Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2010 Mazda CX-9 owners, lightly cleaned up (personal details are redacted by NHTSA).
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.
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. …
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.
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.
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.
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 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. …
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. …
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.
Tl* the contact owns a 2010 Mazda CX-9. The contact stated that while driving 25-30 MPH, the vehicle shutoff with the check engine warning light illuminated. The contact checked under the hood and noticed the coolant reservoir was empty. The contact pushed the vehicle to her residence. The contact stated that the next day she noticed coolant mixed in with the engine oil. The contact called jack giambalvo Mazda (2425 industrial hwy, york, pa 17402, [phone]) and was informed that the failure May be the water pump however, the vehicle was not diagnosed nor repaired. The failure mileage was 127,422. The water pump was previously replaced at 61,000.
Engine complaints in other CX-9 years
Frequently asked questions
How common are engine problems on the 2010 Mazda CX-9?
NHTSA has 21 complaints about the engine & cooling of the 2010 Mazda CX-9, 13% of the model year's 162 complaints. The component named most often is engine (1 mentions).
Is there a recall for 2010 Mazda CX-9 engine problems?
No. NHTSA lists no engine & cooling recall for the 2010 Mazda CX-9, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2010 Mazda CX-9 engine problems start?
Half of the complaints with a recorded mileage happened before about 75,000 miles, and 20% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.