Owner-reported complaints naming the engine system, filed with NHTSA
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Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components. Every record below is an owner-reported complaint about the 2017 Mazda CX-9 submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 43 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
The 25 most recent of 43, in the owner's own words
this is covered under csp11. the problem is my car is a 2017 and they only allow a warranty up to 120,000 miles mine is at 158000 and they will not fix the problem now even thought we just started having problems.
I took our vehicle into Mazda due to a coolant leak that could not be located. It had my wife stranded due to the vehicle overheating. Everything lined up with CSP11. The dealership is now stating that the vehicle has a blown gasket and needs an engine replacement. This is the issue covered by CSP11 except that the crack is in the wrong location. They haven't found the Crack but are denying the warranty due to the covered location not being the source. The vehicle only has 93000 miles on it.
I was driving the vehicle on the highway when the vehicle started to overheat, lights started blinking, the car was smoking, losing power and acceleration. This car has a recall on the cyclindwr head which when cracks causing the car to loose coolant and oil. If it cracks while you’re driving especially on the highway the car will immediately loose coolant and oil thus causing a very dangerous driving condition. There was no indicator prior to the failure that there was anything wrong with the car. No check engine lights, no coolant lights nothing. Prior to this happening I smelled coolant in the car cabin , took it to my mechanic who tested the coolant system and found no leak. At the time he was unaware of the known issue these cars have with the cylinder head. The problem has been confirmed by Mazda and they notified me within the month of March of the problem and the extended warranty to replace the known manufacturer defect cylinder head. The Mazda dealer now has my car and acknowledges the cracked cylinder head caused the problem but said because I didn’t immediately stop on the highway and kept driving until I got to a safe location I was negligent and are refusing to fix the car which now has a blown engine, etc. it is available for inspection now at the Mazda dealer. My safety was put at risk because I could have died on the highway if the car completely stopped working, it was dangerous driving it when it first started happening because it started out of nowhere the car was fine I was driving 50+ mph and it started smoking, overheating etc. I could have also killed someone else. It is a disgrace that not only they won’t fix my car they want to say they won’t because I’m negligent? I drive my kids to and from school everyday do you think I’m going to risk their safety in an unsafe car? They should not only fix the car but compensate me for putting mine and my children’s lives at risk. A complete disgrace.
Vehicle experienced coolant leak also oil leak from rear of engine. Broken cylinder head due to turbo too close to head
My 2017 Mazda CX9 Signature Edition started leaking coolant from the engine near the firewall. I had a Mazda dealer investigate. They tell me the cylinder head is cracked and the entire engine needs replaced. This appears to be a common problem due to a design flaw and there is a Mazda service bulletin on it. I have found talk of a class action suit online because Mazda is not standing behind their product. I only have 88k miles on this car
My 2017 Mazda Cx9 was stalling and jerking while driving almost causing an accident but glad I was able to drive it home without causing an accident. Took the car to the dealership and was advised that it needs a new engine due to coolant leak. The coolant was going inside the vehicle.
The 2.5l turbo engine mounts are not manufactured strong enough to handle daily driving and torque under the weight of the turbo. This causing cracks in the block/head resulting in coolant leak, over heating, and full engine replacement.
July 10, 2024, antifreeze leaking from my engine leaking on garage floor. Yes, my safety was put at risk. July 12, 2024, local mechanic informs me that I have a cracked cylinder head coming from the back of the engine. July 15, 2024, vehicle will be towed to local Mazda dealership to have vehicle diagnosed. No warning lights, messages or any other symptoms of the problem prior to the failure. Happened July 10, 2024, at 3:50pm.
My Mazda 2017 CX 9 apparently had a coolant leak. When we had our oil changed, we were told it looked like it was leaking from behind the turbo booster. As I was driving it yesterday, the car slowed to an almost complete stop on the interstate and a warning sign on the screen showed that it was overheating to a dangerous level. I immediately pulled over and allowed the car to cool down. I checked the coolant level and it was not very low at all, although I did add some coolant at that time. It continued to overheat and even blew tons of smoke out through the exhaust, so I had AAA tow to my home. After researching this, I have found that there was a bulletin posted in 2021 from Mazda about this very thing happening. My husband thinks that we may have a cracked block or a blown head gasket due to this overheating. This obviously could have caused me to have a wreck on the interstate by my car overheating and shutting down so quickly. We are scheduling to have it towed to our local Mazda dealer to let him do the $99 diagnostic. Based on what he finds, which we think will be confirming what we think it is, we will have to have a new engine put in my car due to a defect in manufacturing from Mazda. Even though my car has 130,000 miles on it and is technically “out of warranty“, we feel this is simply unacceptable and that Mazda should help us with this most definitely. I have so enjoyed my Mazda, and I feel that this is not something of my doing, but rather a defect on Mazda part and it should be addressed.
