NHTSA Owner Complaint Log
This page lists owner-reported complaints filed with NHTSA for the 2018 Mazda CX-9. Complaints are unverified consumer reports submitted to NHTSA and do not by themselves prove a defect or defect rate.
Data synced from NHTSA on May 4, 2026
Coolant leak not from radiator but from the engine
Just noticed coolant leak during oil change. Vehicle has 77,000 miles. Power train warranty is only to 60K. The vehicle is undriveable without major engine work or engine replacement.
Car started idling rough and losing power at 135000 miles. Then started to overheat. Mechanic noticed coolant was low and added some. Problem continued to get worse and now engine won’t turn over. Mechanic said it was a cracked head leaking coolant into engine and it’s a known problem with the CX-9.
The cylinder head cracked and leaked engine coolant at 72K miles. This is a known design flaw IAW TSB 01-007/22. Vehicle overheated.
Engine coolant leaks at cylinder heads I started noticing the problem at around 50000 miles its a small coolant leak but car is almost 6 years old and now 54000 miles
Coolant leak from casting defect. Common issue.
Cracked cylinder head which lead to coolant leak.
The contact owns a 2018 Mazda CX-9. The contact stated that while the vehicle was parked, he noticed an abnormal odor inside the vehicle. Upon inspecting the vehicle, the contact found a trail of coolant. The vehicle was taken to an independent mechanic, who confirmed that coolant was leaking, and referred the contact to the dealer for a diagnostic test. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 88,080.
GPS touchscreen developed cracks described as inside-frosting or spide-web. Mazda had a recall for 2015-17 years models for the same problem, but they are reluctant to recall 2018 models. In 2019, Mazda discontinued selling touch-screen GPS, but it refused to extend recall for 2018 models. I took my car to the dealership and the cost of repair is $2400. The dealer did not find any damage caused by external force. Hence, this is the same recall issue with poor hardware and craftsmanship. I would like to ask NHTSA to compel Mazda to do a recall for CX9 2018 GPS touchscreen.
Driving on a major highway, when the engine overheating temperature light appeared on the instrument cluster. Seconds later it appeared and felt as if the engine would seize and come to an abrupt halt in the middle of a major highway. Thankfully I was able to quickly find a place with room to pull over, avoiding a potential collision. The engine coolant abruptly leaked/exited from the vehicle. I believe there is a service bulletin (No.- 01-002/23), but still no signs of a Recall being issued in reference to this safety concern.
The vehicle started leaking coolant, I had it towed to dealer to prevent further damage. They said it has a cracked head, which is a known issue with the 2016-2019 Mazda's, and is acknowledged by Mazda to be their fault. They have posted on a service bulletin that it was caused by added stress during manufacturing. Like many others, they want me to pay over 8k dollars for the repair. This is ridiculous as Mazda has stated that it is their fault.
There is a recall for Mazda 2016-2017 infotainment screens where they will show signs of cracking under the plastic and the screen will reboot. I have a 2018 CX-9 and Mazda corporate acknowledged the issue but only offered 15% of the price of a replacement part instead of replacing it. They said my VIN was not part of the original recall. I informed them this was a safety concern and then did not care. Case number - [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Started smelling coolant through AC and noticing that temp would momentarily spike to 240 before going back down to 200. My independent mechanic diagnosed it as a coolant leak in the cylinder head related to Mazda Tech Service Bulletin 01-002/23 (https://www.tsbsearch.com/Mazda/01-002-23). Took it to Mazda dealership, they confirmed a coolant leak and wish to replace the whole engine. Problem is that vehicle 1) has 105K miles and is not under warranty 2) Mazda engines are on back order and may not be available until November. I am going through an appeal process with Mazda right now to try to get some relief from a 9K repair bill. Disappointed that this known issue ( several threads in the Mazda forums ) is not getting the attention from Mazda that it deserves.
A coolant leak appeared around 62,000 miles. Car started overheating and come to find that I had no more coolant left in the reservoir. I filled it back up and drove it to the mechanic, after almost a week in the shop and have been quoted over $2k for the fix. There is a TSB out on this issue. It is a known issue apparently from a casting defect in the heads / block.
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.
My sunroof exploded while driving.
