New user, I own a 2021 no problems until today, cylinder 1 and 6 miss fired for one key cycle

[ic_craftsman]

I live in a cold climate pulled the car out of a warm garage into cold engine only ran 2 min. 8 hours later I started the car and pulled it back in again only ran engine for 2 min. Next morning I started the car in the garage and engine ran rough I shut it down and scanned for codes and got a P0301 and P0306 which are cylinder misfires. I restarted the car and the engine was running smoothly. I took it to Kia dealer who reported there were no codes and note I did not clear the codes I found. They said sometimes the codes clear with a number of key cycles. That may be true but I wonder what caused the misfires in the first place? Was it the cold start short run time and shutdown? Any educated guesses are requested because I am about to take the car on a 30 day multistate trip that will be at least 2500 miles.

 

[tpgh]

I wouldn’t worry if this was the first time. Likely the cold (how cold?) with the short running times caused this.

 

[Tellmeride]

I wouldn’t worry if this was the first time. Likely the cold (how cold?) with the short running times caused this.

This can't be the cold as he said the car is stored in a warm garage. I park mine in the driveway in the frigid teens and single digits every winter, nothing like this ever happened. This is a big problem my friend.

 

[WesCollins]

Coulda been some condensation around the computer/electronics with the drastic temp changes. Made timing off. If it was mechanical then the sparkle maker mighta had a hiccup. No sparkle=no boom. I doubt injectors froze up on 2 different cylinders. This is profesh redneck advice, replace engine immediately with a quadruple turbo V-8 and it’ll fix it. A 4” lift helps a lot also.

______________________________

 

[ic_craftsman]

I wouldn’t worry if this was the first time. Likely the cold (how cold?) with the short running times caused this.

20 degrees

 

[Tellthemride]

I live in a cold climate pulled the car out of a warm garage into cold engine only ran 2 min. 8 hours later I started the car and pulled it back in again only ran engine for 2 min. Next morning I started the car in the garage and engine ran rough I shut it down and scanned for codes and got a P0301 and P0306 which are cylinder misfires. I restarted the car and the engine was running smoothly. I took it to Kia dealer who reported there were no codes and note I did not clear the codes I found. They said sometimes the codes clear with a number of key cycles. That may be true but I wonder what caused the misfires in the first place? Was it the cold start short run time and shutdown? Any educated guesses are requested because I am about to take the car on a 30 day multistate trip that will be at least 2500 miles.

How much gas was in the tank? Maybe low tank caused condensation buildup or air in the fuel pump?

 

[ic_craftsman]

How much gas was in the tank? Maybe low tank caused condensation buildup or air in the fuel pump?

Gas tank was down to 1/4 left. I will note that once the rough idle started, it continued only until another (one) key cycle occurred. Water in the gas can cause cylinder misfires but I am unsure if there was enough condensation to cause this and one would assume that if that were the problem it would extend through a second key cycle. Thanks for the suggestion!

 

[Javi]

Just an observation, your engine ran rough, that is why you did a scan, That indicates to me it is not likely to be a sensor problem.

If you feel comfortable doing so, pull the two plugs. If the electrodes look okay check for cracks in the porcelain with a magnifying glass.

Best of luck.

______________________________

 

[2020Telly]

I agree it could be condensation in the tank. I don’t think it’s unusual in weather with temperature changes. It could also just be dirty injectors which may also happen on a GDI engine.

If it drives fine normally, the simplest and cheapest thing I would do is go to my local auto parts store and pick up two of these bottles. Put one in before your long trip following the instructions. While on the trip only fill up at name brand gas stations (87 only) that likely use additives and have cleaning agents. After your trip try the second bottle again following the instructions.

All gas stations in the US contain amounts of ethanol for environmental purposes even if you only need/want regular 87 octane. The Telluride is not an ethanol burning vehicle. Yes, some amount is okay and better for the environment but too much ethanol can retain some water in the tank along with regular condensation and that could lead to misfires. Clean gas and a long trip should help clean out a GDI engine.

The Chevron Techron additive is very popular and the one that Kia specifically mentions in the manual. It’s also the additive that Chevron and Texaco gas stations use.

Good luck.