This vehicle has been diagnosed as having the Cylinder Head Crack issue referenced in Mazda TSB 01-013/21. The car has just over 70,000 miles on it, so I understand it is out of Warranty, yet this issue only came up due to a known design flaw by Mazda. I have been told that I will be without the car for up to 9 weeks due to repair backlogs and the cost will be $5,250 plus tax!! This car has always been maintained at the Mazda dealership since purchase and has never had any other issues until this flaw, acknowledged by became an issue. Immediately, I brought it in, only to be told Mazda would not assist in a Good Faith repair. This is very sad that Mazda would do this to loyal customers, there should be a recall and this should not fall on customers pockets when we continue to give them business, trusting they would not knowingly put a full engine repair in their customers pockets
I noticed my 2017 CX-9 Touring was leaking coolant. It wasn't much but then checked the reservoir which is nearly empty. The car was overheating. I had it checked out by the dealer and initially I was told that it was bad radiator cap. This was fixed and resolved the initial overheating problems. The overheating issues resurfaced and took it a certified mechanic which indicated it was leaking from the engine block. The quote for repair was over $6000 See: Service Bulletin: 01-002/23
Engine head cracked and is still on car as of now. If engine overheats, engine can seize. The leak has been reproduced, but the head has not been removed for inspection yet. No warning lamps. A large puddle of coolant was noticed under the vehicle. From what I have heard is that the material is too thin and eventually cracks. There is a tsb that covers the issue, but since we've gone beyond the 5 yrs of the powertrain warranty it won't be covered. We are under the mileage limit. We lucky caught the leak before engine damage took place (as far as we know, since the teardown has not been performed. If the replacement head is "reinforcing" that area then a design flaw has been inferred and should be corrected to avoid serious injuries due to a seized motor.
My car has never had any issues but began burning through coolant. After analyzing myself and then bringing to a mechanic, it has a bad cylinder head leak. This is a design flaw in the motors of Mazda cars during the years of the models with a 2.5 Turbo motor. This flaw will now cost me over $6k for a car just out of warranty when I religiously serviced the car at the Mazda dealer I bought it at in 2017. I cannot afford these repairs that were cause by a design flaw on Mazdas side. There is a TSB and a class action lawsuit for this exact issue. Mazda should issue a recall or help owners pay for the repairs since they have acknowledged the issue but have not made it right.
I took my vehicle into the dealership service center to have maintenance and repairs done. I notified them to a coolant leak. They discovered that the engine has a cracked cylinder head and that the manufacturer is aware of the defect. They stated that they have new updated parts they will use for the repair so this will not happen again. At this time there is no Mazda warranty extension or recall that covers the cost of the repair.
There was a coolant leak on my Mazda CX9 Signature with a 2.5T engine, and when driving the engine temperature started increasing slightly before taking off and turning red. I had to pull off to the side of a busy interstate road very quickly and shut the vehicle down before it overheated any more. Once I got the vehicle to the dealership, they told me it was a cracked cylinder head leaking coolant, and that it was an extremely common problem for the 2.5T mazda engines around about 60k miles, and they were actively working on one in the shop where I was for the same problem. Mazda is not currently helping with engine swap or any repairs as a result and is sticking the customer with the bill.
Known issue in these CX-9’s. Had the issue fixed once with a brand new, Mazda, “redesigned engine.” 14 months and 30000 miles later it’s happening again. Leaking coolant due to cracked cylinder head. First repair was about 9 grand. This time my repair estimate since it’s premature was for another 6000 to replace the cylinder head versus the whole engine. That’s 15k on a used car when I could’ve almost paid it off with that amount at this point.
