Cylinder head crack/failure required the replacement of the entire engine on my 2016 Mazda cx9, the odometer was only at 85,000km. The crack Resulted in loss of coolant and overheating, the indicator on dash stating to pull over and shut the car off. This could have resulted in engine seizing if I was unable to safely pull over. This is a know issue by Mazda, the dealership has seen this issue before, there is lots of documentation online for this as well. There has since been updated parts to repair this issue, This should be a recall covered by Mazda. No car should require an entire engine replacement at 85,000km. This repair cost me $7700 out of pocket.

- Aldergrove, WA, USA

First radiator blew (after noticing the temp gauge higher than normal and fan running a lot), and when replaced, the 2016 Mazda CX-9 continued to leak coolant. Took it to dealership to find out engine cylinder cracked and head gasket. A simple google search finds that so many Turbo Mazda-??s between the years of 2016-20 experienced this design flaw as well. Mazda would not cover any of it since the car was out of warranty. It costed me over $7,000 to repair radiator and engine.

- Carmichael, CA, USA

My 2016 Mazda CX-9 2.5l Touring has approx 67,500 miles. I noticed the "sweet" smell of coolant after driving. The temp gauge was not showing signs of overheating. I checked under the hood and coolant level in radiator and reserve tank were normal. I also did not see any coolant leak/patches under the car. Few days later the car temperature gauge shot past the 1/2 mark. i stopped the care let it cool and checked under hood. radiator was empty but reservoir tank was still full. there were signs of coolant drips underneath car on the plastic cover below the area of the water pump (passenger front wheel side). waiting to have car assessed/fixed by mechanic.

- Waybe, NJ, USA

While driving on the freeway in stop and go traffic the engine warning light came on. A few minutes later the data screen stated that I needed to pull over immediately as my engine was overheating. I was on a stretch of the 5 freeway north of Oceanside with no exits for several miles. I pulled over and when the light went off I got back on the freeway to try to make it to an exit. I repeated this process until I was able to exit and pulled in at the first mechanic I came to. The vehicle was losing power at that point. Pulling in and out of the traffic was hazardous to both me and the other drivers. When they inspected my car, they determined that the coolant had been leaking for a significant period of time as demonstrated by the worn spot on the pipe it had landed on. Further inspection revealed a blown head gasket. When a new head gasket was ordered from the local Mazda dealership, the mechanic was surprised to learn that Mazda had four of these parts in stock as most dealerships would have to order the part. The Mazda service department told him that they had four head gaskets in stock because this happens pretty often. My research on this site and on the Mazda forum indicates that this is a known defect to Mazda. This vehicle has just over 56,000 miles on it. It is regularly serviced. There was no warning light prior to this incident, in fact, the blue light indicating the engine was cool had regularly appeared whenever I started the vehicle. I have the replaced head gasket in my possession, should inspection of the part be necessary. I have reported this issue to Mazda but have been advised it is unlikely they will reimburse me.

- Newport Beach, CA, USA

Head gasket blew in a 2016 Mazda CX9 while driving causing us to as safely as possible quickly get off the road from the middle lane of an interstate. This is from a known coolant leak in the cylinder head from service bulletin 01-013/21.

- Simpsonville, SC, USA

Car overheated. check front engine and could not see any visible leaks. check all around the engine and found coolant leaking from the back of the engine. confirm by dealer that is leaking at the cylinder head.

- San Antonio, TX, USA

My engine head cracked whiling driving. sudden lost of complete power in houston texas at a 75mph speed. Was able to safely pull to the side. took it to the dealer where they confirmed it was a cracked engine head. Its a common issue with this model from 2016-2019 no warning light came on just lost 90% power. was able to restart and drive the 7 mins to the dealer.

- Conroe, TX, USA

At an intersection the engine stalled and car was extremely hard to restart (took several minutes). I later noticed oil and coolant dripping from the engine and coolant mist/vapor from the exhaust. Later I learned it was possibly related to Mazda's own TSB Bulletin No: 01-013/21 where a manufacturing defect caused coolant to enter the combustion chamber and hydro lock the engine (where I stalled and had hard time restarting). I had to have the car towed home. At home I noticed the passenger underside of the vehicle coated with oily/watery residue of possible oil or oil/coolant mix. Vehicle had 66K miles on and Mazda dealer refused to fix.

- Myrtle Beach, SC, USA

I am being told by the dealership service center that there is a coolant leak from the engine. A previous coolant look due to a hose was repaired but this is a separate issue related to the TSB for coolant leak at the cylinder head Bulletin 01-007/22

- Indianapolis, IN, USA

Cracked Cylinder Head due to Coolant Leak - SB 01-013/21. This is a known issue with Mazda, yet it has happened with the vehicle being serviced regularly. This is happens directly after the warranty period and it is not being covered.

- Rosenberg, TX, USA

A strong coolant smell was noticed in the interior of the car and from the engine compartment. The diagnosis from the Mazda service facility was that there was coolant leaking from the head on the engine. Eventually this would have led to overheating of the vehicle which could have resulted in significant engine damage. The manufacturer has issued a technical service bulletin (TSB) for this problem. Cracking of the head that leads to coolant leaks is a known problem with this engine in several different models of Mazda including CX-5, CX-9, and Mazda 6. Our vehicle has remained in the shop since it was taken in on 11/8/2022.

