9 Most Common Mazda CX-9 Problems (Explained)

The Mazda CX-9 is a midsize three-row SUV that was first released in 2007.

The second generation CX-9, which debuted in 2016, was significantly redesigned, boasting a luxurious interior that rivals offerings from more expensive brands.

In this article, we’ll take a look at some of the most common issues, problems, and complaints Mazda CX-9 owners have had over the years.

1. Cylinder Head Cracking 

There have been quite a few reports of second generation Mazda CX-9s developing coolant leaks caused by a cracked cylinder head. In some cases, it’s the engine block that cracks.

This problem is more common in the early model years, but it can also affect cars made up to 2020.

Common signs that your cylinder head is cracked include:

• Coolant leaks
• Green coolant residue on exhaust manifold or oil filter
• Coolant smell
• White smoke from exhaust
• Overheating or high engine temps 
• Heater stops blowing hot air
• Low coolant levels in the reservoir
• Check engine light
• Rough idle
• Coolant mixing with engine oil

Here is how a few owners described their experience on the Mazdas247.com forum:

“I️ just discovered that I️ have a cracked cylinder head and need to replace the engine on my 2017 CX-9, with 98k miles. The replacement cost is $8k ”

“My 2018 touring plus is officially in the cracked/warped cylinder head club. Car is at 67000 mi. right now but I think the leak was actually happening around 10,000 miles ago. I had an independent mechanic inspect it and couldn’t find a source of what seemed like a very slow leak. We topped off coolant and I’ve driven it for about 7 months before seeing the coolant level slowly drop until this past week where it was a bit faster.”

“Sadly my 2018 CX-9 (55000 miles) was diagnosed today with a cracked cylinder head. The fix is a new cylinder head, paid by the Powertrain warranty. Coolant level was full. But engine oil light brown.”

The coolant leak and cracked cylinder head issues seem to become more evident once the car reaches 50,000 to 100,000 miles. However, despite the number of cases reported, not all cars will suffer from this issue.

Mazda has already released several TSBs (Technical Service Bulletin) to address this problem. According to the latest ones, CX-9s made on or before June 2020 can suffer from the cylinder head leaks. The only way to fix this is to replace the cylinder head with an updated part.

Unfortunately, if your car is already out of warranty, the repair for a cracked cylinder head can cost upwards of $5,000. However, some owners were able to convince their dealers and Mazda corporate to cover the repair costs out of warranty as a sign of goodwill.

The best way to confirm whether or not you have a crack in the cylinder head is to perform a leak down test. Most garages will be able to do this for you for around $100 to $200.

2. Oil Consumption

The 2021 Mazda CX-9 can suffer from oil consumption issues fairly early on in its life.

Mazda made some changes to its 2.5-liter turbocharged engine for the 2021 model year. Unfortunately, this resulted in many reports of oil consumption or oil burning problems in several models.

Common signs of oil consumption include: 

• Low oil warning
• Low oil level on dipstick
• Blue smoke from exhaust
• Check engine light

The oil consumption issue typically starts manifesting itself at relatively low miles. In a lot of cases, the oil light will come on just before the next scheduled oil change and owners typically have to top it up with at least 1 quart.

Here is how one owner on MazdaForum.com described their experience:  

“I purchased a 2021 CX-9 Signature in May with a little over 12K miles. At 15,833 miles, the check oil light came on and it needed a full quart of oil.” 

Other CX-9 owners on Mazdas247.com had this to say: 

“I have a 2021 CX-9 Touring with 6300 miles on it, no oil changes yet. Oil level light just come on tonight.”

“My 2021 cx-9 sig with 20K miles seems to be burning about 1 qt per 7,000 miles. I do mostly freeway driving at 60-70 mph. The dealer tells me it’s within limit of course, but on the last couple of oil changes, my oil pressure indicator will come on about 500-600 miles before my oil change is due.”

According to a TSB released by Mazda, the excessive oil consumption is caused by a faulty valve stem seal that allows oil to get into the combustion chamber where it gets burned up. This issue affects CX-9s made from October 2020 to September 2021.

The only way to fix this is to open up the valvetrain and replace the faulty valve stem seals with an updated part. This repair should be free of charge if the car is still under warranty.

3. Transfer Case Failure

One of the most common problems of the first generation CX-9 is the premature failure of the transfer case.

The transfer case is responsible for distribution power between the front and rear wheels and is only found in the all-wheel drive models. 

The first generation CX-9 used the same transfer case as the Ford Edge which also suffered from similar issues.

Symptoms of a broken transfer case include:

• Burnt oil/transmission fluid smell
• Excessive shaking and vibration
• Grinding or humming noises
• Fluid leaks
• Traction control light on dash
• Loss of all-wheel drive

Here is how a few owners described their experience:

“I have a 2010 CX-9 with 45k miles and saw this thread a few days ago. Just yesterday got the tell-tale noise/smell and took it to my local shop. Turns out I have the failing transfer case.”

