2024 Kia K5 Problems: 18 Known Issues

On the 2021-2024 Kia K5, multiple K5 owners and NHTSA complaints document unexpected, uninitiated hard braking events triggered by the Forward Collision Avoidance Assist system in the absence of any actual obstacle. These phantom braking events occur most commonly on highways, elevated roads, or in areas with overhead signs, bridges, or guardrails that the front radar and camera system misidentifies as collision threats. The issue represents a safety concern as following vehicles may be unable to react in time, increasing rear-end collision risk.

On the 2021-2024 Kia K5, owner reports and NHTSA complaints describe the forward-facing camera/rain sensor bracket at the windshield separating or losing adhesion, which can cause the camera module to shift out of position. This can trigger driver-assistance warnings and disable features like Lane Following Assist/Forward Collision-Avoidance Assist and/or cause erratic automatic wiper behavior. The issue is typically tied to windshield bracket bonding/installation and is often noticed after temperature swings or windshield replacement.

On the 2021-2024 Kia K5, nHTSA complaints and owner reports note intermittent EPB warnings and Auto-Hold faults on Kia K5, sometimes accompanied by the parking brake not applying/releasing as expected. The issue is commonly linked to EPB actuator/motor faults, wiring/connector issues at the rear calipers, or control module logic faults. Owners typically experience warning messages, chimes, and loss of Auto-Hold functionality.

On the 2021-2024 Kia K5, on 1.6T turbocharged K5 variants, some owners and NHTSA complainants have reported a hissing sound from the brake booster area upon brake pedal application, accompanied by a noticeably harder brake pedal and reduced power assistance. The GDi turbocharged engine uses an electric vacuum pump to supplement braking assist; failures or leaks in the vacuum pump, vacuum check valve, or booster hose connection reduce available vacuum and compromise brake pedal feel and stopping distance. This has been flagged as a safety concern in NHTSA filings.

On the 2021-2024 Kia K5, owners of K5 models equipped with the 2.5L naturally aspirated GDI engine (SmartStream G2.5) have reported excessive oil consumption between change intervals, sometimes consuming over a quart per 1,000 miles. The root cause is linked to piston ring sealing tolerances that allow oil to enter the combustion chamber, producing blue smoke from the exhaust on cold starts and acceleration. NHTSA complaint database reflects multiple owners reporting this on 2021-2023 model years, with Kia issuing TSB guidance for inspection and potential short block replacement.

On the 2021-2024 Kia K5 1.6T, owner reports and NHTSA complaints on 1.6L turbo K5 models describe oil seepage/leaks around the turbocharger oil feed/return lines or related seals, sometimes producing a burning oil smell and light smoke after driving. Heat cycling can harden seals or loosen fittings, allowing oil to drip onto hot exhaust components. Owners typically notice odor in the cabin at stops and oil residue near the turbo area.

On the 2021-2025 Kia K5 2.5L Theta II, the 2.5L Theta II engine in certain K5 models has experienced knock sensor faults and engine knock concerns. The knock sensor may trigger false positives or fail to detect actual detonation, causing the ECU to either retard timing unnecessarily (reducing power) or fail to protect against harmful knock. Kia issued a software update to improve knock detection logic, but some owners report persistent issues after the update.

On the 2021-2024 Kia K5, a number of K5 owners have reported premature rear wheel bearing failure, typically presenting as a low-pitched humming or growling noise that changes with vehicle speed and varies when turning left or right. The issue has been observed on both FWD and AWD variants and appears linked to bearing press-fit tolerances in the rear knuckle assembly. NHTSA complaints and owner forums document failures occurring well before expected service life, sometimes as early as 25,000 miles.

On the 2021-2024 Kia K5, kia K5 owners report creaking, popping, or groaning noises from the front suspension during steering input, especially at low speeds or when parking. The issue is often tied to strut mount bearings binding or premature wear, sometimes exacerbated by moisture intrusion. The noise can be mistaken for steering rack issues but is frequently localized to the upper strut mounts.

