This Problem Across All Years
The vehicle will hesitate/stall while driving down the road. The vehicle has done this multiple times and has actually shut off on 2 different occasions while at a stop. on 2 occasions now the vehicle has not wanted to start. I have taken vehicle to Mazda dealership and they can never duplicate it. When they check for any codes, the vehicle computer does not give accurate times when happened. This last date I took it to them 6/9/25, the computer said it happened 4000 miles ago. The time before, I took it in the morning it happened, 5 min after it happened and the computer said it happened 10 starts ago. The last time, 6/9/25 they said they suspect fuel pump going bad, but until the vehicle gives a "check engine" light or dies all together they are not 100% sure. The vehicle is unsafe if it dies in the middle of the freeway/road with no warning to myself or the other vehicles around me. This has been going on for at least 1 year now, maybe longer Dealership has all records. Seeing how the 2018 & 2019 Mazda CX-9 had fuel pump recalls makes me wonder if the 2020 should have been included in this recall. This has been an on going problem.6/7/25 was most recent incident.
The vehicle will hesitate/stall while driving down the road. The vehicle has done this multiple times and has actually shut off on 2 different occasions while at a stop. on 2 occasions now the vehicle has not wanted to start. I have taken vehicle to Mazda dealership and they can never duplicate it. When they check for any codes, the vehicle computer does not give accurate times when happened. This last date I took it to them 6/9/25, the computer said it happened 4000 miles ago. The time before, I took it in the morning it happened, 5 min after it happened and the computer said it happened 10 starts ago. The last time, 6/9/25 they said they suspect fuel pump going bad, but until the vehicle gives a "check engine" light or dies all together they are not 100% sure. The vehicle is unsafe if it dies in the middle of the freeway/road with no warning to myself or the other vehicles around me. This has been going on for at least 1 year now, maybe longer Dealership has all records. Seeing how the 2018 & 2019 Mazda CX-9 had fuel pump recalls makes me wonder if the 2020 should have been included in this recall. This has been an on going problem.6/7/25 was most recent incident.
The vehicle was overheating and a message came up that power will be reduced. Then it would go away and come up every 3 minutes while driving. I brought it to the service center, we filled it up with coolant and the issue kept coming back this time with a lot of white smoke coming out at vehicle start up. My mechanic said this is a bigger issue most likely to do with a coolant leak at the cylinder head. There is a technical service bulletin but no recall as of yet.
The vehicle was overheating and a message came up that power will be reduced. Then it would go away and come up every 3 minutes while driving. I brought it to the service center, we filled it up with coolant and the issue kept coming back this time with a lot of white smoke coming out at vehicle start up. My mechanic said this is a bigger issue most likely to do with a coolant leak at the cylinder head. There is a technical service bulletin but no recall as of yet.
Excessive oil consumption. In less than 3000 miles, I have to add a quart of oil
Excessive oil consumption. In less than 3000 miles, I have to add a quart of oil
Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold. There may be cracks at the stud bolt hole or at the outside of the exhaust manifold - from Mazda's TSB. Excessive coolant leak leading to engine-overheating and going into 'limp mode' couldn't drive faster than around 30 mph. Mazda has repeatedly declined help with goodwill requests and any further assistance. ref. https: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold. There may be cracks at the stud bolt hole or at the outside of the exhaust manifold - from Mazda's TSB. Excessive coolant leak leading to engine-overheating and going into 'limp mode' couldn't drive faster than around 30 mph. Mazda has repeatedly declined help with goodwill requests and any further assistance. ref. https: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
THE MAZDA CX-9 UNCOMMANDED ENGINE ACCELERATION REPORTED HEREIN DID NOT RESULT IN ANY DAMAGE PRIMARILY BECAUSE IT COMMENCED SEVERAL SECONDS AFTER I BEGAN LIGHT BRAKING WHILE APPROACHING A RED TRAFFIC LIGHT. MY IMMEDIATE RESPONSE WAS TO INCREASE BRAKE PRESSURE; THERE WAS NO NEED FOR ME TO MOVE MY LEG OTHER THAN PRESSING HARDER WITH MY FOOT. MY FOOT HAD BEEN OFF THE ACCELERATOR FOR MANY SECONDS WHILE ALLOWING THE CAR TO SLOWLY DECELERATE WHILE COASTING TOWARD TRAFFIC STOPPED AT A RED LIGHT. WITHIN TWO SECONDS OF COMMENCEMENT OF UNCOMMANDED ENGINE ACCELERATION AND WITH THE CAR FULLY STOPPED, I SHIFTED THE TRANSMISSION INTO NEUTRAL. THE ENGINE IMMEDIATELY GENERATED THE NOISE OF VERY HIGH RPM. ALTHOUGH THE DASHBOARD INCLUDES A TACHOMETER, I DID NOT IMMEDIATELY THINK TO LOOK AT IT; INSTEAD, I TURNED THE IGNITION OFF. A FEW SECONDS LATER, I SHIFTED THE TRANSMISSION INTO PARK AND RESTARTED THE CAR WHICH OPERATED NORMALLY THEREAFTER. MY FOOT DID NOT MOVE OFF THE BRAKE PEDAL DURING ANY OF THE PRECEDING SEQUENCE. ONLY THE NHTSA AND POSSIBLY THE MANUFACTURER WOULD KNOW IF THIS IS A ONE IN A BILLION-HOURS OR A MORE COMMON OCCURRENCE. I AM WILLING TO ANSWER ANY QUESTIONS THE NHTSA OR THE MANUFACTURER MIGHT HAVE. I GRADUATED FROM MIT, WORKED OVER 29 YEARS FOR THE LEADING USA COMMERCIAL AIRCRAFT MANUFACTURER AND AM CURRENTLY RETIRED.
THE MAZDA CX-9 UNCOMMANDED ENGINE ACCELERATION REPORTED HEREIN DID NOT RESULT IN ANY DAMAGE PRIMARILY BECAUSE IT COMMENCED SEVERAL SECONDS AFTER I BEGAN LIGHT BRAKING WHILE APPROACHING A RED TRAFFIC LIGHT. MY IMMEDIATE RESPONSE WAS TO INCREASE BRAKE PRESSURE; THERE WAS NO NEED FOR ME TO MOVE MY LEG OTHER THAN PRESSING HARDER WITH MY FOOT. MY FOOT HAD BEEN OFF THE ACCELERATOR FOR MANY SECONDS WHILE ALLOWING THE CAR TO SLOWLY DECELERATE WHILE COASTING TOWARD TRAFFIC STOPPED AT A RED LIGHT. WITHIN TWO SECONDS OF COMMENCEMENT OF UNCOMMANDED ENGINE ACCELERATION AND WITH THE CAR FULLY STOPPED, I SHIFTED THE TRANSMISSION INTO NEUTRAL. THE ENGINE IMMEDIATELY GENERATED THE NOISE OF VERY HIGH RPM. ALTHOUGH THE DASHBOARD INCLUDES A TACHOMETER, I DID NOT IMMEDIATELY THINK TO LOOK AT IT; INSTEAD, I TURNED THE IGNITION OFF. A FEW SECONDS LATER, I SHIFTED THE TRANSMISSION INTO PARK AND RESTARTED THE CAR WHICH OPERATED NORMALLY THEREAFTER. MY FOOT DID NOT MOVE OFF THE BRAKE PEDAL DURING ANY OF THE PRECEDING SEQUENCE. ONLY THE NHTSA AND POSSIBLY THE MANUFACTURER WOULD KNOW IF THIS IS A ONE IN A BILLION-HOURS OR A MORE COMMON OCCURRENCE. I AM WILLING TO ANSWER ANY QUESTIONS THE NHTSA OR THE MANUFACTURER MIGHT HAVE. I GRADUATED FROM MIT, WORKED OVER 29 YEARS FOR THE LEADING USA COMMERCIAL AIRCRAFT MANUFACTURER AND AM CURRENTLY RETIRED.