“I am getting the same issues with my CX-9. Burning oil smell after the drive. Loud clanking noises that come in and go. This morning the noise was really bad and the car shook and jerked while slowing down. at one point it seems that the wheel was locked. This morning it was so bad that I had to get it towed to the dealer. After a few hours he called and said that the Transfer case (PTO) went bad and needs to be replaced. I am at 45 K + and it is a 2012 CX-9.”

“09 mazda cx9 88,0000 miles. Started to hear a whine between 30 and 60 mph most noticeable when throttle on or coasting down hill. Also noticed sulfur smell in cabin. Brought to Mazda. Tech said easy diagnosis of transfer case.”

The only way to fix this problem is to replace the entire transfer case which typically costs around $2,000. Unfortunately, a broken transfer case can also damage the transmission, which is usually only evident once the transfer is removed. 

Mazda did extend the warranty of the transfer case to 7 years or 90,000 miles, whichever came first. But at this point in time, this warranty extension would have already expired.

4. Water Pump Failure

Another common problem of the first generation Mazda CX-9 is the eventual failure of the water pump.

The first gen Mazda CX-9’s V6 engine is based on the Ford V6 Cyclone engine which was used in many Ford vehicles from the same era. Both engines used the same water pump and had similar failures.

When the CX-9’s water pump fails, it can cause coolant to mix in with the oil and eventually cause catastrophic engine damage because its components are no longer properly lubricated.

Symptoms of a failing water pump include:

• Low coolant levels
• Visible coolant leaks
• Coolant smell
• Overheating and high engine temps
• Milky oil 
• Heater not blowing hot air

Here’s is how a few owners described their experience:

“2010 CX9, 125k miles, water pump leak. Dealership quoting around $4000 to replace leaking water pump.” 

‘2010 Cx-9 Sport. 160,000 miles. First thing I noticed the other day was there was steam/smoke coming from both exhausts. Then came a funny smell when I turned on the air. Coolant level had dropped a bit since I last checked a few weeks ago. Then I checked the oil cap. I’ve never seen it in person before but there it was. Milkshake on the oil cap.”

Water pump issues tend to appear once the car reaches 80,000 to 120,000 miles. Although this is not considered a premature failure in other vehicles, the repair is more difficult in the CX-9 because the engine has to be dropped to get to the water pump. All in all, the repair can cost you anywhere from $2,000 to $4,000 if you have it done by the dealer.

Mazda did update the CX-9’s water pump to a dual sprocket design some time in 2011. This resulted in less failures and longer lifespans.

Related: 17 Best & Worst Mazda CX-9 Years (With Facts & Stats)

5. Clicking Noise When Braking

Several second generation Mazda CX-9 owners have complained about a loud clicking noise whenever they step on the brakes.

The clicking usually only occurs at low speeds and soon after shifting into reverse. It should eventually go away after a minute or two. 

Here is how one owner described the problem on the Mazda CX-9 subreddit:

“I have a 2021 CX-9 GT with around 20k miles. I’ve noticed a clicking noise when applying the brakes, only while driving at slow speeds, and mainly within the first 5-10 minutes of driving. This is my second CX-9 and I never had this issue in the past.”

The clicking is often caused by the brake pads shifting out of position in the brake caliper. It can happen even if the pads are not worn out yet.

Mazda eventually addressed this problem in a TSB which recommends attaching a protector inside the caliper to keep the brake pads in the right position, and then applying some additional grease.

6. Brake Booster Problems

The first generation Mazda CX-9 has a tendency to suffer from brake booster failure, which is also one of the most reported problems on the CarComplaints.com website.

Early brake booster failures are more common in the 2007 to 2013 model years of the CX-9.

Symptoms of brake booster failure include:

• Hissing sound
• Brake pedal becomes hard
• Pedal goes straight to the floor with no resistance
• Pedal won’t go back to neutral position
• Brakes don’t stop the car effectively
• Engine stalling issues

Here is how a few owners described their experience:

“My 2011 Mazda CX9 brakes are really bad. I have to literally stand on brakes to make my car stop hitting car ahead. The brakes makes annoying hissing sound when brakes are applied.”

“When pressing on brake pedal, the pedal was so stiff that it didn’t move it all. Quite a scary feeling when your brakes don’t work. I pressed again and they worked. A few days later, I pressed on the brake to stop at a red light. While still pressing on the brake pedal at the light, my foot began to go all the way to the floor.” 

In 2014, Mazda extended the warranty of the 2007 to 2013 CX-9’s brake booster to 7 years or 90,000 miles. Mazda also updated the brake booster starting with the 2014 model year to reduce the number of issues and failures.

Related: 7 Most Common Mazda CX-90 Problems (Explained)

7. Delaminating Infotainment Screen

Early model years of the second generation Mazda CX-9 can suffer from screen delamination issues.

Owners usually start noticing tiny white cracks on the screen that look like crystallization. It’s also commonly referred to as spider webbing. 

It happens more often if the car is parked outside in the hot sun which causes the adhesive in the screen to break down.

This problem typically affects the 2016 to 2017 CX-9 the most and Mazda offered a 7-year/unlimited mile warranty extension for these model years.

However, owners of newer model years have also started to report similar problems with their screens.

