CarComplaints.com Notes: The only area of real concern for 2010 Mazda CX-9 owners is the brake booster.

In 2014, Mazda extended the warranty on the 2007-2013 CX-9 brake booster to 7 years / 90,000 miles. However this extended warranty has expired, so buyer beware.

This Mazda CX-9 brake booster failure isn't terrible in terms of repair cost — it "only" costs $550 average to fix. However it is a safety issue when the brake booster fails as it increases stopping distance. Owners have reported having to stomp on the brake pedal, & crashes/injuries have been reported due to this CX-9 brake booster defect.

2.7

hardly worth mentioning
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
52,880 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2010 Mazda CX-9 engine problems

engine problem

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2010 Mazda CX-9 Owner Comments

problem #17

May 262023

CX-9

  • miles

A D V E R T I S E M E N T S

Water pump failure causing catastrophic engine damage

- Dacula, GA, USA

problem #16

Mar 162022

CX-9

  • 160,000 miles
The contact owns a 2010 Mazda CX-9. The contact stated while conducting a routine check, he noticed that the coolant and the oil levels were low. An independent mechanic diagnosed that the coolant was leaking into the engine. The vehicle was not repaired. An unknown dealer was contacted and informed the contact that the VIN was not included in a recall related to the failure. The manufacturer was not notified of the failure. The failure mileage was 160,000.

- Sherrodsville, OH, USA

problem #15

Apr 162022

CX-9

  • miles
The water pump failed and leaked coolant into the engine, causing motor damage which requires motor replacement. There was no evidence of any failure until the vehicle overheated while being driven. This is a known design flaw of the engine design but no recall has been issued.

- Tacoma, WA, USA

problem #14

Mar 152022

CX-9

  • miles

A D V E R T I S E M E N T S

I had engine failure with a complete loss of power and a shuttering of the steering wheel while pulling into a parking lot and going less than 30 miles per hour. The temperature gauze went from cold to hot suddenly. There were no leaks of coolant or oil and no signs that the engine was out of water or that the water pump had "melted". On the final car repair trip we found out that the engine has an internal water pump that failed and resulted in oil & water getting into the engine. The engine light NEVER came on, I had complained about the tire pressure light blinking on and off in November 2021 and the deceleration issue I was having. The dealer did a coolant flush 11/2021. In early March 2022 the engine shut off as I was backing out of the driveway. I took it to a repair shop nearby they could not find anything wrong except that the car went into limp mode. They also did a coolant flush and radiator cap exchange since I forgot I had just done one on Nov. Less that a week later the engine failed again. We towed the car to the dealer for the third trip in less than four months. I am really disappointed that Mazda failed to recall the engine. I could have been seriously hurt if I had been traveling at high speeds. The CX9 had less than 135,000 miles at 12 years old.

- Austin, TX, USA

problem #13

Jun 192021

CX-9

  • miles
Our 2010 Mazda CX-9 stopped on the highway and had to be towed away. The dealer determined it was an engine failure due to a faulty water pump. It had leaked into the engine, causing permanent damage. No warning lights. The car just stopped. Two dealerships did not want to repair. There is a class action lawsuit. https://www.ktmc.com/mazda-water-pump-engine-failure There should be a recall. We need a refund for the repair we had done, totaling more than $7000. Please look into this safety issue. Mazda Corporate has our complaint on file. We are expecting a refund.

- Belmont, MA, USA

problem #12

Jul 142021

CX-9

  • miles
My vehicle completely shut off while idling in park with no prior warning to anything being wrong. Put coolant in since the container was empty. Replaced thermostat, but vehicle was still overheating. Had it towed to Flow Mazda of Fayetteville and had them run a diagnostic. They determined that coolant was leaking into the oil due to a broken water pump. It was estimated to cost approximately $5,000 to repair with no guarantee that it would fix the problem. They pulled 4 sludge codes. There is currently a lawsuit against Mazda for this specific problem that was filed in 2019.

- Fayetteville, NC, USA

problem #11

Sep 182020

CX-9

  • 108,000 miles

A D V E R T I S E M E N T S

We were sitting in a parking lot waiting on a pizza. We noticed the A/C wasn't cooling, and then noticed the car was starting to overheat. (this was the first time ever). We checked the radiator, it was empty. We purchased coolant and filled up the reservoir. Never saw any leaks. Car started but seemed sluggish like the battery was low. We got our pizza and drove about 6 miles where we parked till we took it to the dealer on Monday. Our mechanic called me later to tell me that the water pump had failed and that it had leaked into the oil pan and we would have to have the engine replaced. The repair total for my CX9 is at $9K. We have 108,000 miles on the vehicle. My vehicle is still sitting at the dealer.

- Spring, TX, USA

problem #10

Sep 132019

CX-9

  • 66,234 miles
While driving on a city street, and without any indication that something was wrong, all of a sudden three warning lights came on, engine lost power, accelerator, brakes and steering were unresponsive. I am lucky I could manage to get into a turn lane and stop using the emergency brake. Car was towed to Mazda. Told water pump failed and now coolant is mixed with engine oil, engine likely ruined. The car has 66,000 miles on it. Internet research shows this is a known problem on Cx-9S and Mazda did not issue recall. Is it safe for these cars to be on the roads? see https://www.carcomplaints.com/news/2019/Mazda-water-pump-lawsuit.shtml

- Centennial, CO, USA

problem #9

Sep 112019

CX-9

  • 134,000 miles
Me and my husband were on our way home from work. The car suddenly overheated and we lost power on I-35, we were able to get the car to an exit and was nearly hit by another car due to loss of steering and power. We had the car towed to a Mazda dealership. There is engine coolant in the oil and we are told it needs a new motor.

