Experiencing an engine coolant over temperature warning in your 2016 Ford Explorer can be concerning. As a seasoned auto technician at obd-de.com, I understand the frustration and potential engine damage this issue can cause. Often, this problem is linked to a malfunctioning coolant temperature sensor, also known as the Cylinder Head Temperature (CHT) sensor. This guide will walk you through the process of diagnosing and replacing the coolant temperature sensor on your 2016 Ford Explorer, specifically focusing on models with the 3.5L V6 engine, which often presents this issue.
Before diving in, it’s crucial to understand that while replacing this sensor can be a DIY job, it’s not for the faint of heart. The sensor’s location under the intake manifold significantly complicates the process, turning what should be a simple sensor swap into a more involved undertaking. We’ll break down the steps clearly, but if you’re uncomfortable with complex automotive repairs, seeking professional help is always a wise decision.
Understanding Engine Coolant Over Temperature in Your 2016 Ford Explorer
An engine coolant over temperature condition indicates that your engine is running hotter than it should. Ignoring this warning can lead to serious engine damage, including warping cylinder heads, cracked blocks, and ultimately, engine failure. The coolant temperature sensor plays a vital role in monitoring your engine’s temperature and relaying this information to the engine control unit (ECU). The ECU then uses this data to adjust cooling fan operation, fuel mixture, and ignition timing to maintain optimal engine temperature.
When the coolant temperature sensor fails, it can send incorrect readings to the ECU. This might result in:
- Inaccurate Temperature Gauge Readings: The temperature gauge on your dashboard may fluctuate erratically or read high even when the engine isn’t actually overheating.
- Engine Overheating Warning Light: The most obvious sign is the “engine coolant over temperature” warning light illuminating on your dashboard.
- Poor Engine Performance: The ECU might mismanage fuel and timing, leading to reduced power, rough idling, and decreased fuel economy.
- Engine Damage: If the sensor fails to detect true overheating, or falsely indicates overheating when it’s not occurring, it can prevent the cooling system from functioning correctly, potentially leading to real engine damage.
Is it the Coolant Temperature Sensor? Troubleshooting Steps
While a faulty coolant temperature sensor is a common cause for the “engine coolant over temperature” warning in 2016 Ford Explorers, especially those with the 3.5L V6 engine, it’s essential to rule out other potential issues before proceeding with sensor replacement.
Here are some initial checks:
- Check Coolant Level: Ensure your coolant reservoir is filled to the appropriate level. Low coolant is a primary cause of overheating.
- Inspect for Coolant Leaks: Look for any visible leaks around hoses, the radiator, water pump, and under the vehicle.
- Examine the Radiator Fan: With the engine running and warmed up, check if the radiator fan is operating. If it’s not turning on, this could be the issue, or the sensor preventing it from activating.
- Thermostat Function: A stuck thermostat can prevent coolant from circulating properly, leading to overheating. However, diagnosing a thermostat often requires further investigation.
If these basic checks appear normal, and especially if you’re experiencing erratic temperature gauge readings or suspect a sensor malfunction, replacing the coolant temperature sensor becomes a likely solution.
Replacing the Coolant Temperature Sensor: A Step-by-Step Guide
Disclaimer: This guide is for informational purposes and intended for experienced DIY mechanics. If you are not comfortable with these procedures, please seek professional automotive service. Working on your vehicle involves risks, always prioritize safety.
As mentioned, accessing the coolant temperature sensor on the 2016 Ford Explorer 3.5L V6 engine requires removing both the upper and lower intake manifolds. This significantly increases the complexity of the job. Let’s proceed step-by-step.
Tools and Materials Needed:
- New Coolant Temperature Sensor for 2016 Ford Explorer 3.5L V6
- New Upper and Lower Intake Manifold Gaskets
- Socket Set and Ratchet
- Torque Wrench
- Screwdrivers
- Pliers
- Coolant Drain Pan
- New Engine Coolant
- Shop Rags
- Safety Glasses
- Gloves
Step 1: Upper Intake Manifold Removal
This section details the removal of the upper intake manifold. Refer to the images provided for visual guidance throughout this process.
