2021 Kia Seltos: misfire or rough idle

Filed Sep 20, 2026 · Engine · CA

Had the software update for piston recall in April 2025, did all the testing and getting codes p0300 all the way to p0305 being that it only has 4 cylinders a 5th cylinder misfire code leads to piston ring failure, it is also burning oil the spark plugs are ashy which I have photo evidence of all of this and they are covered in oil, my car broke down while driving and lost complete engine power I am medically complex. Dealerships are denying the recall as it was "completed" due to a software update. This is a known safety hazard and I could have died. I have all proof it's the spark plugs failing.

Filed Sep 17, 2026 · Engine, Transmission · CT

My check engine light went on and the vehicle was driving sluggish, was louder at higher rpms and had a rough idle. The light went on around Aug 1st, 2026 and that's when I noticed the strange driving. Brought it to my mechanic that week and they got the following codes: p0017, p0014 and p0013. My mechanic thought this may be consistent with other engine issues Kia's had around the year of my car's make. While waiting for an appointment with a dealership, my car stalled out while I was driving it on Aug 5, 2026 and wouldn't turn back on. Luckily I was not on a busy road or a highway when this happened and was able to pull over without injury or damage to the vehicle. I got it towed to a Kia dealership and they took the engine apart and found that a camshaft dowel backed out causing separation inside of the engine. They had to then replace the exhaust cam, phaser, timing chain tensioner and all seals and gaskets needed for the repair. The dealership seemed to know this was a common issue and a quick search on the internet confirms that many other people with Kia engines (particularly Kia Seltos) around 2019-2021 have also had this problem. The car is 6 years old and only has about 85,000 miles on it. It has had all the required maintenance up to this point. The engine disassembling itself on its own does not seem like typical wear and tear to me.

Filed Aug 29, 2026 · Engine · AZ

My 2021 Kia Seltos stalled twice while driving and failed to restart, creating a severe safety hazard. The vehicle was previously inspected twice at a Kia dealer for the Piston Ring Recall (SC209). The dealer diagnosis now shows timing failure codes P0014 and P0017 with misfires. The technician notes that the engine oil is entirely 'metalized' and the oil control valves are contaminated with metal debris. Kia is attempting to charge me $7,182 to fix a failure caused by the exact oil starvation symptoms of their active federal safety defect.

Filed Jul 30, 2026 · Engine · 92,000 miles · OH

The contact owns a 2021 Kia Seltos. The contact stated that on March 13, 2026, the vehicle was serviced under the federal safety agency Campaign Number: 21V259000 (Engine); however; the spark plugs were not replaced when the vehicle was repaired. The vehicle was taken to the dealer, where it was diagnosed with a misfire in the engine associated with the spark plug. The dealer stated that the failure was not associated with the recall. The contact stated that the failure was caused by the dealer not installing new spark plugs during the recall repair. The manufacturer was made aware of the failure and stated that the recall repair was performed and was out of warranty. The failure mileage was approximately 92,000.

Filed Mar 30, 2026 · Engine · PR

Excessive oil consumption Engine damage or failure Ticking noise from the engine Loss of power when driving Rough idle, shaking the car is not able to be used, for safe.

Filed Mar 2, 2026 · Engine · MT

My 2021 Kia Seltos (manufactured April 2020, ~94,000 miles) has the 2.0L Nu MPI engine affected by a known piston oil ring defect. Symptoms include piston noise, excessive oil consumption, rough idle, reduced power, and codes: P1327 (PNSS-detected knock), P0304 (cyl 4 misfire), P0017 (crank/cam correlation error). These indicate progressive cylinder wall scoring from improperly heat-treated rings, risking seizure or fire. Service history shows: • SC209 (Safety Recall 21V‑259) inspection in Jul 2021. • SC209A (PNSS software update) in Feb 2022—explains why P1327 now triggers. • Other campaigns: anti-theft (CS2309/CS2312), AWD ECU (SC242/SC297), ECM logic (SA463). The defect progressed despite early recall work; dealers deny full engine replacement, citing prior completion or shifting coverage. SC209 has no mileage limit—progressive damage qualifies for re-inspection (vibration test, bore scope, compression) and free long block replacement if confirmed. You’ve faced loaner return demands before 2-week period, goodwill denials, and inconsistent coverage. The issue aligns with the federal safety agency concerns (e.g., AQ25001 on similar recall effectiveness).

