Component Location Overview
In this video, I provide a clear and direct look at the location of the thermostat for the 2015–2018 Lincoln MKC with the 2.0L EcoBoost engine. On this platform, the thermostat is located within a housing assembly usually found on the driver’s side of the engine block, where the lower radiator hose connects. Because the EcoBoost engine uses a fairly complex cooling circuit, this visual guide is essential to help you distinguish the thermostat housing from other coolant-related components like the water pump or heater core connections, saving you from unnecessary disassembly.
Benefits for DIY Repairs
A stuck thermostat is a common cause of either an engine that never reaches operating temperature (stuck open) or an engine that overheats quickly (stuck closed). Because this job involves working with the cooling system, repair shops often include a “system flush” and significant labor in their quotes. By doing this yourself, you can resolve the temperature regulation issue efficiently and ensure your engine runs at the optimal temperature for fuel efficiency and longevity.
Common Symptoms of Failure
If your MKC’s thermostat is failing, you may notice:
- Engine Overheating: If the thermostat is stuck closed, coolant cannot flow to the radiator, causing the temperature gauge to spike toward the red zone quickly.
- Engine Takes Too Long to Warm Up: If it is stuck open, the engine will run cooler than designed, which can lead to poor fuel economy and reduced heater output in the cabin during winter.
- Fluctuating Temperature Gauge: You might see the needle jump between “cold” and “normal” as the thermostat intermittently binds or opens.
- Check Engine Light: A P0128 code (“Coolant Temperature Below Thermostat Regulating Temperature”) is the most common indicator that the computer has detected the engine isn’t reaching its target operating temperature in the expected time.
Safety Precautions
Working with the cooling system on a pressurized engine requires specific safety steps:
- Engine MUST Be Cold: Never open the cooling system while the engine is hot. The system is pressurized, and scalding coolant can spray out, causing severe burns. Wait several hours after the engine has been running.
- Manage Fluid Loss: When you open the thermostat housing, a significant amount of coolant will spill out. Use a large drain pan to catch the fluid and keep it away from pets (antifreeze is toxic). Have plenty of shop rags ready to keep the engine block clean.
- Air Pockets (The “Burp”): After replacing the thermostat and refilling the system, you must “burp” the cooling system to remove trapped air. Air pockets can cause hot spots and further overheating. Run the engine with the heater on and monitor the level carefully as the air bubbles out.
- Gasket Integrity: Ensure you clean the mating surface of the housing perfectly before installing the new thermostat and gasket. Any leftover old gasket material will cause a persistent coolant leak.
Expert Support
I am a mechanic with extensive professional experience in automotive diagnostics and repair. The cooling systems on these 2.0L EcoBoost engines can be finicky when it comes to air bubbles. If you are having trouble getting the system to bleed correctly or if you are unsure if your issue is the thermostat or a failing water pump, leave a comment below. I am here to help you get your MKC’s cooling system back in order.