Kia Optima Engine problems by year

Special Service Tool to perform the Bearing Clearance Test. Dealership management verbally claimed the engine would not fail the test without actually testing it. Furthermore, dealership management refused to submit the mechanical failure for manufacturer Prior Approval unless the owner paid $688 out-of-pocket for a top-end chemical combustion chamber cleaning. Dealership staff acknowledged the cleaning would not repair a 60 psi cylinder compression mechanical failure, but blocked corporate warranty evaluation. The vehicle remains completely inoperable and disabled at the dealership due to severe internal engine and powertrain failure.

four ignition coils and spark plugs were replaced in August 2026, and the #4 misfire returned within about three months. We have paid out of pocket for repeated repairs since January 2025. The KSDS update was installed at a Kia dealer. The vehicle is now unsafe to drive because misfires can cause sudden loss of power at highway speed, and running low on oil risks engine bearing damage and seizure. We have taken it out of service. I have written to Kia America's executives requesting diagnosis under TSB ENG222 and repair under the Theta II settlement's lifetime warranty. I am asking NHTSA to investigate excessive oil consumption and repeated oil-fouled spark plug misfires in Theta II 2.4L GDI engines in 2016-2020 Kia Optimas.

and a thermostat, did not resolve the underlying issue. Following the engine failure, a Kia dealership reported a cracked engine valve and multiple severely damaged or melted spark plugs, including spark plugs that had recently been replaced. These findings raise serious concerns about progressive internal engine damage and a potentially defective engine. Despite my concerns regarding known Kia engine defects and possible connecting rod bearing issues, the dealership stated it could not perform the bearing clearance test due to the condition of the valves. My case was never submitted to Kia Techline for further investigation. I was initially instructed to provide oil change and maintenance records for consideration of engine replacement assistance, only to later be told that excessive oil consumption was not relevant to my claim. I am extremely concerned that a potentially defective engine experienced progressive damage before suddenly failing on the freeway, placing my life and others at risk. I am requesting that NHTSA investigate this failure and determine whether it is related to known Kia engine defects or an unresolved safety issue affecting other vehicles.

push. I was terrified that I was not going to be able to stop. I was scared I was going to be hit and someone would get seriously injured. I then received a call from Cascade Automotive saying that my engine seized from rod bearing failure but my engine was under warranty under the Kia Engine Class Settlement. I called Kia Consumer service and they said my Vin# qualified and was under warranty. I then had it towed to Kia of Puyallup. They confirmed it was a Rod Bearing failure that caused the seizure and told me it did qualify for the warranty. But then told me since I didn't get the HECU fuse update its void. I told them I never got a notice for the recall. They said it didn't matter and said to fix it, it would be $6700. I called Kia Consumer again and asked what can be done and they said nothing. I asked if they had any record of sending me or my dad ([[redacted]]) the recall notice and they said no and he wasn't in their records as the registered owner. I then asked since they have no record of sending the recall notice to me or my dad and I had no way of knowing about the HECU fuse if the warranty is good now and they said no, I should have looked for recall. There were no warning signs. I have maintained my car and had the oil changed regularly. My safety was put in jeopardy because Kia failed to notify me of a faulty engine and the HECU fuse. I asked for the records saying no notice was given and they said it was against their policy to send that. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

and surrounding traffic. I immediately pulled over at the first safe opportunity and did not continue driving the vehicle. My partner, who was approximately six months pregnant, was traveling with me. We remained stranded along the roadside for approximately three hours awaiting assistance, approximately 202 miles from home. Diagnostic trouble code P1326 was subsequently identified. There were no noticeable knocking, rattling, or ticking noises before or after the incident. The oil-pressure warning light did not illuminate. After the incident, the engine oil level was checked and found to be between the minimum and maximum dipstick markings. Timestamped photographs were taken during the towing process and at dealership drop-off. The vehicle was transported to a Kia dealership, where a bearing clearance test was performed and passed. The dealership also identified an external oil leak. However, the cause of the sudden loss of power and P1326 activation has not been conclusively established. I am reporting this incident because the unexpected and substantial loss of engine power while driving on a mountainous highway created a potentially dangerous situation. I am concerned that the condition could recur and pose a safety risk to other drivers and passengers.

went into limp mode on 10/21/2026, they updated the software again. My focus here is the fact that it is a known issue and they say it still does not meet the parameters for an engine replacement. It is a severe issue that is dangerous and inconvenient to the driver. You are afraid to take it on a trip or even take it on a highway. My 20 year old daughter drives this to college. Can you imagine a car going into limp mode on a majory US highway? Limp mode essentially does not allow a vehicle to go above 2K RPM. You cant go up a hill over 35 and on a highway, on a flat road you "might" be able to go 55 MPH. My daughter goes to college 4 hours away. This creates a very unsafe, dangerous and inconvenient environment. KIA is hoping that they can buy time until these vehicles fail for some other reason and they dont have to pay the cost for a new engine.... ALL at the consumers peril. To put this in perspective, if you have a vehicle with a "low tire pressure" warning, does lowering the sensors parameters fix the problem.... No, it just turns off the warning and you are driving a car with low tire pressure.

a distinct, unfamiliar smell that is not like burning fuel or oil. On October 21, I found the vehicle leaking an opaque, milky tan fluid onto my garage floor. The type and source of the fluid are UNKNOWN. I have photos of the leak. My family and I have stopped driving the vehicle because we believe it is unsafe. We were driving it with our children before these symptoms appeared. Given the history of Theta II engine failures, we are concerned about the risk of engine failure, stalling, or fire while driving. The new symptoms have not yet been diagnosed or confirmed by a dealer. I am arranging for the vehicle to be towed to a Kia dealer for warranty diagnosis. The vehicle and leak are available for inspection. I have reported these issues to the manufacturer under an open customer case.

companies three to four times a week for the last 3 weeks and they both are saying they never received anything from each other. The mechanical issue is very dangerous the car jerks slows down to a very low speed around 30 Mi an hour in the middle of high speed traffic. Is very dangerous I've been without a vehicle for 3 weeks which is slowing down my process to continue to pay my bills I need my vehicle can I get any help from anyone. I feel disrespected taking advantage of and now I'm starting to fall into a financial issue because they cannot communicate with each other to fix an issue that should be covered under the warranty that they said it would and I have documents to prove it INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)