Water Pump Failure

One of the major complaints reported against the ownership of a Mazda CX-9 has to do with water pump failure, most of which happens to first generation models from 2007 through 2013. A water pump may leak due to long use and hence coolant mixes with the engine oil.
Symptoms of a failing water pump include a noticeable drop in coolant levels, visible coolant leaks, and an overheating engine. In some cases, drivers report a strange smell or a milky appearance in the oil.

Brake Booster Problems

Several incidences have been reported regarding brake booster failure for a Mazda CX-9 manufactured between 2007 and 2013. A failed brake booster usually presents serious symptoms, which include a hard-feeling brake pedal or difficult vehicle stops, with sometimes engine stalling. This is usually accompanied by a hissing noise at the moment of pressing the brakes, as this will make the pedal either feel very hard or simply sink to the floor with almost no resistance.

Transmission Issues

While less common, some transmission problems have been reported with the Mazda CX-9, particularly in the 2011 and 2012 model years, where complaints about the transfer case have increased. The transfer case is a very important part of the drivetrain that helps to apportion power to all four wheels in AWD models. If this part fails, harsh shifting, shuddering, and even complete failure of the drivetrain can occur. Bad symptoms of the transfer case include clunking noises while shifting gears, inability to shift gears smoothly, and noticeable vibrations.

Infotainment Screen Delamination

Some owners of the second-generation Mazda CX-9, especially those using models from the 2016 and 2017 model years, complain of issues with an unresponsive infotainment screen.

Over time, the screen usually develops what is commonly referred to as “spider-webbing,” or delamination, in which the surface starts to crack and peel. This condition is especially noticeable in those vehicles that are exposed regularly to direct sunlight or extreme heat. As time goes on, the adhesive that keeps the screen in place breaks down, which causes the display to deteriorate. Although Mazda has extended the warranty on these screens for affected models, owners of vehicles outside of this warranty window may have to pay for replacements, which can cost several hundred dollars.

Electrical and Internal Accessory Problems

Other factors that can lead to trouble for owners of Mazda CX-9 models might be electrical issues, specifically with internal accessories such as infotainment, GPS, alternators, and car batteries.

There are quite a lot of driver complaints about the dead battery, malfunctioned GPS systems, and problematic alternator around 15 000 mileage. All those are solved by replacement; the more serious issues will require, however professional interference. There, the replacement of the alternator may also be necessary, what can come expensive.