-
Disconnect the Air Cleaner Outlet Pipe: Begin by removing the Air Cleaner (ACL) outlet pipe. This provides access to components beneath.
Alt text: Disconnecting the air cleaner outlet pipe on a 2016 Ford Explorer engine to access the intake manifold.
-
Disconnect Electrical Connectors and EVAP System: Disconnect the electrical connectors for the EVAP (Evaporative Emission) canister purge valve and the throttle body. Detach the wiring harness pin-type retainer to free the wiring. Next, disconnect the EVAP vapor tube from the EVAP canister purge valve and detach it from its retainers.
Alt text: Unplugging the EVAP canister purge valve and throttle body electrical connectors during upper intake manifold removal on a Ford Explorer.
-
Disconnect Vacuum and Ventilation Hoses: Release the clamps and disconnect the power brake booster vacuum supply hose and the crankcase ventilation hose from the upper intake manifold.
Alt text: Detaching the power brake booster vacuum hose and crankcase ventilation hose from the upper intake manifold of a 2016 Ford Explorer.
-
Detach Coolant Tube Retainers: Detach the two coolant tube retainers from the upper intake manifold.
Alt text: Removing coolant tube retainers from the upper intake manifold in preparation for removal on a Ford Explorer.
-
Remove Upper Intake Manifold Support Bracket Bolt: Locate and remove the upper intake manifold support bracket bolt.
Alt text: Unscrewing the upper intake manifold support bracket bolt on a 2016 Ford Explorer engine.
-
Remove Upper Intake Manifold Bolts and Manifold: Remove the seven bolts securing the upper intake manifold. Carefully remove the manifold and discard the old gasket.
Alt text: Removing the seven bolts that hold the upper intake manifold in place on a Ford Explorer engine.
Alt text: Lifting off the upper intake manifold after bolt removal to access lower components on a 2016 Ford Explorer.
-
Clean Sealing Surfaces: Thoroughly clean and inspect all sealing surfaces of both the upper and lower intake manifolds. This is crucial for a proper seal with the new gaskets.
Alt text: Cleaning the sealing surfaces of the upper and lower intake manifolds to ensure a leak-free seal after reassembly.
Step 2: Lower Intake Manifold Removal
Now we proceed to remove the lower intake manifold to access the coolant temperature sensor.
-
Prepare Vehicle and Drain Coolant: Position your Ford Explorer on a level surface or hoist (if available). Release fuel system pressure (refer to your vehicle’s service manual for the correct procedure). Disconnect the battery ground cable for safety. Drain the engine coolant into a drain pan.
Alt text: Draining the engine coolant from a Ford Explorer as part of the lower intake manifold removal process.
-
Remove Upper Intake Manifold (Already Done): Ensure the upper intake manifold is already removed from the previous step.
-
Disconnect Fuel Injector Connectors: Disconnect the electrical connectors from all six fuel injectors.
Alt text: Unplugging the electrical connectors from the fuel injectors on a 2016 Ford Explorer engine.
-
Disconnect Fuel Supply Tube: Disconnect the fuel supply tube-to-fuel rail quick connect coupling. Carefully detach the fuel supply tube and move it aside. Remove the bolt from the fuel supply tube-to-rail bracket.
Alt text: Disconnecting the fuel supply tube from the fuel rail during lower intake manifold removal on a Ford Explorer.
-
Remove Thermostat Housing Bolts: Remove the two bolts that secure the thermostat housing to the lower intake manifold.
Alt text: Removing the bolts holding the thermostat housing to the lower intake manifold of a 2016 Ford Explorer.
-
Remove Lower Intake Manifold Bolts and Manifold: Remove the ten bolts securing the lower intake manifold. Remove the lower intake manifold and discard both the intake manifold and thermostat housing gaskets.
Alt text: Unscrewing the ten bolts that fasten the lower intake manifold to the engine block.