On the 2021-2024 Kia K5, k5 models equipped with the 8-speed conventional automatic transmission (paired with the 2.5T Turbo engine in higher trims) have generated complaints of harsh, jerky upshifts—particularly the 1-2 and 2-3 shifts—and in some cases the transmission entering limp mode (restricted to lower gears) after a fault is detected. This is distinct from the DCT shudder issue and specifically affects the hydraulic 8AT unit. TSBs from Kia/Hyundai on the shared 8AT platform have addressed TCU software logic for shift pressure and torque converter clutch engagement.

On the 2021-2024 Kia K5 2.5L T-GDI, kia bulletin TRA100 documents clutch judder on some 2021 model year and later K5 GT vehicles equipped with the 2.5L T-GDI engine and 8-speed wet dual-clutch transmission. Kia defines the condition as body vibration, without steering-wheel shudder, during a controlled creep-driving test below 5 mph. The bulletin does not establish a general software defect across all K5 trims or recommend a transmission-fluid flush.

On the 2021-2024 Kia K5, owner reports and NHTSA complaints note exterior door handles and/or door lock actuators failing, leading to doors that won’t open from outside (and sometimes inside) or won’t lock/unlock reliably. Failures are commonly tied to actuator motor wear, latch mechanism binding, or linkage issues inside the door. Owners often report intermittent operation that progresses to complete failure.

On the 2021-2024 Kia K5, k5 owners across multiple model years have reported premature paint chipping on the hood and roof panels, with the clear coat peeling in flakes or bubbling in affected areas. This is documented in Kia owner forums and in some NHTSA complaints, particularly in darker colors such as Gravity Gray and Aurora Black Pearl. The issue is attributed to insufficient paint film thickness or adhesion on horizontal panels most exposed to UV radiation and road debris impact, and is a known issue on the shared Sonata/K5 platform. Some owners have had repaints or touch-up coverage denied under warranty as cosmetic exclusions.

On the 2021-2025 Kia K5, the electric trunk latch mechanism on the K5 is prone to sticking or failing to release, leaving the trunk locked. The issue is more common in cold weather when moisture gets into the latch mechanism and freezes. The trunk release button on the key fob, interior button, and exterior trunk handle may all fail to open the trunk when the latch is stuck. Some owners report the latch actuator motor failing entirely, requiring manual release from inside the trunk via the emergency release handle.

On the 2021-2025 Kia K5, the Advanced Driver Assistance Systems on the K5 — including Lane Keep Assist, Forward Collision Avoidance, and Blind Spot Monitoring — intermittently throw calibration faults and disable themselves. The forward-facing camera behind the windshield and radar sensor in the front bumper are sensitive to windshield contamination, extreme temperatures, and minor front-end impacts. After a windshield replacement, the ADAS sensors require recalibration that many glass shops skip or perform incorrectly.

On the 2021-2025 Kia K5, the K5 infotainment system — both the 8-inch and 10.25-inch displays — experiences random screen blackouts, freezes, and spontaneous reboots. The screen may go completely black while driving, losing access to navigation, backup camera, and climate controls. Some owners report the system rebooting in a loop. The issue is typically software-related but can also be caused by a failing display head unit. Android Auto and Apple CarPlay connections can trigger or worsen the problem.

On the 2021-2024 Kia K5, k5 owners report blower motors that begin squealing, chirping, or rattling and may intermittently stop, reducing cabin airflow. The condition is typically caused by blower motor bearing wear, debris intrusion, or resistor/control issues depending on trim. Symptoms often start as noise at certain fan speeds and progress to reduced or no airflow.

On the 2021-2024 Kia K5, k5 owners with heated and ventilated seat packages have reported failures of the seat heating elements—particularly in the rear seat areas—as well as ventilation fan noise or complete fan failure in the front seats. Seat heating elements can develop open circuits causing partial or complete loss of heat, often on one side of the seat. Ventilated seat blower motors have been reported to produce rattling or grinding noises, sometimes from debris infiltration or motor bearing wear, a known issue documented on multiple Kia and Hyundai shared platforms.