2018 Mazda CX-9 Problems

While driving at highway speed in heavy rain the oil light suddenly came on followed within 30 seconds by an urgent need to immediately stop the car due to overheating. There was no radiator fluid left due to the sudden and catastrophic structural failure caused by a known manufacturing defect. Mazda calls it csp-11. They did NOT do a recall even though a situation such as this is clearly life-threatening. They offer an extended warranty to fix the problem fully up to 120,000 miles. Our car has 124,000 miles. Two months ago it would have been fully repaired at no cost but now they want in excess of 11 THOUSAND DOLLARS. I have spoken to more than 6 people in customer service, 2 supervisors, and they are ADAMANT they will not cover one single penny of repair even though this was not due to wear and tear, but due to a known and recognized manufacturing defect which they have since corrected in newer cars. First, this should have been a full recall since having this happen with no warning is without a doubt life threatening. If an inexperienced teenager had been driving and their engine suddenly seized, they likely would have died, and taken adjacent cars with them. Second, why is this limited extended warranty allowed, it is arbitrary and capricious to say they will fix their mistake up to 120,000 miles but then in an 8-year-old car they will pay nothing? Prior to this there was no advance warning, no fluid leak, and the car had been serviced regularly without any mechanic noticing anything. 3/14/26 repair rear brake pads/rotors 113,896 miles 7/10/26 oil change/tire rotation 123,544 miles 8/7/26 Catastrophic failure due known manufacturing defect csp-11. Brought to Mazda dealer and they confirmed the hole in engine caused by this defect that has an extended warranty. Car still sitting at dealership a month later, now, like a brick, because who has $11,000 in their pocket?

My 2018 Mazda Cx-9 equipped with the skyactiv-g 2.5T developed a serious cylinder-head/cooling-system failure. The vehicle began to lose coolant with no apparent external leak and subsequently displayed and engine -overheating warning. It continued to lose coolant after a flush. The Mazda dealership inspected the vehicle and diagnosed a warped cylinder head; I was also advised that the engine oil was milky, indicating coolant contamination. The affected component is the engine cylinder head/cooling system. This condition created a safety concern because loss of coolant and overheating can lead to severe engine damage or engine failure and potentially leave the vehicle disabled while driven. Mazda has formally documented a cylinder head coolant leak condition in certain 2016-2020 CX-9 2.5T, including cracks around the cylinder head, exhaust manifold area, and states that the cylinder hear/exhaust manifold gasket design was modified to address the condition. Mazda then established customer service program CSP11, extending coverage for the specific cylinder head coolant leak condition to 10 years/120,000 miles, whichever comes first. The dealer has confirmed and inspected my vehicles condition, and Mazda customer experience has also review the matter after I provided the TSB and CSP11 information. Mazda has declined financial assistance because my vehicle falls outside the applicable coverage period and has stated that its decision is final. I am submitting this complaint because I believe this documented cylinder head failure may represent a significant safety/reliability concern for other CX-9 owners, particularly if the condition develops shortly after the 10 year /120, 000 mile coverage limit. I believe and should be made aware of the potential for coolant loss, overheating, and engine damage and that NHTSA should review the scope and safety implications of this condition.

The liftgate (trunk) opens sporadically. The system keeps trying to open the truck and it's causing a parasitic drain on my battery. I was stranded 2 hours from my home due to this. My trunk would sporadically beep three times, that is the only warning I received. There are safety recalls for other year of Mazda cx-9 but not my specific even though I am having the same issue.

Passenger seat heater either had a grounding issue or shorted out, causing to seat to start smoldering and catching fire, destroying the seat. There has been recalls and lawsuits for this specific issue on this model in other years, but not for this model year.

My 2018 Mazda CX-9 with the SKYACTIV-G 2.5T engine has been diagnosed with a cracked cylinder head, cracked exhaust manifold, and cracked turbocharger at approximately 88,000 miles. This is a known design defect documented in Mazda TSB 01-002/23 and addressed by Customer Service Program CSP11, which extended the powertrain warranty to 10 years/120,000 miles for coolant leaks at the cylinder head. The TSB identifies exhaust manifold deformation and residual production stress as root causes of the cylinder head cracking. In my vehicle, the failure has extended to the exhaust manifold and turbocharger, both directly mounted to the cylinder head in the same high-stress zone. The turbocharger on this engine is a coolant-cooled unit. As coolant leaks from the cracked cylinder head, the turbocharger is deprived of its cooling supply, leading to excessive heat buildup and eventual cracking of the turbo housing. The turbo damage is a direct consequence of the cylinder head defect Mazda has already acknowledged. CSP11 covers the cylinder head but does not address consequential damage to the exhaust manifold and turbocharger caused by the same defect. I am requesting the NHTSA investigate whether Mazda's remedy is sufficient and whether a formal recall is warranted given the risk of sudden engine failure at highway speeds.

