Ford Fusion Engine Coolant Thermostat: A Guide for 2013-2020 Models
Keep your Fusion's engine from overheating or running too cold by understanding and choosing the right thermostat.
- The most common failure is a stuck-open thermostat, which causes a P0128 check engine light code.
- Replacement difficulty varies drastically by engine; the 2.5L is DIY-friendly, while the 1.5L EcoBoost is very difficult and best left to a pro.
- It is highly recommended to replace the entire thermostat and housing assembly, not just the internal valve.
- Be aware of separate, serious coolant intrusion issues on 1.5L and 2.0L EcoBoost engines, as overheating can worsen engine problems.
Is Your Fusion's Thermostat Failing?
A bad thermostat can fail in two ways: stuck open or stuck closed. A thermostat that is stuck open is the most common issue for the Ford Fusion and will usually trigger a check engine light. A thermostat stuck closed is much more dangerous and can quickly lead to severe engine damage from overheating.
Common Symptoms of Failure:
- Engine runs too cold: If the thermostat is stuck open, the engine will take a very long time to warm up. You may notice the temperature gauge stays on 'C' or lower than normal. This will often cause a P0128 check engine code.
- Poor heater performance: Since the engine isn't getting hot enough, the air blowing from your vents may only be lukewarm, especially in winter.
- Engine overheating: If the thermostat is stuck closed, coolant can't get to the radiator to cool down. The temperature gauge will spike into the red, and you may see a "High Engine Temperature" warning. This is a critical situation; pull over and shut off the engine immediately.
- Coolant leaks: The plastic thermostat housing can crack over time, causing coolant to leak. On the 2.5L engine, this is a common failure point.
Important Note on EcoBoost Engine Issues
While not directly a thermostat issue, many 1.5L and 2.0L EcoBoost engines in 2013-2020 Fusions are subject to Technical Service Bulletins (TSBs) and customer satisfaction programs for a serious problem involving coolant leaking into the engine cylinders (coolant intrusion). Symptoms include low coolant, white exhaust smoke, and a rough running engine. A thermostat stuck closed can cause overheating, which puts extra stress on the engine and could potentially worsen these known issues. If you have an EcoBoost engine, be aware of these separate but critical cooling system problems.
Choosing the Right Aftermarket Thermostat
When replacing your thermostat, you have several options. For most owners, replacing the entire thermostat housing assembly is recommended over just the thermostat itself, as it simplifies installation and replaces the leak-prone plastic housing.
- OEM (Motorcraft): Motorcraft is Ford's official parts brand. Choosing Motorcraft ensures you get the exact same part your car came with from the factory. It's a reliable, though often more expensive, choice.
- Premium Aftermarket (e.g., Gates): Brands like Gates are well-respected and produce parts that meet or exceed OEM quality. They are a dependable alternative to OEM and are often preferred by professional mechanics. Some owners of 2.5L Fusions opt for aftermarket aluminum housings as an upgrade over the original plastic part.
- Standard Aftermarket (e.g., Motorad, Calorstat, Facet): These brands offer a good balance of value and quality. They are a cost-effective solution for daily driving and are widely available.
Pro Tip: Always verify the part fits your Fusion's specific engine (1.5L, 2.0L, 2.5L, etc.) before purchasing. The thermostat location and design vary significantly between engines.
Cost to Replace a Ford Fusion Thermostat
The cost depends heavily on your engine type due to major differences in labor time.
| Part/Service | Estimated Cost |
|---|---|
| New OEM (Motorcraft) Part | $40 - $150 |
| New Aftermarket Part | $20 - $120 |
| Shop Labor | $150 - $500+ |
| Total Estimated Cost | $170 - $650+ |
Labor for the 2.5L engine will be on the low end of this range, while the 1.5L EcoBoost will be on the high end due to its difficult placement.
Frequently Asked Questions
Is the thermostat the same for all Fusion engines?
No. The thermostat part, housing design, and location are different for the 1.5L EcoBoost, 2.0L EcoBoost, and 2.5L Duratec engines. You must buy the correct part for your specific engine.
Can I replace the thermostat myself?
It depends on your engine and skill level. On the 2.5L engine, the job is relatively straightforward for a DIYer. 🎬 See this 2.5L coolant and thermostat replacement walkthrough However, on the 1.5L EcoBoost, the thermostat is extremely difficult to access, requiring removal of the alternator and other components; this is best left to a professional. The 2.0L falls somewhere in between.
🎬 Watch: 2.0L EcoBoost thermostat location and replacement guideMy car has a P0128 code. Is it the thermostat?
Almost certainly, yes. The P0128 code means the engine's coolant failed to reach the proper operating temperature in a set amount of time. This is the classic symptom of a thermostat that is stuck open.
🎬 Watch: How to fix the P0128 engine error codeShould I replace just the thermostat or the whole housing?
For most 2013-2020 Fusions, the thermostat comes as part of a complete housing assembly. It is highly recommended to replace the entire unit. This ensures a proper seal and replaces the plastic housing which can become brittle and leak over time.
Helpful Videos
Technical Specifications
OEM Part Numbers: DS7Z-8575-A DS7Z-8575-B FR3Z-8575-A 3M4Z-8575-B RT-1223 RT-1226
Thermostat opening temperatures typically range from 180°F to 195°F depending on the specific engine and OEM calibration. Most replacements are sold as a complete housing assembly with the thermostat pre-installed.
We Have This Part in Stock
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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