I noticed my 2018 mazda cx9 Sweet smell coming out of the engine.. When we were driving, a memo came up on my car screen and says please turn off vehicle as soon as possible, overheating. I was Scared That my car could have stopped in the middle of the freeway with my kids in it. My current was low. My engine was really hot and so we took it in to Mazda dealer. They diagnosed my car, and they said it had a cracked cylinder head by the exhaust manifold and because of that, it overheated my engine. This is a manufacturer problem. And it could have harmed my family. Mazda now doesn't wants to help me fix my this car, even when admitting they are fully aware of it. This happening on a freeway would have caused a major accident. There are Technical service bulletin on this case but people are Still in danger.
coolant leaks at the cylinder head around the exhaust manifold , safety was compromised by car overheating in the middle of extremely high level traffic, problem confirmed by Mazda dealership, only inspected by dealership, there was no warning indicators from the vehicle. I could smell antifreeze the day before it overheated.
A coolant leak appeared around 60,000 miles. I caught it in the right time as I had no more coolant left in the reservoir. I filled it back up and drove it to the Mazda dealership - I did not overheat at all so no warning lamps appeared. Upon taking it into the Mazda dealership, the engine was pulled and it was discovered that the cylinder head was cracked. This requires a new engine. There is a TSB out on this issue. It is a known issue apparently from a casting defect in the heads / block.
Sorry there was no incident
Engine cylinder head cracks open due to bad design where turbo puts too much weight and vibration resukting in coolant leaking out of engine. Mazda has a bulletin out for this issue and I took it to a Mazda dealer for repair. They confirmed this was the issue.
Bought car new in 2018. At 72,600 observed coolant leaking from backside of motor. Carried to Classic Mazda of Texarkana,TX for diagnostic test. Has a cracked cylinder head.Mazda refused to pay to fix or assume any responsibility for the design flaw. Turbo charger is too close to the cylinder head causing heat issues over time resulting in cracked head/coolant leak.
A known faulty cylinder head in these cars is breaking. A simple search of the web shows numerous owners have had the same problem. Mazda dealers KNOW it is a problem. They have upgraded the part, but it comes at a cost of approximately $7800 to owners of said vehicles.
The vehicle has a cracked cylinder head as a result of stress put on the block from a bad exhaust manifold design. This is a known issue to Mazda and service bulletin was sent out to all their dealerships in 2021. Mazda only offered to pay a very small portion of the repair and puts the rest of the cost on the customer. Luckily I caught the issue early but this could have been dangerous if the car overheated and the engine failed on the highway. There are countless other stories of consumers having the same issue with the CX-9 and CX-5 of the same year. Many resulting in engine failure.
I own a 2018 Mazda CX – 9 with only 53,300 miles. I noticed something was wrong with my engine and had no idea what the issue was. My car would not shut off immediately when I turned it off and the fan was on super high speed. The day before my appointment with my mechanic, the engine light turned on. I was stuck in a parking lot and a friend suggested I use his car to go buy coolant just in case it was needed. Sure enough, I was completely out of coolant. When my mechanic inspected the car he told me I had a coolant leak and suggested I take it to the dealer as they would know immediately what the problem was. I started researching to see if this was a defect and sure enough, Mazda has been aware of the defect with the cylinder head (TSB) not supporting the turbo of the engine causing it to crack and mix with the engine oil in various models for years, yet continue to sell cars with this known defect. I understand that it may not be life threatening yet! But it could have been should my engine had blown while I was on the freeway causing a horrific accident. How are they allowed to continue manufacturing and sell cars with a known issue for years and not even be reuqired to make a recall to have the part replaced with a stronger one? This is issue is happening to 100's of customers worldwide. This is something that should be investigated.
The main infotainment display randomly exhibited "spider cracking" which obstructs the view of the material being displayed within the screen. It is unsafe because the operator is unable to see maps, time, locations, controls, reverse cameras, etc. All of these are displayed in the screen and, due to the manufacturing defect, the operator is distracted by straining to see what is displayed behind the cracking. This is a well documented issue plaguing Mazda vehicles. Mazda has admitted it as defective, and are fixing the problem in the 2016-17 models. However, the 2018 model (which has the same screen as the 2016-17) is being refused. The fix needs to be extended to the 2018 model and beyond since it iw clear this it is still a widespread issue. It is well documented that once the cracking starts, it quickly spreads to the entire screen if not repaired, causing even more danger to the operator who will be distracted while attempting to see the display behind the screen.
