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  • Writer's pictureDerek Huther

Everything About Valve Covers & Valve Cover Gaskets

Ahhh, the notorious valve cover! You may have recently learned that the valve cover and/or valve cover gasket on your vehicle needs to be replaced. Well, what the does that even mean? Below we will go over everything about valve covers and valve cover gaskets.

What does a valve cover do?

A valve cover seals the top of an engine. Below is a photo of an engine without one. As you can see, without the valve cover, an engine's internals are exposed to everything. The cover stops debris and dirt from entering the engine, which would be detrimental if they made their way in! The valve cover also keeps oil, which is under pressure inside an engine, from exiting. An engine needs several liters/quarts of oil in it all all times. If not, internal components will break, overheat, and the engine can seize.

Engine Without a Valve Cover

Engine Valve Cover (Goes on Top of the Engine)

What does a valve cover gasket do?

The surfaces where the valve cover and engine meet are not perfectly even. As a result, when the two components are mounted together they form small gaps. A gasket will sit in between these two components to create a tight seal. A gasket is usually made of rubber, cork, or plastic. This makes it fairly flexible, and it allows it to easily form and fill gaps, when pressed between the valve cover and the engine. The seal created by the gasket keeps harmful materials from entering the engine and keeps oil from leaving.

Valve Cover Gasket

Valve Cover Gasket (Zoomed in)

What happens when a valve cover or valve cover gasket fails?

  1. The oil level runs low. This will damage, overheat, and even seize an engine.

  2. Oil enters unwanted areas, such as spark plug tubes. This will make an engine run inefficiently and cause it to misfire.

  3. Sludge builds up inside the engine. This occurs to vehicles that have oil separators in the valve cover.

  4. Oil lands onto hot components and burn. This creates a strong odor and even smoke.

  5. Oil grime builds up throughout the engine bay.

  6. A whistling noise appears while the vehicle is running.

  7. More smoke, than usual, comes out of the vehicle's exhaust.

  8. A check engine light appears.

Valve Cover Gasket Leak

Why does a valve cover or valve cover gasket fail?

A valve cover & valve cover gasket are constantly exposed to intense heat, debris, and the outside elements. Over time the valve cover will crack and break, while the gasket will shrink, dry up, and crack. It is very important on higher mileage vehicles to replace the valve cover at the same time as the gasket. When a gasket fails, many times the valve cover will follow. This is especially true on many modern vehicles with plastic valve covers. At times, the damage to the valve cover is internal and not visible from the outside. Hence, why it is important to do both the gasket and the valve cover at the same time.

Choose Bavarian Auto Repair to do the repair! :)

-Factory original parts. We only use parts that came on your vehicle from the factory.

-2 year / 24,000 mile warranty on parts and labor

-ASE certified mechanics. We have the same mechanics found at your local dealership

Links to photos used:





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