If you own a Ford Explorer, F-150, or Expedition with the 3.5L EcoBoost engine, finding a coolant leak near the driver’s side subframe can be alarming. The culprit is often a failed component called the coolant outlet tube.
This part is vital to the engine's performance, and a leak puts you at serious risk of overheating. Here is a comprehensive DIY guide to identify the problem, understand why it failed, and replace the outlet tube the right way.
What is the EcoBoost Coolant Outlet Tube?
The coolant outlet tube is an often-overlooked component of the liquid-cooled charge air cooler (CAC) system found on the second-generation 3.5L EcoBoost engines.
-
Function: It carries coolant that circulates to reduce the intake air temperatures after turbo compression. This cooling is critical for preventing engine knock, maximizing performance, and maintaining efficiency.
-
Vehicles Affected: This exact setup can be found on 2013-2019 Ford Explorer Platinum and Sport Editions, 2011-2020 Ford F-150s, 2015-2017 Ford Expeditions, and various Lincoln models using the EcoBoost engine.
Why Does This Part Fail?
In many cases, the failure is a result of vibration and friction. In our case, the dealer failed to properly re-tighten the mounting bolts after a turbo replacement. This left the aluminum line free to vibrate and rub against the driver's side subframe mount, eventually rubbing a hole right through the aluminum and causing a massive coolant leak.
OEM Part Number: The part you will need for this fix is Ford OEM part number BB5Z-8A519-H.
Step-by-Step Replacement Guide
The outlet tube is located on the driver's side, running along the top of the subframe. Accessing it requires removing the inner fender liner.
Tools & Access:
-
Prep: Jack up the driver’s side and remove the front wheel. (For proper and safe jacking, review our guide: Stop Crushing Your Frame! The Exact 2017 Ford Explorer Jack Points).
-
Removal: Use a Phillips screwdriver and a trim tool to remove the plastic wheel well liner and expose the tube.
Disconnecting the Old Tube:
-
Hoses: At the rear of the tube, loosen the hose clamps on the two rubber lines and slide them off.
-
Quick Disconnects: At the front, disconnect the two quick-connect fittings. A set of pliers or a quick-disconnect tool will help if they are stubborn.
-
Unbolt: Remove the three 8mm bolts securing the support tabs to the subframe.
Installation:
-
Route: Carefully slide the old tube out and route the new tube around the CV axle into its final position.
-
Secure: Reconnect the rubber hoses and quick disconnects. Ensure the bolt holes line up on the subframe before tightening the 8mm bolts.
Pro Tip for Quick Connects: To prevent damaging the O-rings and ensure a smooth, leak-free connection, lubricate the O-rings inside the tube with a bit of clean coolant. Press the connector in until you hear a solid click. Watch the full video demonstration here for the precise technique.
🛠️ Final Steps and Product Promotion
Since this repair is critical to engine health, you need to ensure no damage was done while the engine was running low on coolant. An OBD2 scanner is essential for checking engine temperature and ensuring there are no hidden codes indicating a problem.
-
Final Check: Top off the coolant, let the engine run to operating temperature, and check the level again. Inspect all connections for leaks.
-
Diagnostic Safety: If your check engine light came on due to overheating or low coolant, use a diagnostic tool to read and clear the codes. We recommend having an affordable scanner on hand for all your EcoBoost maintenance needs.
Click here to buy an affordable scanner and other Diagnostic Tools! https://sellthoseflippingcars.com/store/diagnostic-tools
Watch the full step-by-step video guide: 3.5L EcoBoost Outlet Tube Removal – Ford Explorer Platinum DIY Fix