Filed Feb 27, 2026 · Engine · MT

On [XXX], check engine light came on with P1327 (PNSS piston noise detection). History includes SC209 recall in 2021 (inspection passed, PNSS software added Feb 2022). Now at 94,000 miles with misfire P0304 on cyl 4 and timing correlation P0017—dealer refuses full engine replacement under recall. Service dealer insisted it would be safe to drive 300 miles to Billings, MT from my home base location. Got 5 miles down the road to be left stranded to walk back with no service on a 13 degree day. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Feb 13, 2026 · Engine · WA

On 01/04/26, my vehicle’s Check Engine light came on and the engine was shaking. The next day, my mechanic diagnosed a P0301 code (cylinder #1 misfire), found signs of burning oil and cylinder damage in all cylinders, and noted the car had burned over 2 quarts of oil since the last oil change. He suspected faulty oil rings (previously recalled) and advised immediate dealer repair, warning of possible engine failure or fire hazard. The car had only 42K miles and should have been under warranty, but the dealer refused service because the code was cleared and said the warranty expired 4 months earlier. They claimed recall work was completed in June 2021 and would only help if the check engine light returned. Despite research showing codes are stored in the engine control system, the dealer insisted there was “no way to see the code.” After 10 days, the light didn’t return, so I picked up the car and continued driving, noticing a burning oil smell. On 02/02/26, I returned to the dealer, who offered only an Oil Consumption Test, stating it’s acceptable for the vehicle to burn 1.3 quarts per 1,000 miles—though the car’s oil capacity is just 4.2 quarts. The service advisor suggested I contact Kia USA, which I did on 2/06/26. Kia USA sent a repair order to the dealer, who claimed to be “working on the diagnosis.” Kia USA requested two more business days to follow up. GPS tracking shows the vehicle hasn’t moved except for parking since it was brought in.

Filed Feb 4, 2026 · Engine · CA

The car makes a jumping/jerking movement & at times, something that seems like a misfire happens. All lights go on and the car will do that jerking issue & become un drivable. This happened to me on the road and I was afraid for my safety as I couldn’t get my car to a safe place immediately. Brought it to my mechanic and he gave me forms of a recall regarding 2021 Kia Seltos which is what I have.

Filed Dec 11, 2025 · Engine · MN

I took my car to the dealership for the recall fix on its engine where they put the noise sensors in. I told them my car was burning oil and my car check engine light came on so I took it back in. Just before going in the light went off, but the code was for a misfire in cylinder 2. They did could not recreate the misfire and sealed my engine and told me to bring it back in 1000 miles. During this time the check engine light came on and went off again for the same code. When I brought it back at 1000 miles they could not recreate the misfire and said my car burned 0.77 quarts of oil in 1000 miles and in order for the engine to be bad that it needed to burn 1.0 quarts in that timeframe. They resealed the engine and I am to bring it back again in 1000 miles. A car should burn next to nothing for oil in 1000 miles. So my engine could burn out almost all its oil before a regular oil change and burn up the engine unless I keep adding oil. I am betting the cylinder misfire is because of oil fouling the plug. I could be on the highway and my motor could stall or blowup from lack of oil. Their recall fix is a joke and saying a regular gas enginecan burn up to 1 quart of oil every 1000 miles is ridiculous. This and every car with this engine problem should have the engine properly repaired or replaced

Filed Aug 14, 2025 · Engine · TX

I took my car in last Wednesday to have the recall remedy done I was told my engine was fine my car sat up after that until Monday when I turned it on the check engine light came on and I was told after checking that cylinder 2 was misfiring and apparently my car was in fact not okay. My car went in on Monday and has been sitting in “being inspected “ status since yesterday. I have called and texted multiple times and can not receive and answer as to what is going on nor did they give me a loaner so I have been with out a car for 4 days now. The service department does not answer nor return my calls and just keep routing me to scheduling who apparently can’t tell when what’s going on either.

Filed Apr 30, 2025 · Engine · 53,745 miles · HI

The contact owns a 2021 Kia Seltos. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic where it was diagnosed with an engine misfire and low oil. The contact stated that the vehicle was scheduled for a service appointment for the following week, however the contact experienced the failure prior to the scheduled appointment date. The dealer was made aware of the failure, and the contact was informed that the recall repair was not available at the scheduled location any longer. The contact received notification of the federal safety agency Campaign Number: 25V099000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was 53,745. Parts distribution disconnect.