- Bethesda, MD, USA

Due to Mazda's known problem in the design of their engine at just over 80,000 miles the head and turbo of my engine have cracked. They have issued a service bulletin to their dealerships, which acknowledges this as a common problem. (Technical Service Bulletins (TSBs) are official communications between Mazda & its dealerships that describe processes for troubleshooting or fixing certain common problems.) Unfortunately, for most Mazda CX-9 owners this bulletin was issued after most have just passed their 60,000-mile warranty, thus allowing them to get away with designing an engine for a fairly expensive car that is only good for 80,000 miles. Mazda further acknowledges this as a problem as newer engines are no longer designed the same way to avoid the problem and any parts put on the engines that are failing are of the new design because the OEM parts will just fail again. Dealing with Mazda customer service is a joke, they are rude, refuse to answer questions and will not call you back with answers when they say they will.

- Elkland , MO, USA

The cylinder head has cracked and it leaks antifreeze. This can cause the vehicle to overheat and destroy the engine. It is apparently a known issue as Mazda has issued 3 technical service bulletins addressing the problem. They have even redesigned a new part to replace the faulty one. In the TSB they even address that the crack may be caused by "stress generated during production" In other words, its a known problem yet they havent issued a recall on it. Im guessing they havent issued a recall because the quote for the repair was $5000. At $5000 to repair the faulty part it would be quite the expensive recall for the company.

- Blair, NE, USA

My Engine is over heading because it has a crack and losing coolant externally. There are 74773 mills on my car. Every 3 weeks I have to put a gallon of coolant in the engine. if I don't put coolant, the engine can stop working on the freeway causing bodily injury to me and other drivers.

- Rancho Mission Viejo, CA, USA

Engine Coolant Leaking from rear of engine near Exhaust / turbocharger at Cylinder Head. No Warning Lights indicating problem until coolant level low causing overheating and fire risk. Rear Brakes not releasing completely from "City Mode" where brakes are kept close to rotor "to increase braking response in City driving" - causes premature brake wear, warped brake rotors (reoccurs within 10K miles from new / replaced rotors) Front Bumper Fascia keeps coming loose at clips near headlights on both Driver and passenger side. Had replaced at dealership 3 times, but continues. Bumper coming loose and can obstruct headlights while moving around at highway speeds

- Queen Creek, AZ, USA

2016 cx9, after reviewing online. Known issue with coolent and engine cylinder. Water coolent leak to engine head. Dealer asking 75k to replace engine. Mazda refused to acknowledge the known issue.

- Sachse, TX, USA

On 04/21/22, I took my car to the dealer after noticing antifreeze on our garage floor and a burning smell. NO check engine lights had illuminated. They proceeded to tell me that there was a coolant leak from head/block and cavity leak (something about channel pressure). They also stated this was a casting flaw during manufacturing of the engine. They told me I needed a whole new engine for $8,479.97! Mazda corporate refused to replace the engine at their cost because I had 64,575 miles on it and it was out of powertrain warranty. I called them and asked to speak to a supervisor and never heard from them. I called on 4/26, 4/27, 4/28, 5/4, 5/5 (5 times), 6/9, & 6/20. I finally gave up agreed to pay $7,479.97 (the dealer gave me $1,000 off). I received the car back on 05/20 and it would not start later that day. They towed it back to Mazda and they replaced the crankshaft sensor that was damaged upon install of the new engine. I received it back again on 05/31 and later in the day, the check engine light came on and the automatic braking system engaged while I was driving (thankfully only 40 mph). I managed to pull over in a turn lane before the engine died. I was so thankful I did not make it onto the interstate I was about to enter! Mazda came and picked me up and later got my car. They could not figure out why it was dying and finally got it to recreate it. They replaced another engine sensor and then drove it a lot to make sure it was truly fixed. I finally received my vehicle back on 07/07. I am afraid to take my car out of town and it makes me nervous it will die and automatically start braking again. They KNOW this is a manufacturer issue and they refuse to take responsibility. I am so disappointed in them. This is a huge safety issue. I am also lucky I didn't blow a head gasket before I took it into the shop the first time.

- Knoxville, TN, USA

Traveling on the highway going on a road trip. Had vehicle inspected prior and no fuel system problems were noted. I was going 75mph with my family when there was a coasting feeling in the car. I looked and my check engine light popped on and my car immediately would not accelerate and we quickly lost speed. By the grace of God were we able to pull over safely! Code P0132 was the engine code and after an hour, the engine light went back off and we were able to keep a safe speed traveling home. After speaking with a mechanic and dealership, I learned that this was a common problem with the Denso fuel system. My vehicle was not included in a recent recall that included a different year of my vehicle. If manufacturers are aware that a major defect is out there, how many people have to have an accident or potentially cause a huge accident because a car made 2 years prior with the same part from the same manufacturer has the same dangerous problem? It-??s ridiculous and I hope you look at this near fatal issue that has effected thousands of people, whose vehicles-?? were made in 2017, 2016, 2015 and are not included in the recall.

- Katy, TX, USA

I droved my 2016 cx-9 off highway and idled it at front of restaurant, suddenly the engine coolant overheat light came on, shut engine off and found leaking coolant on the ground near the rear of engine bay. Brought the car to Corpus Christi Mazda, found out leaks come from cylinder head crack, happens to cx-9 manufactured before June 20, 2020 according to Mazda TSB 01-013/21. I was quoted $3380 to replace the cylinder head out of pocket because the car is just out of powertrain warranty. I contacted Mazda headquarter for covering the cost out of goodwill since this is due to manufacture defects of cylinder head. Mazda refused to pay.

- Corpus Christi, TX, USA

Cracked cylinder head due to manufacturing defect, left stranded at car wash with no engine coolant due to issue, took several months without a vehicle before it was replaced by Mazda. The vehicle has been repaired. I was left unable to drive in hot weather and could not use air conditioning while waiting for assistance. Dealer had seen the issue before, reported by many on online Mazda forums. There were no warning lamps prior to the incident happening.

- Goshen, KY, USA