2016 KIA Cadenza problems

ENGINE

My 2016 Kia Cadenza (VIN [XXX] ) experienced repeated overheating, coolant loss, and eventually white exhaust smoke consistent with internal coolant intrusion. The issue began mid-2025 and worsened over time. Despite reporting overheating and coolant loss to Central Kia of Plano, the dealership failed to diagnose the problem, did not escalate to Techline, and did not check or apply Kia Service Action WTY039, which was active. They returned the vehicle to me still overheating, forcing me into multiple out-of-pocket repairs for coolant, radiator, radiator fan, and water pump replacement. None resolved the issue, and the vehicle became unsafe to drive due to rising temperature and smoke. A second dealer, Mesquite Kia, performed a proper diagnosis. Kia Corporate approved an engine replacement under WTY039 on 11/6/25, and the repair was completed on 11/29/25, confirming the overheating was caused by a covered engine defect. Kia Corporate later denied reimbursement for prior repair attempts by blaming “3rd party repairs,” ignoring that the dealership’s misdiagnosis forced me to seek outside help. This defect created safety hazards including overheating while driving, risk of stalling, coolant intrusion, and visible smoke. I am requesting NHTSA review Kia’s handling of this defect and the failure of Central Kia of Plano to diagnose or escalate a known engine issue, which allowed a safety defect to worsen. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11702878 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

I am submitting this complaint regarding a 2016 Kia Cadenza (VIN: [XXX] ) and Kia’s repeated failure to properly diagnose or repair a serious overheating/safety defect despite this being a well-documented and known issue affecting these engines. Vehicle and Service Information •Vehicle: 2016 Kia Cadenza (VIN: [XXX] ) •Mileage: ~129,608 •Dealer Involved: Central Kia of Plano (Plano, TX) •Repair Order #: [XXX] •Dates: [XXX] Issues 1.Overheating / Known Engine Defect •My vehicle overheats, especially with the A/C on or at idle. •Kia has already been directed to issue extended warranties on these engines due to systemic defects (including bearing wear, engine failure, and overheating). •Despite this, Kia continues to deny or delay proper repairs and instead authorized the dealer to replace only a cooling fan relay, which did not fix the defect. 2.Dealer Misconduct •Central Kia of Plano kept my vehicle for 10 days, charged me $269.92, and returned the vehicle still overheating. •I was told a Techline case would be submitted, but I have confirmed this was never done. 3.Incomplete Recall Repairs •I requested completion of open recalls: •SC232 – Windshield Bonding •SC284VG – HECU Fire Risk •The dealer marked one as complete and the other as pending, but I have no confirmation in Kia’s system that either was properly completed. 4.Corporate Inaction •I have multiple open cases with Kia Corporate, but they have failed to escalate or reassign me to a reputable dealer. •Despite the extended warranty obligation, Kia has not replaced the engine or confirmed a permanent repair. Why I Am Contacting NHTSA •This is not an isolated issue — it is a known safety defect across these engines. •Kia has been required to extend warranties for this exact defect but is failing to honor that coverage by stalling, misdiagnosing, and leaving vehicles unsafe. •My vehicle remains unsafe to drive INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11684923 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

I am submitting this complaint regarding a 2016 Kia Cadenza (VIN: [XXX] ) and Kia’s repeated failure to properly diagnose or repair a serious overheating/safety defect despite this being a well-documented and known issue affecting these engines. Vehicle and Service Information •Vehicle: 2016 Kia Cadenza (VIN: [XXX] ) •Mileage: ~129,608 •Dealer Involved: Central Kia of Plano (Plano, TX) •Repair Order #: [XXX] •Dates: [XXX] Issues 1.Overheating / Known Engine Defect •My vehicle overheats, especially with the A/C on or at idle. •Kia has already been directed to issue extended warranties on these engines due to systemic defects (including bearing wear, engine failure, and overheating). •Despite this, Kia continues to deny or delay proper repairs and instead authorized the dealer to replace only a cooling fan relay, which did not fix the defect. 2.Dealer Misconduct •Central Kia of Plano kept my vehicle for 10 days, charged me $269.92, and returned the vehicle still overheating. •I was told a Techline case would be submitted, but I have confirmed this was never done. 3.Incomplete Recall Repairs •I requested completion of open recalls: •SC232 – Windshield Bonding •SC284VG – HECU Fire Risk •The dealer marked one as complete and the other as pending, but I have no confirmation in Kia’s system that either was properly completed. 4.Corporate Inaction •I have multiple open cases with Kia Corporate, but they have failed to escalate or reassign me to a reputable dealer. •Despite the extended warranty obligation, Kia has not replaced the engine or confirmed a permanent repair. Why I Am Contacting NHTSA •This is not an isolated issue — it is a known safety defect across these engines. •Kia has been required to extend warranties for this exact defect but is failing to honor that coverage by stalling, misdiagnosing, and leaving vehicles unsafe. •My vehicle remains unsafe to drive INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11684923 — an unverified report by a vehicle owner.