my 2018 MAZDA CX-9 safety issue SCBS / SBS, LAS / LDWS, MASTER AND/OR HBC WARNING LIGHTS Forward sensing camera (FSC) stops functioning cause my car run rough even depress accelration and those light came on dashbaord -Forworad smart city brake support malfunction -smart brake system -front camera sensor malfunction

My 2018 Mazda CX-9 experienced catastrophic engine damage after a radiator failure allowed coolant to enter the engine. The vehicle provided no dashboard warning, overheating alert, or coolant warning before the failure occurred. Modern vehicles are designed to alert drivers to overheating or cooling system failures. The lack of warning prevented me from addressing the issue and resulted in catastrophic engine damage. I believe this represents a potential safety defect in the vehicle’s cooling system monitoring and warning system.

my 2018 MAZDA CX-9 safety issue SCBS / SBS, LAS / LDWS, MASTER AND/OR HBC WARNING LIGHTS Forward sensing camera (FSC) stops functioning cause my car run rough even depress accelration and those light came on dashbaord -Forworad smart city brake support malfunction -smart brake system -front camera sensor malfunction

- My 2018 Mazda CX 9 started stalling and jittering at idle and then eventually during slow driving. - Next day I got a check engine light, took to Mazda service center at the dealership I have been going to for last 6 years since I bought the car. - Service center diagnosed that there was a coolant leak through the cylinder head which seems to have cracked. - Further investigation indicated that this has been identified on many other similar Mazda engines and a Technical Service Bulletin had been issued by Mazda to Dealers. - On probing initially, dealership declined they were aware of any such problem. - The amount of repair for the engine replacement (cylinder head and other parts) is exuberant and is almost half of the value of my car, and is not expected for a low 44,000 miles car. - This had posed safety issue for my family since the stressed engine with leak in cylinder head could lead to fire and fatality. - I am awaiting response from Dealership and Mazda corporation case#[XXX] for a response especially when this issue has been filed under a class action lawsuit: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Mazda has a known technical service bulletin [XXX] which has numerous engine cylinder heads which leaks coolant causing the engine to overheat without warning. On new cars. Mazda knows it’s an issue and has not pushed this information down to its consumers. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

[XXX] 2018 MAZDA CX-9 GRAND TOURING 89014 MILES Date: 9/11/2025 To: Mazda North American Operations Attn: Customer Experience Center 7755 Irvine Center Drive Irvine, CA 92618 USA Subject: Formal Complaint Regarding Safety and Technical Issue – 2018 Mazda CX-9 Dear Mazda Customer Experience Team, I am writing to formally lodge a complaint regarding a serious safety and technical issue I have experienced with my 2018 Mazda CX-9. After a recent inspection conducted by Mazda Koch 33, it was brought to my attention that the engine wiring harness is defective and may potentially cause a fire or result in burns, posing a severe safety risk to me, my passengers, and others on the road. This issue is deeply concerning and unacceptable, especially considering Mazda’s reputation for reliability and safety. A fault in the engine wiring harness, particularly one that has the potential to ignite or burn, should be treated with the utmost urgency. It is troubling that such a critical component could present such danger. My vehicle has been serviced and maintained regularly, and I was not made aware of any recall or technical service bulletin that addressed this defect until the inspection. Given the nature of the defect, I believe this may be a manufacturer defect, and I request that Mazda: Immediately investigate and confirm whether this issue falls under an existing recall or known defect. Take full responsibility for replacing or repairing the affected wiring harness at no cost to me. Provide assurances in writing that my vehicle is safe to operate. Offer compensation or a loaner vehicle if the repair process renders my vehicle unusable for any period of time. Please consider this a formal request for immediate corrective action. I expect a prompt response within 10 business days of the date of this letter. If I do not receive a satisfactory resolution, I will be compelled to escalate this matter further through consumer protection agencies, such as the INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATI

I am submitting this recall request because my vehicle has experienced repeated incidents of a serious safety issue. While driving—most often on the highway—a warning appears that says “Smart System Brake Malfunction.” Immediately after, the car begins braking on its own without driver input. This has happened multiple times and, based on online reports, it appears to be affecting many Mazda vehicles across different models and years. Each time, I have been forced to pull over, turn off the car, and restart it to temporarily resolve the issue. This is extremely dangerous, especially at highway speeds, as it creates a high risk of rear-end collisions and sudden loss of vehicle control. When reported to Mazda, the concern was dismissed as a “sensor issue,” but the repeated nature and widespread reports suggest a potential systemic defect that requires urgent investigation and recall.

