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

I took my car into the dealership and was told that I had a cracked cylinder head and the car is leaking coolant near the rear of the engine. This could cause the engine to cease should coolant get into the engine. The dealer (North Park Mazda, San Antonio) has confirmed this as the issue. I have received a video of the inspection from the dealership explaining the issue. The vehicle displayed a warning that it was overheating which is what prompted me to bring the vehicle in for service.

- San Antonio, 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

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

Our head gasket is needing to be replaced and sounds like this is an apparent Mazda problem how wide spread it is. The cost is over $5,000 for this single repair, possibly over $6,000 if head is cracked. I only have a parts list showing $1,700 in parts. Service manager said about 18 hours at $189hr totalling $3,402.

- Wilderville, OR, USA

Driver stopped vehicle in a driveway with minimal slope, shifted the vehicle in park, turned off the vehicle and exited. Driver proceeded to rear passenger door to retrieve 1 year old from car seat. After retrieving child from car seat, driver felt rear passenger door pushing into her leg, back and head. Vehicle proceeds to roll out of the driveway backward while in park. Driver and child escape vehicle's rear passenger side door, which is pushing them along in the vehicle's path toward residential street. Vehicle continues rolling in park backward down residential street, through a 3-way stop intersection, up a curb, through a yard and into a bush on a private property. A witness who helped retrieve the vehicle on behalf of the driver noted the vehicle was still in park when he tried to remove it from the bush. No one was severely injured but driver has sustained bruising on leg and severe emotional distress.

- Oak Creek, WI, USA

The push button on/off switch does not protect against turning the vehicle off if transmission is accidentally left in any position other than 'P'. for example its possible to put the transmission in 'R' and turn the vehicle off. For a busy parent (target demographic of this vehicle), this is very dangerous. If on an incline, the vehicle will start rolling forward or backward (depending on incline/slope and R/D transmission position). There should be a safeguard or a beep/warn system to protect the driver/occupants this happened to me on an inclined driveway when I accidentally left transmission in 'R' and turned vehicle off. I took foot off the break and got out and realized vehicle was rolling backwards.

- Fremont, CA, USA