Here’s is how a few owners described their experience:

“2018 CX-9 infotainment screen developed spider-web cracks. My cx9 with 53k miles developed the spider-web cracks on the bottom corners. Mazda says I need to pay $500 and they will cover the difference for the repair.” 

“Had same issue on my 2018 while under warranty and had it replaced. Now out of warranty, the replacement part is doing the same thing about 2 years later.”

If your car is already out of warranty, you can find replacement digitizers and screens online and replace it yourself. Just make sure you get a high quality unit because some replacement screens do not have the same image quality as the original.

8. Power Window Issues

The window regulator motors of the first generation CX-9 are very prone to failing after a few years.

When they go out, the windows usually make a horrible grinding noise at certain points, and usually only when trying to close the windows.

Here is how one owner described the issue: 

“I just started hearing a loud grinding sound when I roll the drivers side window up. The grinding only occurs when the window has reached full travel (closed), not during the travel up. Doesn’t making the grinding sound when the window goes down.”

The grinding noise is a result of the window motor’s plastic gears breaking apart over time. You should still be able to fully close the window a bit if you pull it up a bit while activating the switch. 

You can get new window motors for less than $100 and replace them yourself after taking off the door panel. Many owners also choose to take apart the old window motor and just replace the broken plastic gears, which only costs a few dollars.

9. Clogged A/C Drain

The first generation Mazda CX-9’s air conditioner drain lines can get easily clogged after a relatively short period of time.

Symptoms of a clogged A/C line include:

• Water sloshing or whistling sounds when taking turns
• Flooded passenger footwell
• Loud fan noise

Here’s how a few owners described the issue:

“I have a 2015 with only 22K miles and my wife came home today and “oh by the way, I think I hear water in the dash board.” She said that you could hear sloshing whenever you went around a turn. When you made a left turn, the blower motor would kick on high.”

“I own a 2008 Mazda CX-9 and have recently had the problem with the evaporator on the A/C unit not draining properly and backing up into the blower housing.” 

“Our CX9 started making a strange sound near the passenger side dash area whenever I made a turn. Then it started leaking under the glove box.”

“I had a 2007 CX9 before I recently traded it in for the 2017 version. This issue happened in that vehicle constantly. I had to clear out the drain with my air compressor at least twice/yr. Never noticed any cause for the blockage… just an extremely poor design.”

If the clogged drain is not addressed, the excess water can also cause all sorts of electrical issues.

To unclog the AC drain line, you have to jack up the car and get under the driver side. There should be a heat shield just above the exhaust pipe that you can pull up slightly. This should reveal a white plastic drain pipe. You can then use a shop vac to suck out all the gunk and water that’s accumulated inside. 

Related: How Long Do Mazda CX-9 Last? (11 Important Facts)

Mazda CX-9 Pros & Cons

Pros

• Upscale interior
• Good acceleration
• Nimble handling
• Third-row seats
• Great reliability 
• Good ground clearance
• Standard all-wheel drive
• Lots of standard tech

Cons

• More expensive than rivals
• Cramped third-row seats
• Less cargo capacity than competition

What Do The Reviews Say?

“The Mazda CX-9 feels like a smaller midsize SUV in many ways, including the way it drives. It’s a bit more athletic than competitors on a winding road, with confident brake response, and it’s easy to maneuver in tighter confines. The all-wheel-drive system is tuned mainly for inclement road conditions, but it can handle your weekend “soft-roading” excursions.”

“Whether you’re commuting or taking a long road trip, the CX-9 delivers a good degree of comfort. Much of the credit goes to the smooth ride, which strikes a balance between sporty and compliant.” 

“Inside, the CX-9 has well-sculpted front seats that offer ample support, but it’s worth noting the third row is quite small and not as comfortable as many competitors’ back rows. The cabin, however, is luxury-level quiet, which is impressive.”

“All CX-9s come loaded with advanced safety and driver aids such as adaptive cruise, blind-spot warning, rear cross-traffic warning, forward collision warning and lane keeping assistance. They’re well tuned to deal with heavy traffic, and false alarms are rare. Adaptive cruise and lane keeping work well to relieve the burden of heavy traffic.”

“The CX-9 falls behind the competition in cargo and utility. The 14.4 cubic feet behind the third row could be adequate for many shoppers, but for comparison, there’s 21 cubic feet in the class-leading Kia Telluride. Max cargo is equally short, with 71.2 cubic feet in the CX-9 and 87 cubes in the Telluride.”

“The CX-9 is definitely among the leaders in terms of its build quality, especially in top Signature trim. Entry-level models are generally more expensive than the competition, but the Mazda justifies the higher cost by including more standard features. It’s priced fairly competitively at the top end, and the interior closely resembles a luxury-class cabin thanks to exquisite materials, uniform gaps and clean, elegant design. The exterior paint is well done too.”

2023 Mazda CX-9 | Edmunds

What’s the Resale Value of a Mazda CX-9?

Here’s a quick look at used car pricing on Edmunds at the time of writing.

Related: Mazda CX-9 Beeping? (10 Common Causes)