ENGINE

I am submitting this complaint regarding a 2016 Kia Cadenza (VIN: [XXX] ) and Kia’s repeated failure to properly diagnose or repair a serious overheating/safety defect despite this being a well-documented and known issue affecting these engines. Vehicle and Service Information •Vehicle: 2016 Kia Cadenza (VIN: [XXX] ) •Mileage: ~129,608 •Dealer Involved: Central Kia of Plano (Plano, TX) •Repair Order #: [XXX] •Dates: [XXX] Issues 1.Overheating / Known Engine Defect •My vehicle overheats, especially with the A/C on or at idle. •Kia has already been directed to issue extended warranties on these engines due to systemic defects (including bearing wear, engine failure, and overheating). •Despite this, Kia continues to deny or delay proper repairs and instead authorized the dealer to replace only a cooling fan relay, which did not fix the defect. 2.Dealer Misconduct •Central Kia of Plano kept my vehicle for 10 days, charged me $269.92, and returned the vehicle still overheating. •I was told a Techline case would be submitted, but I have confirmed this was never done. 3.Incomplete Recall Repairs •I requested completion of open recalls: •SC232 – Windshield Bonding •SC284VG – HECU Fire Risk •The dealer marked one as complete and the other as pending, but I have no confirmation in Kia’s system that either was properly completed. 4.Corporate Inaction •I have multiple open cases with Kia Corporate, but they have failed to escalate or reassign me to a reputable dealer. •Despite the extended warranty obligation, Kia has not replaced the engine or confirmed a permanent repair. Why I Am Contacting NHTSA •This is not an isolated issue — it is a known safety defect across these engines. •Kia has been required to extend warranties for this exact defect but is failing to honor that coverage by stalling, misdiagnosing, and leaving vehicles unsafe. •My vehicle remains unsafe to drive INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11684923 — an unverified report by a vehicle owner.

VISIBILITY:WINDSHIELD

The contact owns a 2016 Kia Cadenza. The contact stated that there was water and air leaking through the windshield of the vehicle. The vehicle was taken to the dealer to be repaired under NHTSA Campaign Number: 22V158000 (Visibility); however, the dealer inspected the vehicle and informed the contact that the repair was not necessary. The contact stated that while the vehicle was at the car wash, a significant amount of water leaked through the windshield, causing the contact to be soaked. The contact stated that upon attempting to wipe the interior of the windshield, the windshield was unsecured and almost separated from the vehicle. The contact stated that the windshield could be pushed forward. The contact was able to put the windshield back into place. The dealer was not informed of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was unknown.

NHTSA complaint #11660507 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

While driving down the highway, I heard a loud boom and my sunroof exploded sending glass everywhere all through the car with my kids in the backseat. Driving straight on the highway at 60 miles per hour and nothing to hit the glass, Something is definitely wrong with the pano sunroof on these cars.

NHTSA complaint #11649124 — an unverified report by a vehicle owner.

VISIBILITY

The contact owns a 2016 Kia Cadenza. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the front windshield, after which she observed that the windshield had begun to crack and was leaking. The vehicle was taken to the dealer, who diagnosed a failure with the windshield bonding. The vehicle was repaired, but the failure reoccurred. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 22V158000 (Visibility) the VIN was included, and the vehicle had been repaired. The manufacturer was notified of the failure but provided no assistance. The failure mileage was unknown.

NHTSA complaint #11586595 — an unverified report by a vehicle owner.

SERVICE BRAKES, HYDRAULIC

The contact owns a 2016 Kia Cadenza. The contact received notification of NHTSA Campaign Number: 23V652000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was made aware of the issue and confirmed that parts were not yet available. The manufacturer was made aware of the issue and confirmed that parts were not yet available. The contact had not experienced a failure. VIN tool confirms parts not available.

NHTSA complaint #11585916 — an unverified report by a vehicle owner.

SERVICE BRAKES, HYDRAULIC

The contact owns a 2016 Kia Cadenza. The contact received notification of NHTSA Campaign Number: 23V652000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

NHTSA complaint #11561041 — an unverified report by a vehicle owner.

VISIBILITY:WINDSHIELD

The contact owns a 2016 Kia Cadenza. The contact stated that there was water leaking into the vehicle from the top of the front windshield. There were no warning lights illuminated. The contact called the local dealer, who stated there was no recall. The manufacturer was contacted and referred the contact to the dealer. The vehicle was taken back to the local dealer to be repaired under NHTSA Campaign Number: 22V158000 (Visibility). The dealer diagnosed the vehicle and informed the contact that the front windshield was cracked and declined to perform the repair. The vehicle was not repaired. The manufacturer was contacted again and informed the contact that the cracked windshield nullified the recall repair. The failure mileage was approximately 140,000.

NHTSA complaint #11548019 — an unverified report by a vehicle owner.

