Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

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really awful
Crashes / Fires:
1 / 0
Injuries / Deaths:
3 / 0
Average Mileage:
21,365 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2012 Kia Optima engine problems

engine problem

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2012 Kia Optima Owner Comments

problem #12

Jul 072015


  • 47,000 miles


When cranking up car engine makes loud noise, then if driving at a normal speed the car slows down on it own, also the dash board lights goes from bright to dim to almost no dash board lights at all, driving

- Fort Pierce, FL, USA

problem #11

Sep 172014

Optima 4-cyl

  • 23,000 miles
I was driving home from gulf shores, al to atlanta, ga. I stopped at a rest area. When I started my car back up there was kind of a buzzing noise as I accelerated, but it would stop once I reached cruising speed. After about 15 miles down the road from the rest area, my gas pedal just stopped working. The car coasted until it lost speed and then just turned off. After I was eventually towed to the nearest Kia dealership, I was told that the engine had died and I would need to have a new one installed.

- Decatur, GA, USA

problem #10

Sep 072014


  • 34,800 miles
Cruise control "cancel" button needs repeated pushing to activate. A single push of the cancel button actually seems to accelerate the car.

- Clayton, NC, USA

problem #9

Jan 072014

Optima 4-cyl

  • 34,000 miles


I noticed on Monday that the car seemed to be struggling with acceleration. It seemed to be slow and sluggish. I drove the car home not exceeding 40 mph. Next morning when starting the vehicle the dashboard is lit up with an indication of engine malfunction. I only had to drive the car a mile so I continued on to work but I had no power at all. The car was struggling to make it up a small hill and I had no speed on level ground. I am afraid to drive the vehicle at this point. I have scheduled an appointment but the next question is how much is this going to cost? wow I have only owned Camry's for the past 15 years and thought I would try a Kia. They look nice. Not sure I will keep this vehicle much longer.

- Stafford, VA, USA

problem #8

Jun 052013


  • 62,609 miles
While driving my 2012 Kia Optima sx T gdi I lost accelerations on the highway. I was driving at 55 mph because the car wouldn't accelerate, but it did decrease in speed to a dangerous 20 mph. I tried to use my paddle shifters in hopes that would work, to no avail. I depressed the gas pedal to the floor and the speed did not change. I eventually reached a safe place and shut the car off, waited several minutes and attempted re-starting the car. The car sputtered and paused before eventually starting, then allowed me to drive approximately 100 yards before having the same decreased speed situation again. I was fortunate to drive home at 45 mph and avoid being run off the rode or rear ended by another vehicle or worse... a truck. The next morning I took the car to the dealership and after a diagnostic was informed that the fuel pressure sensor needed to be replaced. Not such bad news but I was shocked that the price quoted to me, by the service manager, is $900. Unbelievable!!! I searched all over the internet and found all the parts that are related to this type issue and nothing, not one part, cost $900. The proposed cost to repair my car is greater than the car payment. As a matter of fact, it cost more than the car payment for my wife's ML500. I have visited Kia forums that speak to problems with the Kia and it seems that a manufacturer is in order. Incidentally, the part is no longer covered by the warranty because I recently passed the 60,000 mile mark. I feel like I am being ripped off to have the car repaired for what will be less than an hour of work to replaced a minor part, that incidentally has a cost of $900. I will be willing to provide any other additional information related to my experience with my 2012 Kia Optima. I should be purchased and Audi.

- Penryn, CA, USA

problem #7

Mar 142013

Optima 4-cyl

  • Automatic transmission
  • 4,800 miles
The contact owns a 2012 Kia Optima. The contact stated that when applying the brakes, the vehicle would surge forward and the engine rpms increased to 6000. The contact stated that the floor mat was not source of the surging. The contact did not take the vehicle to a dealer or mechanic for diagnostic testing or repairs. The contact did not contact the manufacturer. The failure mileage was 4,800. Updated 06/18/13 updated 06/21/2013