My car started leaking coolant around [XXX]. It did not gave me any alert the car was heating up. My eldest brother was the one that notices. I took the car to the dealership and they are telling me I need a new engine. Now I'm googling and I'm seeing a big number of people reporting same issue. The dealership refuses warranty because is up to 60k miles and mine has 72k miles. However many people are having same issue on where the metal in the cylinder head isn't strong enough to support the weight of the turbocharger. I'm seeing complain in the internet since 2016 and Mazda has done nothing to fix this issue. Please go to for reference: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
On 11/21/23 Mazda dealership informed that coolant leak in my Mazda CX-9 had ruined the engine. Research on the coolant leak has found several other cases in CX-9 models. It has been alleged that the engines in these vehicles may be prone to coolant leaks around the cylinder head and exhaust manifold joint due to excessive forces. When an engine coolant leak occurs, the vehicle may rapidly lose engine coolant and cause the engine to overheat. It has been further alleged that Mazda is aware of the engine coolant leak defect but has not extended the warranty or provided a redesigned part free of charge. As a result, consumers may be forced to pay for costly out-of-pocket engine repairs to correct the engine coolant leak defect.
Leak from cylinder head caused by overheating. Reported a coolant leak prior to diagnosis. Car now shows an over heat code. Safety was put at risk due to immediate need to pull over and no longer able to drive the vehicle. Dealership and initial shop had different diagnosis of the vehicle. Shop advised of a head gasket leak only. Only warning maintenance light came on as car began to overheat. No earlier notice other than coolant leak seen on ground.
I was driving to work with my daughter and my engine overheated out of nowhere and caused us to almost be rear ended
2017 Mazda CX-9 with crack in engine with coolant leaking out. Informed by mechanic that coolant was leaking out from the engine and was caught by heat shield. I smelled coolant, but never saw any on the ground. Per TSB 01-002/23 there is a crack that can develop in the engine due to stresses from the turbo/exhaust. A crack will develop near studs in the engine. Once crack develops, the coolant can leak out. However, in worst cases (which mine did not suffer from...yet), the coolant can leak into the engine and damage the internal components. Right now, I am looking at a $6254 repair bill to have a mechanic fix the engine. I will probably have to take this bill on as my family needs a second vehicle. Mazda needs to issue a recall that is the fault of their own, not the customer. This is occurring on too many vehicles, with turbos, from 2016-2020 CX-9s, CX-5s, and Mazda6s.
coolant leaks from cracked cylinder head which cause the car to overheat and have the engine stalled on the highway.
My car gave me a warning that it was overheating... and gave me a warning to pull to the side of the road because of safety and turn off my car engine because the engine is overheating. I was on the highway when this occurred. The engine coolant light was well into the red zone. I had my two kids in the car and my service animal... The car was say overheating and blinking the engine coolant red warning sign I brought the vehicle to a dealership and it was confirmed that my engine coolant was leaking behind the gasket head and is damaging the turbo charger. The same issue word for word that was stated in the TSB... Yes the warning sign of engine overheating and the engine coolant light to high flashing showed up on the vehicle and the warning of pulling over to a safe place to allow the car to cool down. I was on the interstate when the problem occurred. I also had to put coolant in the car because the reservoir was completely empty to take it to dealership for diagnostic assessment...I bought this car 6 months ago and it was running fine until 3 weeks ago. When the coolant continued to leak and the warning signs would not go away stating the engine was overheating. The repair for this known problem is astronomical and I'm wondering why Mazda has not sent a safety recall and why we are on the hook for the repairs when they know it's a manufacturer defect.
August 1, 2023, I discovered the coolant reservoir for my CX9 was empty, had to tow the car to the Mazda dealership, after a few days, the dealership informed me that I have a coolant leak at the cylinder head. This issue is related to the TSB #01-013-21-3753a. The Mazda dealership and Mazda USA informed me that I will have to pay $7,800.00 to have the car fixed, which is ridiculous, but the more serious part is that the car did not gave me any warnings, lights, overheating nothing. If it wasn't because I personally check the car fluid and didn't used the car afterwards, I could have hit the road and be left stranded in the heat or have an engine failure and cause an accident while on the highway.
I experienced coolant leaking from the cylinder head. Mazda is quoting me over $7700 for the repairs. There was a TSB released, there had been numerous revised versions re: the same issue, in Feb 2023 finally including my vehicle. Mazda knowingly put me and my family’s safety in jeopardy by not including me sooner, and now have left me with an astronomical repair bill for an issue they’ve known has existed for years. Had they alerted me when the originally discovered the issue, the vehicle would’ve been under warranty and they would’ve had to replace the parts under warranty.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
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