This weekend Mazda CX-9 started leaking coolant from the firewall side.
The infotainment system screen has developed several cracks in the upper left-hand corner of the screen. Often time these cracks look like spiderwebs or frost --it's commonly referred to as "spider cracking." This is the second time my vehicle has had this issue. At the present time, the cracks are contained to the upper left-hand corner of the screen, but they are getting larger. The vehicle has been inspected by my local MAZDA dealership and I'm awaiting a resolution. As I understand, this is a known issue with 2016-2017 model years and a TSB has been issued for these years. MAZDA should extend the TSB to 2018 and beyond.
Coolant leak into cylinder head, resulting in overheating and blown head gasket. Repair cost was $7k to resurface cylinder head and replace gasket. Repair did not fix issue, likely due to unseen cracks or warping to cylinder head. Will require rework, likely entire engine replacement, as the defect cannot be corrected.
The contact owns a 2018 Mazda CX-9. The contact stated that while the vehicle was parked, he observed condensation under the vehicle. The vehicle was towed to an independent mechanic where it was diagnosed that the engine needed to be replaced. The vehicle was repaired but the failure persisted. The contact stated that while the vehicle was parked, he observed condensation under the engine compartment and on the top of the engine. The vehicle was taken to an independent mechanic where it was diagnosed that there was a crack in the cylinder head and that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 68,000.
Driving the car home from work, the engine temperature gauge started to go up high. I added coolant that same night. Went to the dealership for a check up. I was told the coolant was coming out from the back of the engine and will need to partial repair the engine. Only 75k miles in the engine and that was an estimate cause I could need a brand new engine. Now I’m stranded with out a car waiting for a response. MAZDA should do a recall regarding that issue cause I’ve seen a lot of CX9s have the same issue. THATS NOT GOOD FOR RELIABILITY.
Coolant leak at cylinder head. It is available for inspection. Driving on the highway and the car overheating light came on. Yes it has been reproduced and diagnosed as part of the TSB 01-013/21. No warnings, no notice of leaks before this happened. Noticed this in January - and thought it was just a one off and had the coolant topped off. Nothing happened until a month later that is when I took it to the mazda dealer. Safety issue as no one knows about it until their light comes on and they take it to the dealer to look at. Having this happen in the middle of nowhere on a highway with three small kids is a nightmare. This issue needs to be investigated. It is definitely a safety issue. It is shocking to know that Mazda has known about this for a couple years now based on the date of the TSB. A letter, at the very least, should have been sent out to all owners. Instead they let us all sit with a ticking time bomb that will be cost prohibitive to fix.
I was resting my foot on my brake in the middle of sealed traffic and when I eased up to move forward when traffic my brakes did stop causing me to bump the car ahead of me. After that what came next was that my car then accelerated forward with my foot still on the brake. By then 2 other vehicles were involved in this accident. My car is now totaled from this.
I keep getting a automatic emergency braking malfunction alert
Infotainment screen (LCD) of Mazda CX-9 2018 has developed what looks like discoloration/scratching/frost in corner of screen about 2 years ago and it is continuing to spread over last 6 months. This screen is used for hands-free bluetooth/calling (which is now the law in Iowa) and the back-up camera which allows for safe backing. If screen is unreadable, these safety functions cannot be performed properly. I take my car into Mazda dealership for maintenance/oil changes and it has never been addressed as an issue, but I'm concerned.
After owning this used vehicle for about 11 months, the engine temperature gauge indicated the car was running hot - about 240 degrees. After inspecting the vehicle at home, we added coolant to the system. This helped maintain engine temperature temporarily, but we noted over the next several weeks that the coolant was dropping rapidly. After inspection by a Mazda dealer, it was concluded that the cylinder head needed replacing.
I have a 2018 Mazda CX-9 with about 66,000 miles. I noticed a coolant leak when my SUV sat in my driveway. It was there each night after driving the SUV. I took the vehicle to a Mazda dealer who stated that the coolant leak is from a cracked cylinder head. A cylinder head should not crack in 4 years and only 66,000 miles. This is a known Mazda issue for this year make and model.