- Liverpool, NY, USA

problem #6

Oct 062012


  • 12,187 miles


Gas pedal would not work. Avis puts rubber floor mats over cloth floor mats that have hooks embedded in time to hold the factory floor mats in place. I did not know they had did this. Over the course of several hours of driving the rubber floor mat slid forward under the gas pedal rendering it inoperable; I coasted over to side of road and discovered the problem, pulled the rubber floormat back towards the front seat and it happened a 2nd time a few hours later where I lost complete use of the gas pedal so I put the rubber mats in the trunk. I reported this to avis. An avis rep says this is a standard corporate policy so they can save wear on the cloth rug style floor mats. I asked them to reexamine their corporate policy. I hope your Agency can review this practice and make a recommendation to avis. With all the issue surrounding car accelerator pedals and after market floor mats jamming them it seems they have taken leave of common sense.

- Southington, CT, USA

problem #5

Aug 182012


  • 200 miles
The contact owns a 2012 Kia Optima. While driving approximately 5 mph with the economy mode activated, there was a delayed response upon engaging the accelerator pedal. The vehicle was able to continue in operation. The failure recurred on two different occasions. The contact eventually deactivated the economy mode. The vehicle was towed to an authorized dealer however, the technician was unable to duplicate the failure. The vehicle remained at the dealer for further investigation. The manufacturer was notified of the problem. The approximate failure mileage was 200.

- Walnut Creek, CA, USA

problem #4

Aug 082012


  • 13,800 miles
Was sitting at light and went to take off car felt like it didn't want to shift into gear and had a loud rough grinding noise, all lights on the dashboard came one. Brake light, check engine light, coolant, etc and none of the gauges were working. I stopped at the store and went to leave the car would start up but wouldn't go into gear, it was stuck in park. I had to get it towed to the dealership to have it looked at. I had just had this same problem 1 week ago where all the lights were on and the gauges weren't working and the dealership had supposedly replaced the fuse panel box but that apparently didn't fix the problem. I think that it's a computer or engine issue.

- Mcdonough, GA, USA

problem #3

May 162012

Optima 4-cyl

  • 250 miles
The contact owns a 2012 Kia Optima. The contact stated that the floor mat on the driver side of the vehicle bunched up around the brake pedal and made it hard for the contact to apply the brakes. The contact took the vehicle to the dealer and was given winter floor mats with teeth to help the floor mat grip the floor of the vehicle. The contact stated the standard floor mats were not safe because they would move around too easily. The failure mileage was 250 and the current mileage was 2,000. Updated 9/10/12 the dealer installed a set of all-weather mats, which have teeth which grip the floor more firmly. Updated 09/24/12

- Monroe Township, TX, USA

problem #2

Jan 252012


  • 11,000 miles
The contact owns a 2012 Kia Optima. While driving approximately 5 mph, the vehicle suddenly accelerated independently and crashed into the median. The vehicle was towed to the dealer for diagnostic testing where the technician advised that the front passenger side tire and axle would have to be replaced. The failure recurred four times. The fourth time the failure recurred, the contact crashed into another vehicle. The contact sustained injuries to his right knee. The front passenger sustained injuries to the neck, back and right arm. The rear passenger sustained injuries to the right leg. The passengers were transported to the hospital via ambulance. The driver sought medical attention on his own after the crash. The police reported to the scene and a report was filed. The vehicle was towed to the dealer. The vehicle was taken to an auto body shop for the body damage repair. The manufacturer was made aware of the failure and assigned an engineer to review the information related to the crash. An engineer did not inspect the vehicle. The manufacturer refused to repair the vehicle because they stated there were no defects within the vehicle. The vehicle was not repaired. The VIN was not available. The approximate failure mileage was 11,000.

- Milwaukee, WI, USA

problem #1

Jul 042012

Optima 4-cyl

  • 12,738 miles
For 3 to 5 seconds, no response from engine at idle when accelerator depressed and the car is stopped (e.g., for traffic signal). Then, without warning, the engine went from idle (about 800 RPM) to rapid (surging) acceleration, often with screeching tires. This occurred each time I started from a stopped position during a 493-mile trip. There was no problem after I reached my target driving speed.

- Brunswick, MD, USA

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