Driving home the car said 26 miles to E. while in gear going down the road it popped engine system malfunction and the whole car shut off and wouldn't start. Didn't drive the vehicle for 2 days- filled the gas tank and it drove fine for 5 days. Day 6- 4/8/2023, fine driving down the highway 45 minutes. Go down about a mile and it still doesn't seem right, I move lanes and the thermostat light starts flashing at 260, as soon as I make the turn it tells me to pull over and turn the car off-it was at 270. Go to drive across the street to get coolant later- car stalls when I shift into drive. Park it- get coolant takes an entire jug. Idling a little rough, but not bad. Mechanic he can't see any issues, computer is throwing out fuel system codes but no, issues that can be found. Does a tune up on it, pick it up. Smoking when I start the car and something smells burning. Driving home, it stalls again while in gar at a red light. RPM jumping between 500 and 750 while in gear. Park it for a few hours- everything seems fine. Drive 35 minutes- mostly highway. RPM isn't moving when in park vs neutral. While at last red light before home- engine system malfunction comes on. Driving a few miles down the road still on, temperature at 200. Drive about half a mile down the road- at 260 as I'm pulling into my driveway. Towed to Mazda the next day. Got diagnosis that the head lifted and coolant mixed into oil, flooding engine. Need a new engine and turbo- $10,000 to fix it. Never had issues prior and no signs of anything going wrong. Oil change done 2 weeks prior to this all starting.

- Fellsmere, FL, USA

Known engineering flaw that causes cylinder head to crack and leak coolant. Mazda will not do a recall even though numerous people are requiring new motors with no previous issues or warning lights on the car.

- Bastrop, TX, USA

While driving, my engine suddenly and dramatically lost power while a temperature warning appeared. I barely made it to a safe spot to park. After having it towed to the local Mazda dealer, the problem was cracks in the cylinder head. This is a known defect from Mazda, which has issued a TSB to dealers but has taken no proactive measures to protect owners. Just 5.5 years into ownership and 51,000 miles, I now must pay for a replacement outside of warranty, costing me over $9,000. All for a dangerous defect that Mazda is aware of and refuses to issue a recall for.

- Huntsville, AL, USA

My vehicle has several issues related to a water pump failure in which the check engine light did not remain on. The vehicle began to over heat and slow down on the highway/ roads despite having my foot on the gas. My vehicle is now at Heritage Mazda Catonsville and unable to be read by the OBD reader which may be related to a weak wiring harness reported by other owners of the CX9. It also my be why my check engine light is not on despite having an engine issue. Many others have reported a failed water pump which caused cracks in the head which causes the car to over heat and slow down without notice. Despite having thousands of customers with this issue Mazda has yet to issue a recall.

- Pikesville, MD, USA

Recently had my car into the local Madza dealer for oil change and break inspection. Soon after the oil change it started running rough. Then next thing I know it begins to overheat in the street at major intersection while driving home. Parked it let it cool down and then toed to Mazda dealer. Told antifreeze getting into the engine. I see Madza is aware of this issue and this engine is defective and can not handle turbo. I could have been killed at this very intersection so thankful I was safe. What if I was driving on the highway which I do every day this would have compromised many people's safety. This is a safety defect in that Mazda is knowing of this issue. The only warning was just as it happened. except it was riding a little rough at stops but no idea it was going to overheat. especially since it was just in the shop for the oil change. My car is still sitting at the dealer as they try to get warranty to cover. I could have been killed. When will something be done to protect the consumer.

- Raleigh, NC, USA

Coolant leak from a cracked cylinder head that mazda is aware of and released a TSB about. Refusing to extend warranty or fix due to being 6 months out of 60 month power train warranty. Still under 60,000 miles.

