Plenum Gasket

The Plenum Gasket (also known as the Intake Manifold Gasket or Caterpillar Gasket) is a paper/rubber gasket that creates a seal between the upper intake manifold and lower intake manifold.

Replacement

When pulling the intake manifold, this gasket is almost always damaged or destroyed. It is extremely fragile, and practically impossible to re-use without creating a vacuum leak. Given the labor required to remove the intake manifold and the inexpensive cost of this gasket, it is highly recommended that it be replaced every time the intake manifold is removed.

Caterpillar Gasket

After gathering enough food, many intake manifold gaskets will find a safe spot to hide, then begin weaving themselves into a chrysalis. After several weeks, the chrysalis is broken and the metamorphosized butterfly valve emerges. This is why intake manifold gaskets are sometimes referred to as "caterpillar gaskets."