VISIBILITY

The contact owns a 2016 Kia Cadenza. The contact stated that there was water leaking into the vehicle from the top of the front windshield. There were no warning lights illuminated. The contact called the local dealer, who stated there was no recall. The manufacturer was contacted and referred the contact to the dealer. The vehicle was taken back to the local dealer to be repaired under NHTSA Campaign Number: 22V158000 (Visibility). The dealer diagnosed the vehicle and informed the contact that the front windshield was cracked and declined to perform the repair. The vehicle was not repaired. The manufacturer was contacted again and informed the contact that the cracked windshield nullified the recall repair. The failure mileage was approximately 140,000.

NHTSA complaint #11548019 — an unverified report by a vehicle owner.

VISIBILITY

The contact owns a 2016 Kia Cadenza. The contact received notification of NHTSA Campaign Number: 22V158000 (Visibility) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was made aware of the issue. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA complaint #11523845 — an unverified report by a vehicle owner.

ENGINE

Per the Kia dealer head bolts have loosened up which have resulted in engine failure.

NHTSA complaint #11473008 — an unverified report by a vehicle owner.

SUSPENSION

While driving, I heard a loud pop followed by a loud grinding noise. I wqs able to pull over and noticed the passenger front side of the car was lower than the rest of the car. At around 75k the passenger side strut went out. Fast forward 2 months later, driving my car the same thing happened but to the drivers side. Both struts needing replaced by 80k. Definitely should be a recall on these struts as this seems very premature and alot of other people with this car have had this problem.

NHTSA complaint #11455500 — an unverified report by a vehicle owner.

VISIBILITY:WINDSHIELD

The Windshield is a defect on the cadenzas, as the seals break on them. It lifts up while driving or even shutting my doors, which I see as a safety hazard. It causes water to leak into the car by where my feet are and from the top of the windshield as well. I believe this is causing my car and other cadenzas to also have electric issues since i’ve had, 7 speakers blew, back up camera glitched and stopped working, sunroof stopped working and i’ve had signals / sounds stop working as well a shot throttle all before 24,000 miles.. Kia has been giving me a run a round with trying to fix my windshield and still has yet to do so. I see this as a huge safety issue. What happens if I hit a bump and it falls off when I’m driving? It could cause a huge accident and or killing myself and others. At first, I thought this was my fault.. but then Kia said it looked like there was no influence I had done anything to it (despite still not replacing it for me). I decided to do some research. I ended up finding valuable information as I found an online forum where cadenza owners state their problems with the vehicle. Mostly all the issues were a loose windshield causing water to leak into the car / and electrical issues similar to mine as a result. I then found a Kia Cadenza forum page on facebook where people were saying the same things. Facebook page is called Kia Cadenza K7 Owners. I have pictures of my cars issues on the windshield and complaints of others going through the same issue.

NHTSA complaint #11432257 — an unverified report by a vehicle owner.

ENGINE

THE CONTACT OWNS A 2016 KIA CADENZA. THE CONTACT STATED UPON STARTING THE VEHICLE, A LOUD RATTLING SOUND WAS COMING FROM THE ENGINE COMPARTMENT. THE CONTACT STATED NO WARNING LIGHT WAS ILLUMINATED. THE VEHICLE WAS TAKEN TO THE LOCAL DEALER AND DIAGNOSED HOWEVER, THE MECHANIC STATED THERE WAS NOTHING TO REPAIR OR REPLACE. THE VEHICLE WAS NOT YET REPAIRED. THE CONTACT RELATED THE FAILURE TO AN UNKNOWN RECALL. THE MANUFACTURER HAD NOT BEEN INFORMED OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 42,674.

NHTSA complaint #11417823 — an unverified report by a vehicle owner.

VISIBILITY:SUN/MOON ROOF ASSEMBLY

ON DECEMBER 6, 2016 MY SUNROOF EXPLODED WHILE DRIVING DOWN THE FREEWAY. THE EXPLOSION WAS SO LOUD AND VIOLENT I THOUGHT I WAS SHOT. SHARDS OF GLASS RAINED DOWN ON MY HEAD. I WAS ABLE TO AVOID A VEHICLE COLLISION, BUT WAS VERY SHAKEN UP ABOUT THE ORDEAL. MY RIGHT EAR FELT DEAF AND I NOTICEABLE HAVE LESS HEARING AS A RESULT OF THE EXPLOSION.

NHTSA complaint #10934856 — an unverified report by a vehicle owner.

STRUCTURE:BODY

ON DECEMBER 6, 2016 MY SUNROOF EXPLODED WHILE DRIVING DOWN THE FREEWAY. THE EXPLOSION WAS SO LOUD AND VIOLENT I THOUGHT I WAS SHOT. SHARDS OF GLASS RAINED DOWN ON MY HEAD. I WAS ABLE TO AVOID A VEHICLE COLLISION, BUT WAS VERY SHAKEN UP ABOUT THE ORDEAL. MY RIGHT EAR FELT DEAF AND I NOTICEABLE HAVE LESS HEARING AS A RESULT OF THE EXPLOSION.

NHTSA complaint #10934856 — an unverified report by a vehicle owner.