Checking Radiator Cap

WARNING: This page is about a different car, the 2006 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the radiator cap.

NOTE: Thoroughly wipe out the radiator filler neck to remove any waxy residue or foreign material.

Replace the cap if the metal plunger cannot be seen around the edge of the black rubber gasket.
Replace the cap if deposits of waxy residue or other foreign material are on the black rubber gasket or the metal retainer.