The car will run fine, then engine will start to misfire. Then lose power (put the gas petal to the floor and car does not move and the engine does not rev up due to the increased gas flow.) the engine will shutter and turn off. Le it sit for 5 to 10 minutes and the car will start. The car will drive for another 5-10 minutes and shut off and will not run for start for several minutes and will not drive beyond couple hundred feet. We have replaced the cam sensor, crank sensor, egr valve, spark wires, sparks, coil packs, water pump, all belts, alternator, battery, and short block rebuild (warranty work). The code was the first time was misfire in 1 and 4 cyders, after the rebuild the code is misfire 2 and 3 cyders. We have the computer reprogrammed twice. The dealership have no clue.

- Ammon, ID, USA

The contact owns a 2005 Kia Optima. While driving approximately 35 mph on normal road conditions, the vehicle stalled without warning. The check engine warning indicator illuminated intermittently on the instrument panel. The vehicle was taken to the authorized dealer, but they were unable to duplicate the failure. The vehicle was taken back to the dealer on three separate occasions for the same failure, but there was no resolution. Recently, the crankshaft sensor was replaced under the service warranty; however, the failure recurred a few days later. The vehicle is in the process of being repaired. The VIN was unknown. The failure mileage was 24,500 and current mileage was 25,000. Updated 5/18/09 updated 05/20/09.

- Spring Grove, PA, USA

I just bought my 05 Optima. It also turns itself off--when it wants to. At first-it just did it in reverse. Then it started doing it driving down the highway. I took it to the dealer-who also, could not duplicate it. This is scary driving this car. You have no warning--it just turns everything off--like you never started the car at all.

- Norman, OK, USA

: the contact stated the vehicle intermittently stalled without warning. The vehicle restarted each time and was taken to the dealership. The dealership was unable to determine the problem.

- Meridian, MS, USA

: the contact stated without incident the check engine light illuminated. The dealership determined the fuel cap was not properly tightened, then checked for diagnostic codes. There were no codes found and the light was turned off. Fifteen minutes after the vehicle was taken from the lot, the light illuminated again. The vehicle was taken back to the dealership who expressed the fuel cap was not tight enough and there were still no codes. The light was turned off. The light illuminated a third time; although the vehicle was not refueled.

- Westampton, NJ, USA