- Ephrata, PA, USA

This problem has been documented and know by Mazda for awhile. They are aware that their 2.5 Turbo liter engine has the problem of cracking the cylinder head due to some overweight of the same engine component. My Mazda local dealer already inspected the car and told me that the fix is replacing the whole cylinder head, which with them would cost me 3.5k. My warranty company, which I purchased when buying this used car, didn-€™t took responsibility of the repair cost because it was pre existing condition before I bought the car. Many people over the internet have reported this same issue happening to them, models year between 2016-2019. This issue cause a leaking of coolant. Which in my case has been a lot built up, to the point that you can grab it with your hands (the coolant residual).

- Harrisburg, PA, USA

Coolant leak. Cracked cylinder head in a stud hole of the exhaust manifold. 70,000 miles Seems to be a problem with many other owners.

- Springfield, MO, USA

The first sign of an issue was an oil pressure indicator on the dashboard, but upon inspection, the oil levels seemed completely normal. The dashboard light went away shortly after that. A day later, I was on my lunch break and parked my car in a garage for 45 minutes. On the drive there, I did not notice any issues and was able to operate the vehicle fine for the short distance that I drove. When I returned to my parked car, there was a large puddle of oil underneath. I immediately had a mechanic take a look at the car. The mechanic was able to identify a cracked cylinder head, which led to water and coolant entering the engine. He highly suspects that this caused a blown head gasket in the car as well. As well as that, the car's starter, which worked just fine on day 1 of the issue and has never had any problems before, has totally ceased function. If I had not noticed the oil pool underneath the car and driven back to work as usual, it could have caused the engine to seize and create a very dangerous situation for myself and others on the road, including but not limited to the potential of an engine fire with the level of oil lost. The car was up to date on its servicing, including oil changes. Two ASE certified mechanics have inspected the vehicle and confirmed the leaked fluids and aforementioned issues. No other professionals inspected the vehicle (insurance representatives, law enforcement, etc.).

- Los Angeles, CA, USA

Vehicle has only 50k miles and developed a coolant leak which was caused by a crack in the cylinder head. No check engine light or overheating, but this repair will cost was estimated as over $4k. A cracked cylinder head would eventually lead to vehicle overheating which can put driver and passengers in a dangerous situation if vehicle were to overheat while operating as this is a significant engine repair. After dealer technician inspected the part, I was informed that they don't see overheating or poor maintenance as the cause of this issue, but it was caused by the part failing.

- Broussard, LA, USA

Technician noticed coolant leak around turbo during routine maintenance. Sometimes after long drives we would smell hot coolant but didn't think it was an issue. Dealership took it in for repair under power train warranty and was advised that the engine needs to be replaced. From my understanding, the turbo is too heavy for the engine and has caused it to warp. The coolant leak is a symptom of a damaged engine block.

- Oceano, CA, USA

What component or system failed or malfunctioned, and is it available for inspection upon request" Cylinder head has cracked and the vehicle leaked coolant and overheated while driving leading to engine failure. Vehicle is available for inspection How was your safety or the safety of others put at risk? Car overheated while driving leading to engine failure Has the problem been reproduced or confirmed by a dealer or independent service center? Dealer has diagnosed the problem as a cracked cylinder head Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Yes, dealer has diagnosed issue and recommended replacement Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear" Engine temperature sensor went off and within seconds car was not driveable due to fluid loss

- West Sand Lake, NY, USA

Engine has serious manufacturing defects and a recall should recalled. The engine has casting issues which cause internal issues.

- Rocky Mount, NC, USA

2017 Mazda CX 9 signature engine failure at 89,000 miles. July 2021 check engine light came on, this was three months prior to failure. Was told it was a known computer issue and was charged over $200 to fix. November 2021 car started running hot while driving down the road. Red thermostat came on while driving. Was able to get the vehicle to the Mazda dealer that has done routine service on the vehicle. Was told it needed a new engine. Called Mazda customer service and was told it is a known issue with the turbo charge engine. This is a safety risk to myself and others because it could have gave out in traffic.

- Salisbury, MD, USA