Engine Valve Cover Seal

What Is an Engine Valve Cover Seal?

Sitting between the valve cover and the cylinder head, the valve cover seal ensures oil stays inside the engine to lubricate the rocker arms and valves, while keeping dirt and debris out. It's a small component that carries enormous responsibility — without it, the junction between the valve cover and cylinder head would allow oil to escape and contaminants to enter, both of which spell trouble for engine longevity.

The cylinder heads contain an engine's valve train components — valves, valve springs, and rockers — which continually actuate to control the distribution of intake air into each cylinder, as well as the release of combustion gases into the exhaust tract. The valve cover seal is the first line of defense protecting all of that precisely engineered motion.

Why Valve Cover Seals Matter

The valve cover seal serves three critical roles: sealing and containment (keeping motor oil inside the top of the engine where it lubricates the camshafts and valves), contamination prevention (stopping road grime, dust, and moisture from entering the delicate valve train), and vacuum maintenance (helping maintain the engine's internal vacuum pressure through the PCV system, which is vital for engine efficiency).

A worn or leaking valve cover gasket can cause oil to escape and allow debris and small particles to enter the space between the pistons and cylinder, resulting in friction and increased wear and tear. The escaping oil also means that engine components will receive less lubrication and may begin to grind against each other, putting more stress on the engine and shortening its lifespan.

Signs of a Failing Valve Cover Seal

Catching a failing seal early can save significant repair costs. Watch for these common symptoms:

• Visible oil leaks — oil pooling on top of or around the sides of the engine, often accompanied by a burning oil smell from oil dripping onto hot exhaust components.
• Engine misfires — the engine may not run smoothly due to insufficient lubrication, and oil leaks can reach the spark plugs, causing misfires and performance issues.
• Low oil level — the engine may start to run low on oil, causing friction and increased engine temperature, which can ultimately lead to engine failure.
• Dirty valve cover — oil leaks can absorb dirt and debris under the hood, which hardens on the valve cover or cylinder head.

What to Look for When Shopping

In the past, gaskets of this nature were constructed from pressed fibre or cork of varying thicknesses. Today, the vast majority of automotive gaskets are made of rubber-coated plastic or specialty fiberglass compounds. Modern silicone and molded rubber seals generally offer superior durability and resistance to heat cycling compared to older materials.

Visually, a lower-quality seal may look very similar to a high-quality seal appropriate for a given engine platform. However, a lower-quality seal with insufficient heat-resistance will harden and crack prematurely and will not work as intended. Always confirm vehicle-specific fitment and material compatibility before purchasing — the right seal for a daily commuter may differ from what's needed for a truck that sees heavy towing or off-road use.

Top Brands for Engine Valve Cover Seals

Crown Automotive is a go-to source for Jeep and Chrysler platform valve cover seals. Crown Automotive offers the largest line of replacement parts for Jeep®, as well as a growing line of parts for Chrysler & Dodge. Their valve cover seals are original replacements made of the same silicone construction as the factory seal, and their molded replacements are made custom and do not require any modification for installation.