Engine Coolant Thermostat Guide for the 2013-2022 Mazda CX-5
Is your CX-5 engine running too hot or taking too long to warm up? Your thermostat might be the problem.
- There are two different thermostat designs: a simple thermostat for 2013-~2017 models and a complex, expensive Coolant Control Valve (CCV) for ~2018-2022 models.
- A stuck-open thermostat is a known issue on 2018-2022 models, often triggering code P0126 and is covered by a 15-year/150,000-mile warranty extension (SSPD8).
- Symptoms of a stuck-open thermostat include a check engine light (P0128/P0126), slow engine warm-up, and poor heat.
- Overheating is a critical symptom of a stuck-closed thermostat and requires you to stop driving immediately to prevent severe engine damage.
Is Your Mazda CX-5 Thermostat Failing?
A thermostat can fail in two ways: stuck open or stuck closed. Each has its own set of symptoms. For the CX-5, especially later models, a 'stuck open' failure is more common and is even covered by a warranty extension.
Symptoms of a Bad Thermostat
If Stuck Open (More Common):
- Check Engine Light: The most common sign is a check engine light with codes P0126 or P0128. These codes mean the engine isn't reaching its proper operating temperature quickly enough.
- Slow to Warm Up: Your engine takes much longer than usual to reach its normal temperature on the gauge.
- Poor Heater Performance: The air blowing from your vents may not get very hot, especially when the car is idling.
- Low Temperature Gauge: The temperature needle may stay low or fluctuate, dropping on the highway and rising in town.
- Decreased Fuel Economy: An engine that runs too cool is less efficient, leading to worse gas mileage. 🎬 Watch: Learn how to identify and test a bad thermostat.
If Stuck Closed (More Serious):
- Engine Overheating: The temperature gauge will quickly climb into the red. This is a serious condition that can cause major engine damage.
- High-Temperature Warning Light: A red thermometer light will appear on your dashboard. Pull over immediately if you see this.
- Steam from Engine Bay: You may see white steam or smell a sweet coolant odor coming from under the hood.
- Strange Noises: Gurgling or knocking sounds can occur as coolant begins to boil.
Known Issue & Warranty Extension for 2018-2022 Models
Mazda has issued a warranty extension program (SSPD8) for a known thermostat issue on certain 2018-2022 CX-5 models with the 2.5L non-turbo engine. The problem is a 'fail-safe' thermostat that can stick open, causing the exact symptoms described above (Check Engine Light with code P0126, slow warm-up, poor heat). The warranty for this specific failure is extended to 15 years or 150,000 miles. If your vehicle exhibits these symptoms, contact a Mazda dealer with your VIN to check for coverage before paying for a repair.
🎬 See this walkthrough for replacing the newer coolant control valve.Choosing the Right Aftermarket Thermostat
For the Mazda CX-5, there are two different thermostat designs depending on the model year. It is critical to order the correct part for your vehicle.
- 2013 - approx. 2017 Models: These use a traditional, simple thermostat that fits into a housing. It's a relatively inexpensive part.
- approx. 2018 - 2022 Models: These use a more complex and expensive assembly called a Coolant Control Valve (CCV), which has the thermostat integrated into it. This is the part covered by the warranty extension.
While OEM is often recommended by mechanics for a critical part like this, several aftermarket brands offer viable alternatives.
| Brand Tier | Brands | Quality & Notes |
|---|---|---|
| Premium Aftermarket | Beck Arnley, Gates | These brands focus on being direct OE-quality replacements. They are known for matching original form, fit, and function and are a solid choice for reliability without the full OEM price. Beck Arnley specializes in import parts, making it a good fit for Mazda. |
| Standard Aftermarket | Calorstat | Calorstat by Vernet is a well-established European brand that produces reliable cooling system components. While less common in North American parts stores, it is a reputable option if available. |
| Economy Aftermarket | Motorad | Motorad is a budget-friendly option. However, owner and mechanic reviews are mixed, with some reporting premature failures. Given the labor involved in replacement, especially on later models, consider this a short-term or budget-only solution. |
Pro Tip: Check Your Part Before You Buy
For 2017 and 2018 models, there can be an overlap in which part was used. It is best to visually inspect your current thermostat housing or use your VIN to confirm whether you need the simple thermostat insert or the complete Coolant Control Valve assembly before ordering.
Frequently Asked Questions (FAQ)
Is it hard to replace the thermostat on a Mazda CX-5?
It depends on the year. For earlier models (approx. 2013-2017), it is an intermediate DIY job that takes 2-3 hours. Access is tight, and you must remove the battery and battery tray. 🎬 Watch: Step-by-step guide for replacing the thermostat on earlier models. For later models (approx. 2018-2022) with the Coolant Control Valve, the job is more complex and expensive. It may require removing the throttle body for clearance, and mistakes can lead to electrical issues. For these later models, professional installation is recommended unless you are an experienced mechanic.
What is the difference between a thermostat and a coolant temperature sensor?
The thermostat is a mechanical valve that opens and closes to control coolant flow. The coolant temperature sensor is an electronic sensor that measures the coolant's temperature and sends that information to the car's computer. While they work together, they are different parts. A bad sensor can sometimes cause similar symptoms to a bad thermostat, but a P0128 or P0126 code most often points to a faulty thermostat.
Why is the replacement cost so much higher on newer CX-5 models?
Newer models (approx. 2018+) use an integrated Coolant Control Valve (CCV) assembly instead of a simple thermostat. The OEM part for the CCV costs over $400, compared to about $35 for the older style thermostat. The labor is also slightly more intensive, leading to a much higher total repair cost.
Do I need to use special coolant for my Mazda CX-5?
Yes. Mazda specifies FL-22 long-life coolant. It is important to use either the genuine Mazda FL-22 coolant or an aftermarket coolant that is specifically listed as an FL-22 equivalent. Using the wrong type of coolant can cause damage to the cooling system.
Helpful Videos
Technical Specifications
OEM Part Numbers: PE01-15-171 PYFD-15-16ZA
Opening Temperature: Approx. 180-195°F (82-90°C). Coolant Type: Mazda FL-22 or equivalent.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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