- Eudora, KS, USA

problem #8

May 152019

CX-9

  • 80,000 miles
The engine overheated while driving on a highway at high speed and failed without warning. After investigation it was found that water pump malfunctioned forcing coolant into the engine. It is now completely inoperable and the car has only around 80,000 miles on it. This is a major safety issue! the car was serviced and oil changed just a few months before this happened. This is a major design flaw on Mazda's part, which they seem to know about and never issued a recall to get all the cars fixed. Replacing an engine is not something most families have the budget for or even think about when the car is less than 10 years old. There were no warning signs of water pump failure. Mazda needs to warn Cx-9 owners with tsb or recall the water pump. The water pump is not buried inside the engine and cannot be visually inspected. Having a vehicle shut off abruptly when traveling at high speeds is a serious risk for both driver, vehicle occupants and surrounding motorists. I hope NHTSA takes this complaint seriously and takes action before a serious or fatal injury occurs.

- Boulder, CO, USA

problem #7

Mar 262019

CX-9

  • 90,000 miles

A D V E R T I S E M E N T S

Vehicle was in motion on a busy street when suddenly the check engine light came on the ac stopped coming out cold, and the car stopped accelerating would only go up to 20 mph, the car started making rattling noises and I drove by to the nearest place to stop and water fell out of the front bottom right of the car.. the water pump messed

- La Porte, TX, USA

problem #6

Jul 152018

CX-9

  • 10 miles
While traveling 65mph on highway with family the vehicle shut down, engine light appeared and we nearly were struck by another vehicle when pulling over. Cx-9 was towed 75 miles to mechanic who informed us coolant entered the engine from failed water pump and engine needs replacement ($4000). Mazda service manager confirmed this is not uncommon and confirmed engine will need to be replaced. When researching Cx-9 water pump failure online I found many disturbing testimonials of other Cx-9 owners with similar experiences. There were no warning signs of water pump failure. Mazda needs to warn Cx-9 owners with tsb or recall the water pump. The water pump is not buried inside the engine and cannot be visually inspected. Having a vehicle shut off abruptly when traveling at high speeds is a serious risk for both driver, vehicle occupants and surrounding motorists. I hope nstsa takes this complaint seriously and takes action before a serious or fatal injury occurs.

- Lower Merion, PA, USA

problem #5

Oct 032016

CX-9

  • 75,000 miles
After recently receiving our vehicle back from a Mazda dealer for warranty repairs on the ptu and control arms, we were driving down the highway at 65 mph - initially going up a hill in the mountains. The car would not shift gears (an automatic) and then would not accelerate past 30 mph. No dummy lights lit whatsoever. We got to the top of the hill and having no place to pull off on the highway mountain shoulder, stayed in the lane of traffic with our hazards on. The down side of the hill was a 6% grade with a cliff on the other side of the guard rails. All of a sudden - the power steering went out and the car was hard to steer. There was still no place to pull over on the mountain highway, so we coasted. We then noticed the RPM's were at 0 and all the dummy lights that are on when the car ignition is in accessory were lit up. The car had turned off - while we were going 65 mph on a 6% grade. No warning - no sounds, smoke, dummy lights - just off. Very amazingly dangerous. We were very lucky to not die a fiery death. My husband was able to keep calm and thankfully the brakes worked - we were able to stop towards the bottom of the hill. We had the car towed as it wouldn't start/stay running. The diagnosis by the dealer (not the dealer who did the prior warranty work) was a failed engine rod. Would have been nice to get a check engine light before having the car completely shut off. We drove the vehicle for less than 100 miles after receiving back from the warranty work and now this.

- Boulder, CO, USA

problem #4

May 022014

CX-9

  • 80,801 miles
When I am at a stop ad start my vehicle accelerates without my assistance, this happened also while backing up and my foot was on the brake.

- Orande City , FL, USA

problem #3

Jan 022014

CX-9 6-cyl

  • 41,000 miles
The car has been turning off while driving with no prior indications or warnings. Engine turns off and steering wheel freezes and locks up. This has occurred multiple time and we have taken the car to the dealer a number of times who has inspected it and even kept it at the shop drove it for a number of days and could not pinpoint the problem. We have made Mazda usa aware of the issue and the potential threat of this vehicle (they gave us a case # 149456450) however, sadly their attitude is that if the problem cant be pinned then it does not exist. This is a clear ignorance on Mazda usa's part and putting the public in a risk with this vehicle.

- Great Neck , NY, USA

problem #2

Jan 062014

CX-9 6-cyl

  • 25,500 miles
Several weeks ago the brakes started making a hissing noise when I would depress the brake. Then, the car would brake as usual until I needed to come to a complete stop, whereas then I would need to depress the brake very hard to make the car stop, which then it would stop very suddenly. The most recent event occurred when my husband was driving down the road about 45 mph and had hit the brakes and the engine completely shut off, all the warning lights came on and it was very difficult for my husband to pull the car over and come to a stop. The engine did start back up and we drove all the way home and have not since driven the vehicle.

- Pembroke Pines, FL, USA

problem #1

Oct 132012

CX-9 6-cyl

  • 38,409 miles
Ticking noise was heard as I accelerated the vehicle and as left turns where made. The ticking noise was louder when the engine was cold. Mazda recommended to replace engine immediately without further inspection. When I asked what was wrong with the vehicle Mazda said sludge was found on the dipstick. They blamed me the consumer and Mazda would not honor my extended warranty which I purchased though them at the time of my initial purchased of the vehicle.

- Katy, TX, USA

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