a replacement engine with the same exact problem and no confirmation that the same thing won't just happen again while they continue to use the same defective engine over 10 model years. I want them to fix their issues not slap a band-aid over them and hope for the best. This company has been knowingly selling cars built to end up in a landfill within 10 years and they don't care.

The contact owns a 2016 Kia Optima. The contact stated while starting the vehicle, there was a loud knocking sound coming from the engine, with the check engine, oil, and battery warning lights illuminated. Additionally, the contact noticed that all four windows failed to function properly and failed to roll up. The dealer was contacted; however, the cause of the failure was not yet determined. The vehicle was not repaired. The manufacture was made aware of the failure. The failure mileage was approximately 124,000.

My vehicle has been having engine & electrical issues, I originally took the vehicle to a secondary mechanic after Kia Baltimore stated it would be a couple months before they could diagnose the issue. The secondary mechanic was changed spark plugs, and other fixes but advised the vehicle engine was still shutting down and he believe it was related to the Kia engine recall issues. Thereafter, I had the vehicle towed to Kia Towson on 5/22/23..they have had the vehicle ever since I call daily, leave messages with managers, and essentially pay car insurance and car note, and use ride share services while getting no response about my vehicle. The rental manager at the dealership doesn't return my calls, no one. This is unacceptable.

The front and rear windows come down unexpectedly. The power controls do not control the windows. This is especially dangerous when younger children are riding in the car and can reach their hands out the windows because the windows just come down. I have to manually lift my windows up

The engine almost caught on fire. Windows are all down .

The contact owns a 2016 Kia Optima. The contact stated that while driving at an undisclosed speed, she became aware that the driver's side window was not functioning. After which, all the windows in the vehicle failed to operate as needed. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with all four window regulators. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 70,000.

My Kia Optima randomly stops working while driving. I get a notice that says, "HEV: Check Hybrid System. Stop Vehicle and Turn Off Engine." Also the gas pedal stops working, leaving me to try to coast to safety. The car essentially stops working in the middle of driving, without warning. Once this happened and blew out the spark plug, requiring a new one. Then, a day or two later, the car returns to normal. The Kia dealership could not reproduce the problem, nor could my service center. They say it's fine. I took my car in for previous recalls, and it is currently "up to date." This appears to be the same electrical issue as a recent recall for electrical failure, but the dealership told me the spark plug was fine and that I should change the battery. I did and this still happened. I do not feel safe driving this car, and Kia won't help me find the problem.

We have had two motor replacements in less than 6 months that we have owned this vehicle for the first one started started a knocking noise right after a flashing check engine light both Kia is by us totus will we can't get it in today wouldn't give us a rental and was going to charge us for a diagnostics fee right up front and told us it would still be a few days before they could get it in so we had no choice but to continue driving it not even 2 days later left my fiance on the side of the road wouldn't start wouldn't do nothing engine seized Kia dealer number one put the motor put it back together wrong and then when it seized again in less than 5,000 mi try telling us that they weren't responsible well if we did the engine again give it back to us notice that the ignition coils were not put on properly and orbital down properly You're still an electrical issue and the engines are starting to do the engine is starting to do the same as engine one and two. What I don't understand is why don't Kia just completely recall the entire car and take it off to fucking market and replace the people replace the cars that have that still have people owning them

The body shop later informed me that there is a recall for engine fire recently,but my year/make is not listedin the info obtained online. The car started stalling while driving down the off. Smoke started coming through the vents. I pulled over to the side of the highway. A passerby told me that the car was on fire. Called 911. To note I had just picked the car up from Jim marsh Kia for battery replacement and problems with steering after the car was stolen in July. I had no previous issues with my car other than routine maintenance which I have records for.

Heavy oil consumption , unintended acceleration , car jerks . Back window occasionally won’t roll down .