2017 MAZDA CX-9 Complaints

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.

While driving in normal, operating conditions, the engine cut off and had to pull off to the side of the road. After checking the OBD two error code from the check engine light, there was an error with the fuel pressure rail sensor. Apparently the fuel pump in these vehicles has been failing with regularity on many other models.