Alt text: Lifting off the lower intake manifold to expose the coolant temperature sensor location on a Ford Explorer engine.
-
Clean Sealing Surfaces: Clean and inspect all sealing surfaces on the engine block and lower intake manifold. Cleanliness is paramount to prevent leaks.
Alt text: Cleaning the sealing surfaces on the engine block after removing the lower intake manifold to ensure a proper gasket seal.
Step 3: Coolant Temperature Sensor Replacement
With the intake manifolds removed, the coolant temperature sensor is now accessible.
-
Disconnect Sensor Connector: Disconnect the electrical connector from the coolant temperature (CHT) sensor.
Alt text: Unplugging the electrical connector from the coolant temperature sensor (CHT) on a Ford Explorer engine.
-
Remove and Replace Sensor: Remove the old coolant temperature sensor. Important: Do not reuse the old sensor. Install a new sensor and tighten it to the specified torque of 10 Nm (89 lb-in) using a torque wrench.
Alt text: Removing the old coolant temperature sensor and preparing to install a new sensor on a 2016 Ford Explorer engine.
Alt text: Installing the new coolant temperature sensor and connecting the electrical connector on a Ford Explorer engine.
-
Reconnect Sensor Connector: Reconnect the electrical connector to the new coolant temperature sensor.
Step 4: Reassembly and Final Steps
Reassemble the components in reverse order of disassembly, using new gaskets for both the lower and upper intake manifolds.
- Install Lower Intake Manifold: Install the lower intake manifold with a new gasket and torque the bolts to 10 Nm (89 lb-in) in the specified sequence (refer to the torque sequence diagram in a service manual).
- Install Thermostat Housing Bolts: Reinstall the thermostat housing bolts and tighten to 10 Nm (89 lb-in).
- Reconnect Fuel Supply Tube: Reconnect the fuel supply tube to the fuel rail and secure the bracket bolt to 10 Nm (89 lb-in).
- Reconnect Fuel Injector Connectors: Reconnect the electrical connectors to the fuel injectors.
- Install Upper Intake Manifold: Install the upper intake manifold with a new gasket. Tighten the bolts in the specified sequence in two stages: Stage 1 to 10 Nm (89 lb-in), Stage 2 an additional 45 degrees.
- Install Upper Intake Manifold Support Bolt: Reinstall the upper intake manifold support bolt and tighten to 10 Nm (89 lb-in).
- Reattach Coolant Tube Retainers: Reattach the coolant tube retainers to the upper intake manifold.
- Reconnect Vacuum and Ventilation Hoses: Reconnect the power brake booster vacuum hose and crankcase ventilation hose.
- Reconnect EVAP System and Throttle Body: Reconnect the EVAP vapor tube and electrical connectors for the EVAP canister purge valve and throttle body.
- Install Air Cleaner Outlet Pipe: Reinstall the air cleaner outlet pipe.
- Reconnect Battery: Reconnect the battery ground cable.
- Refill Coolant: Refill the cooling system with the correct type and amount of engine coolant.
- Bleed Cooling System: Properly bleed the cooling system to remove any air pockets. Refer to your vehicle’s service manual for the correct bleeding procedure.
Post-Replacement Checks and Tips
- Monitor Temperature Gauge: After completing the repair, start your Ford Explorer and monitor the temperature gauge closely. Ensure it reaches normal operating temperature and stays stable.
- Check for Leaks: Inspect for any coolant leaks around the intake manifold and hose connections.
- Test Drive: Take your vehicle for a test drive to ensure the “engine coolant over temperature” warning does not reappear and that the engine is running smoothly.
Conclusion
Replacing the coolant temperature sensor on a 2016 Ford Explorer with a 3.5L V6 engine is a complex task due to its location. While DIY replacement is possible with careful attention to detail and the right tools, it requires significant mechanical knowledge and experience. If you are unsure at any point, it is always best to consult a certified mechanic. By following these steps and prioritizing safety, you can address the “2016 Ford Explorer Engine Coolant Over Temperature” issue and get your vehicle back on the road.