Passenger side sun visor will not stay in place. Cannot lock it in up position, which means it droops. Causing sight of vision impairment.

My sunroof exploded while driving.

Steering makes knocking noises when turning. It happened suddenly with no damage to car to cause it. It was fine prior to parking, when the car was restarted and the wheel was turned knocking noise started. Mechanic found there is a tsb for this problem but no recall.

the cars engine makes loud rattling noise and slips gear. the vecicle jerks hard and feels as if transmission is slipping. car hesitates when i shift into gear, followed by a jerking and jolting into gear. my brakes are replaced frequently. mazda at 65643 miles on car found excess operating noise coming from engine coolant/water pump due to internal bearing failing. they replaced the water pump. software (pyd8-18881-f) replaced. the vehicle has 74000 miles and has same problem. when stopped at a traffic signal it lunges forward at times. and shifts slow to fast gears. this problem is not resolved. the first time it was allegidely fixed was 22Dec2021 it is now 05Oct 2022

My passenger heated seats malfunction while I was driving. As I was driving on the highway I smelled something burning. I didn't know where the smell was coming from it was strong . Then while I'm driving on the highway my seat started to smoke a lot I got scared and pulled on side of the road. I realized my seat was the issue turned off the heated seats on the control. Step out the vehicle on side the highway I was nervous and scared standing outside my vehicle. The smoke eventually died down and cleared out. I never turned it back on and put a small piece of tape over the hole it burned through my seat.

The adjustable rails holding the rear left seat in place no longer latch. It is available for inspection. This is the most common place for a car seat in this car. In the event of a crash the seat would slide forward. The seat belt attaches to the seat so there would be little restraint on the rear passenger. The mechanic who attempted a repair stated Mazda does not sell this part, only sells a replacement for the entire seat, about $5000. There were no symptoms, when adjusting the seat the rail just stopped holding the seat firmly in place when the adjusting bar was released.

I'M CONSTANTLY HAVE A FRONT WINDSHIELD ERROR : CAUSING MY VEHICLE TO JUST AUTOMATICALLY STOPING WHILE DRIVING ON THE FREEWAY AND STREETS. MY AIR BAGS DIDN'T DEPLOY WHEN I WAS I A ACCIDENT . I'VE TAKEN IT TO THE DEALER 3 TIMES ALREADY AND THEY ALWAYS HAVE A DIFFERENT EXCUSE OR REASON

TAKATA RECALL - WAS IN A HEAD ON COLLISION WITH 3 OTHER CARS INVOLVED, ALL CARS WERE TOTALED AND ALL OF THE OTHER CARS' AIRBAGS DEPLOYED WITH THE EXCEPTION OF MINE AND I WAS INJURED AS A RESULT.

The seat belt in the center seat of the middle row of seats is locked in unusable position.

CPSC: THE MANUFACTURER SELLS A SMART CAR SEAT. *DT THE CONSUMER STATED THE CYBEX SIRONSAFE 2.0 CAR SEATS PLUG INTO THE VEHICLES OBD PORTS. THE CAR SEATS BOTH INDIVIDUALLY DRAINED THE BATTERY OF THE VEHICLE. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE BUT, DID NOT OFFER ANY ASSISTANCE. *JS

I keep getting a automatic emergency braking malfunction alert

While I have not been involved in an accident yet, I have discovered an issue that is believed to be the same issue that other models are covered under a recall, yet for some reason my VIN is not included. The bulleting reference number is 02-001/20 that covers MAZDA 2016-2020 CX-9 models. I have a 2018 CX-9 touring that is exhibiting the exact action of the recall which is "creaking noise from front lower arm bushing/clunking noise from front shock absorber coil spring when driving over bumps". It is only getting worse as time goes on. I am confused as to why some vehicles would be included in this recall yet my year model is experiencing the same issues but is not covered under the recall. I don't know if people are not reporting it, which is why I am filling out this report today.

While driving the rear wheel trim piece went flying off and struck the car behind. Noting was loose, showed signs or issues beforehand and nothing was struck on the road. Online searching has shown this is an issue others have experienced.