Ford & Lincoln 3.5L/3.7L Internal Water Pump: The Hidden Flaw and Costly Repair (2012-2020)

The Critical Design Flaw: An Internal, Timing-Chain-Driven Pump

The single most important thing to understand about the water pump in the 3.5L and 3.7L naturally aspirated V6 engines is its location. Unlike most water pumps that are bolted to the outside of the engine and are relatively easy to access, this pump is located internally, behind the front engine cover (also called the timing cover). It is driven by the same timing chain that keeps your engine's camshafts and crankshaft synchronized. This design choice, likely made for packaging reasons in transverse (sideways) engine layouts, is the root cause of a common and extremely expensive failure. All vehicles covered in this guide share this transverse engine layout and are susceptible to this issue.

Vehicles covered by this guide include:

• 2012-2018 Ford Edge
• 2013-2019 Ford Explorer
• 2013-2019 Ford Taurus
• 2012-2019 Ford Flex
• 2013-2019 Ford Police Interceptor Sedan & Utility
• 2012-2015 Lincoln MKX
• 2013-2016 Lincoln MKZ
• 2013-2016 Lincoln MKS
• 2017-2020 Lincoln Continental

Symptoms of a Failing Water Pump

When this internal water pump begins to fail, it can present symptoms in two distinct ways: an external leak (the early warning) or an internal leak (the catastrophic failure).

1. External Coolant Leak (The Warning Sign)

Ford engineers designed a "weep hole" passage to give a warning when the pump's shaft seal starts to fail. Coolant that leaks past the seal is collected in a channel and directed out of a small hole in the side of the engine block.

• What to look for: A puddle or drips of orange or yellow coolant on the ground under the passenger side of the engine.
🎬 Watch: How to spot this RF corner antifreeze leak
• Specific Location: The leak will often run down the side of the engine block, appearing near or below the A/C compressor and alternator. You may need a flashlight and mirror to trace it back to the weep hole on the block.
• What it means: This is your final warning. The pump's internal bearing and seal are failing. The vehicle should be repaired immediately before the leak worsens or turns into an internal leak.

2. Internal Coolant Leak (Catastrophic Failure)

If the pump seal fails completely or the pump's main gasket gives way, coolant can leak directly into the engine's crankcase. This is the worst-case scenario.

• Coolant in Oil: The coolant mixes with the engine oil, creating a milky, light-brown substance often described as a "chocolate milkshake." You can check for this by looking at the oil dipstick or the underside of the oil filler cap.
🎬 Watch: How to diagnose a failing internal water pump
• Engine Overheating: With coolant being lost into the oil pan, the cooling system can no longer regulate engine temperature, leading to rapid overheating.
• Engine Damage: The coolant/oil mixture is a terrible lubricant. It will quickly destroy engine bearings, camshafts, and other internal components, often leading to complete engine seizure and the need for a full engine replacement.
• Timing Issues (DTC P0016): In some cases, as the water pump bearing develops excessive play, it can cause slack in the timing chain. This can throw off the engine's timing, leading to a rough run condition and a P0016 (Crankshaft/Camshaft Position Correlation) trouble code.

Known Issues, TSBs, and Recalls

Despite numerous owner complaints and several class-action lawsuits filed in the United States and Canada, Ford has not issued a recall for this water pump issue. Searches of the National Highway Traffic Safety Administration (NHTSA) database and for official Technical Service Bulletins (TSBs) show no specific documents addressing the water pump design flaw or offering a revised repair procedure for these vehicles. Owners are typically responsible for the full cost of the repair, especially outside of the vehicle's powertrain warranty period.

Replacement Difficulty & Procedure Overview

Difficulty Rating: 5 out of 5 (Professional Recommended)

This is one of the most labor-intensive repairs on these vehicles. The book time for this job is typically between 11 and 14 hours, but can take a skilled DIY mechanic several days.

The basic steps involve:

1. Disconnecting the battery and draining the cooling system and engine oil.
2. Removing the upper intake manifold, fuel rails, and valve covers.
3. Supporting the engine and removing the passenger-side engine mount.
4. Removing the serpentine belts and accessories like the alternator and A/C compressor to gain access.
5. Removing the harmonic balancer from the crankshaft.
6. Unbolting and carefully removing the front timing cover.
7. Locking the camshafts in place with special tools, then removing the timing chain tensioner and guides to get slack in the chain.
8. Unbolting and removing the old water pump.
9. Thoroughly cleaning all gasket surfaces.
10. Installing the new water pump and reassembling everything in reverse order, paying close attention to timing marks 🎬 See this step-by-step water pump replacement walkthrough and torque specifications.

Special Tools Required

This is not a job that can be done with a basic socket set. You will need several specialized tools:

• Camshaft Holding/Locking Plates
• Harmonic Balancer Puller
• Fuel Line and A/C Line Disconnect Tools
• Inch-pound and Foot-pound Torque Wrenches
• Engine Hoist or Support Bar

Buying a Used Engine Water Pump

The only scenario where a used pump might be encountered is as part of a complete used engine assembly. If you are considering purchasing a used 3.5L or 3.7L engine for one of these vehicles, inspection is critical:

• Check the Oil: Pull the dipstick and open the oil fill cap. Look for any signs of a milky, frothy, or light-brown residue. If any is present, the engine has suffered coolant contamination. Do not buy it. The oil should be dark and translucent.
• Verify Mileage: Only consider an engine from a low-mileage donor vehicle. The water pumps are known to fail anywhere from 50,000 to over 150,000 miles, so lower is always better.
• Check the Weep Hole: Inspect the area on the engine block behind where the alternator would sit. Look for any white or colored crusty residue, which indicates a past or present external coolant leak from the pump's weep hole.
• Best Practice: Even if a used engine looks clean, the safest approach is to factor in the cost of replacing the water pump and timing components before installing the engine into your vehicle. The labor is significantly easier when the engine is on a stand.

Cost Breakdown for Replacement

The cost of the water pump itself is a tiny fraction of the total repair bill. The majority of the cost is labor.

Frequently Asked Questions (FAQ)