Two problems related to engine grinding noise have been reported for the 2012 Kia Motor Optima. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Kia Motor Optima based on all problems reported for the 2012 Optima.
Transmission issues: between 2nd and 3rd gear. Would lag then jerk the car with some torque once it caught 3rd gear. Had to get 2 replacement transmissions because of this issue. Also engine seizer issue, my engine started to seize when I was going 45 miles an hour with alot of traffic behind me. Then all of a sudden it started making loud thunking noices then a very loud grinding noise and then I was stuck on a road not being able to get above 22 miles and hour, there was no shoulder to pull over. And I was stuck trying to go uphill and all these cars behind me. I ended up having to stop the car and leave it in the middle of a 2 lane road on a hill with the emergancy break on. Kia knew it was another seized engine which I thought it was my transmission again which I had brought in because this 3rd transmission was having the skilling issues around 20-25miles and hour, but after they knew I wasnt going to buy another kia again they wouldnt fix my trans that should probably be recalled anyways. But they thought it was another Optima seized engine, and even though all Optimas are recalled for this exact same issue, they say that mine isnt covered becasue its a hybrid and has a motor in the car also so its different set up. But theres are others online with this kia Optima 2011-2013 hybrid engine seizer just like all the other Optimas. And I think the hybrids should be included in the recall. As we are having the same issues. This was a very dangerous issue.
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.