2021 Kia K5 Reliability Score & Common Problems

Owners report several power train issues with the 2021 Kia K5, primarily involving transmission failures and erratic gear shifting. Complaints frequently mention symptoms such as loss of power, transmission slipping, and delays in shifting gears, often accompanied by engine revving without acceleration. These issues appear at varying mileage, with some incidents occurring as early as 4,600 miles. Multiple owners describe situations where the vehicle loses power suddenly, sometimes in traffic or on highways, posing potential safety risks. Additionally, some reports indicate that transmission replacements have been necessary shortly after purchase, suggesting potential concerns for used car buyers regarding reliability and repair needs.

Owners report several recurring engine-related issues with the 2021 Kia K5. Complaints frequently mention sudden loss of power, with some incidents occurring at highway speeds and leading to dangerous situations. Multiple owners describe engine shutoffs while driving, often followed by the vehicle entering limp mode. Issues with the turbo, such as antifreeze leaking into the head gasket, are noted, typically at mileages ranging from 68,000 to over 100,000 miles. Additionally, some owners report overheating problems and coolant system failures, with symptoms including the escape of antifreeze vapors and strong coolant odors. These issues pose safety risks, including potential accidents due to unexpected engine shutdowns and loss of vehicle control.

Owners of the 2021 Kia K5 report several structural issues, with the most common being components falling off the vehicle. Complaints frequently mention engine covers and underbody panels detaching, often while driving, which can create road hazards and potential safety risks. Some owners also describe issues with the fuel tank swelling, leading to floor deformation and safety concerns due to gasoline spraying when the gas cap is opened. Additionally, there are reports of sunroofs shattering unexpectedly and abnormal wind noise from rear doors. These issues are noted at various mileages, with some occurring relatively early in the vehicle's lifespan. Safety implications include potential for accidents due to falling parts and the risk of fire from fuel tank issues.

Owners of the 2021 Kia K5 frequently report issues with airbag non-deployment during accidents. Complaints describe situations where airbags fail to deploy in various crash scenarios, including high-speed rear-end collisions and frontal impacts, resulting in multiple injuries and at least one fatality. Several reports highlight that these incidents occur at speeds between 30 and 70 mph. Additionally, one owner mentions a related issue with a folding seat latch failure during a collision. The safety implications are significant, with complaints consistently noting the lack of airbag activation in severe crashes, which prospective buyers should consider.

Owners report persistent steering issues with the 2021 Kia K5, primarily involving the vehicle pulling sharply to the right and the steering wheel failing to center, requiring constant correction. Several complaints indicate that the steering wheel can become stiff or lock up, sometimes accompanied by multiple warning lights activating. These problems often occur at various mileage points, with some reports noting issues as early as a few months after purchase. Safety implications are significant, as the steering malfunctions may lead to loss of control while driving. Multiple owners describe attempts to resolve these issues through dealership visits without successful repair, highlighting ongoing concerns with the vehicle's steering system.

Owners of the 2021 Kia K5 frequently report issues with the fuel system, primarily involving the fuel tank swelling or expanding. Complaints often describe symptoms such as the rear seat rising unexpectedly, strong fuel odors entering the cabin, and erratic fuel gauge readings. Several reports involve the fuel tank hanging down or leaking, with occurrences typically noted at mileages ranging from 86,000 to 116,000. Safety implications are evident, with one reported injury linked to the rear seat popping up. Prospective buyers should be aware of these patterns and the potential for safety risks associated with the fuel system.

Owners report several issues with the 2021 Kia K5's service brakes, including shaking during braking or adaptive cruise control use, which may lead to a loss of control. Some complaints mention brake pads that are easily worn, broken, or rusty. Another issue involves the brake booster, which exhibits a hissing sound due to air leakage, impairing brake functionality. Multiple owners describe frequent premature rotor warping, with one owner noting this issue after 24,000 miles and having replaced rotors five times. These reports suggest potential safety implications, especially concerning brake efficiency and vehicle control.