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
I noticed a smell of antifreeze. After taking it back to dealership, I find out it has a cracked head. It has never ran hot.
I purchased my 2018 Mazda CX-9 Grand Touring CPO with 39k miles and was sold the life time extended powertrain warranty through the dealership. The car now has 74k miles. While sitting idle at the school bus stop in my neighborhood waiting for my daughter the temperature gauge light comes on. I immediately drive home (exactly 0.3 miles) not going over 10mph back home, park call a tow truck company to tow it to the Priority Mazda dealership in Tysons Corner, VA from which I bought it. After a few days the mechanic calls and tells me there is a coolant leak and the repairs for the Cylinder Head should be covered under my lifetime extended warranty. A few days later I get a text message from the service rep that states. "Unfortunately, the extended warranty has denied coverage of the Cylinder Head, stating it to not be an internally lubricated issue....we need to fully inspect to determine what is needed (cylinder head or full engine due to overheating) Cost of teardown $1,432." After speaking to the service rep directly he then tells me the coverage was actually denied because Mazda put out a TSB on this known issue which voided my extended warranty on the cylinder head. This TSB bulletin no.01-007/22 was just issued 2 months before this happened. We should not be responsible for a known engine issue on Mazda's flagship car after purchasing an extended warranty for this very reason.
While commuting home on 8/19/22 my CX-9 began overheating and coolant temp. warning light illuminated on dash. This was a dangerous situation as I had to stop in the middle of traffic for fear of ruining my car and risk getting rear-ended and also navigate to the shoulder of the road. Took the car to the dealership where they confirmed P111A engine overheated DTC and coolant leak. CX-9 has a cracked cylinder head, the exact problem outlined in Mazda TSB 01-013/21. This happened at 61,xxx miles...roughly 1,000 miles outside the powertrain warranty however it's highly likely this crack and leak developed well before the end of the powertrain warranty period.
After sitting in the heat of summer, cracks appeared on two of the corners of the LCD navigation screen making it very hard to see portions of the screen.
The cylinder head failed causing a massive leak of engine coolant. This occurred initially at highway speeds which caused potential danger to myself and others around me as the car was required to pull over immediately. The problem was confirmed by the dealer and is known to the manufacturer as indicated by TSBs. The part was inspected and replaced by a new, redesigned part at the owner's expense.
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.
Car starting misfiring . I was told it appears to have a crack in the head gasket & would be best to repair the engine . This car has only 80k miles and should NOT be doing this at this stage!!!
When this vehicle is low on fuel (but not empty) and under heavy acceleration, the fuel pump temporarily fails causing the engine to stall. This creates a serious safety hazard. Other 2019 Mazda models were covered for a similar defect under NHTSA Campaign Number 21V-875, however this specific VIN is questionably not included under that recall.
the Mazda Connect information screen has small spider cracks on the upper right part of screen that are inside the glass (if you run your finger over the crack it feels smooth). Information websites pertaining to Mazda vehicles say it's caused by temperature change.
The contact owns a 2018 Mazda CX-9. The contact stated that while pulling up to a gas pump the vehicle lost motive power and stalled. The contact added gasoline to the vehicle, restarted the vehicle, and was able to continue to drive to her residence. Several weeks later the failure recurred while the contact was pulling into a parking lot. The check engine warning light illuminated. The contact’s husband arrived at the scene and added gasoline to the vehicle. The vehicle was restarted however, the check engine warning light remained illuminated. The vehicle was taken to the local dealer to be diagnosed. The contact was informed that the fuel pump and sensor were faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 65,000.
had loss of coolant mid to late January 2022, which lead to over heating notifications. Upon inspection at dealer (Pacifico Mazda Philadelphia PA), it was determined that i had a cracked cylinder head. Initially dealer said they were to replace just the cylinder head & after about 1 week they said that the engine would be replaced. Received car back 4/06/22
The contact owns a 2018 Mazda CX-9, The contact received notification of NHTSA Campaign Number: 21V875000 (Gasoline, Fuel System) 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.