2011-2019 Ford & Lincoln 3.7L V6 Valve Cover Oil Leaks, Symptoms & Replacement

Vehicle Application List

This specific right (passenger side) engine valve cover is used on the 3.7L non-turbo V6 engine in the following North American market vehicles:

• 2011-2017 Ford Edge
• 2011-2019 Ford Explorer (Primarily Police Interceptor Utility models)
• 2011-2019 Ford Taurus
• 2011-2019 Ford Flex
• 2011-2017 Lincoln MKS
• 2013-2019 Lincoln MKT
• 2011-2018 Lincoln MKX
• 2011-2019 Lincoln MKZ

Symptoms of a Failing Valve Cover

When a valve cover or its integrated gaskets fail on these Ford and Lincoln models, the signs are usually obvious. The failure can be the main gasket itself becoming hard and brittle, the plastic cover cracking or warping from heat cycles, or the spark plug tube seals failing.

1. Burning Oil Smell

This is often the first and most common symptom. A leaking valve cover allows oil to drip onto the hot exhaust manifold or other engine components. This creates a distinct burning smell that you may notice inside the car, especially when stopped, or outside the vehicle after a drive.

2. Visible Oil Leaks and Grime

You may see wetness or fresh oil on the side of the engine, particularly around the seam where the valve cover meets the cylinder head. Over time, this leaking oil will attract dirt and dust, creating a thick, grimy buildup on the side of the engine block.

3. Oil in Spark Plug Wells & Engine Misfires

The spark plugs on the 3.7L V6 are located in tubes that pass through the valve covers. These tubes are sealed by small, round gaskets integrated into the valve cover assembly. When these seals fail, oil leaks into the spark plug wells, pooling around the spark plug and ignition coil. This can saturate the ignition coil boot, causing the engine to misfire, run rough, hesitate on acceleration, or trigger the Check Engine Light with misfire codes (e.g., P0300-P0306).

4. Low Engine Oil Level

A persistent oil leak will cause your engine oil level to drop over time, potentially triggering the low oil light on your dashboard. If the leak is severe, you may need to add oil between regular oil changes.

5. Oil in the Air Intake or on the Air Filter

In some cases, a problem with the internal PCV (Positive Crankcase Ventilation) baffle inside the valve cover can cause oil to be sucked into the engine's air intake system. This can lead to an oil-soaked air filter, oil pooling in the intake tube, and increased oil consumption. Ford issued a TSB (ASI-44354) related to this issue on the front (left) valve cover, but the principle applies to the PCV system as a whole. An updated valve cover design was released to address this oil pull-through issue.

Known Issues, TSBs, and Recalls

While there are no specific recalls for this valve cover, there are related Technical Service Bulletins (TSBs) for the 3.7L engine platform.

• TSB 12-1-17: Some 2011 Edge, MKX, Explorer, and 2011-2012 Mustang vehicles with the 3.7L engine built on or before May 1, 2011, could exhibit a ticking noise from the left-hand (front) valve cover area on a cold start. This TSB involves a repair to the camshaft caps under the valve cover.
• TSB ASI-44354: This bulletin addresses an issue on some models where oil accumulates in the PCV baffle of the front (left) valve cover and gets pulled into the air intake. The fix is to replace the valve cover with an updated part. While this TSB is for the left cover, it highlights a known design issue with the PCV system that can cause oil consumption.

Buying a Used Engine Valve Cover: What to Check

A used OEM valve cover can be a cost-effective and reliable alternative to an expensive new part, especially when compared to cheap aftermarket options that may have poor fitment. Here’s what to inspect before buying:

• Check for Cracks: Carefully inspect the entire plastic cover, paying close attention to the bolt holes and corners. These areas are prone to cracking from over-tightening or heat stress. A hairline crack will cause a persistent leak, even with a new gasket.
• Verify Flatness: Lay the cover on a known flat surface (like a countertop or piece of glass) to check for warping. A warped cover will not create an even seal against the cylinder head and will leak.
• Inspect Spark Plug Tube Seals: Look at the integrated round seals for the spark plug tubes. They should be pliable and free of cracks or brittleness. If they are hard and flat, they will not seal properly.
• Examine PCV Baffles: Look inside the cover at the internal baffles for the PCV system. Check for heavy sludge buildup or signs of damage. Excessive sludge could indicate poor engine maintenance on the donor vehicle.
• Confirm Part Number: Whenever possible, match the part number stamped on the cover to the OEM numbers listed in this guide to ensure compatibility.

Cost Breakdown for Replacement

The cost to replace the right-side valve cover varies depending on the part source and labor rates. The passenger side cover is generally easier and cheaper to replace than the driver's side, which often requires removing the intake manifold.

Replacement Difficulty

• Difficulty Rating: 2/5 (for Right/Passenger Side)
• Estimated Time: 1.5 - 2.5 hours
• DIY Feasible: Yes

Replacing the right-side (passenger) valve cover is a manageable DIY job for someone with basic tools and mechanical experience. The process involves removing the air intake components, disconnecting some wiring and hoses, unbolting the ignition coils, and then removing the valve cover bolts. The rear (driver's side) cover is much more difficult (4/5 difficulty) as it requires removing the upper intake manifold to gain access.

Frequently Asked Questions