Rocker Arm

WARNING: This page is about a different car, the 2003 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

Check the roller surface. If any dents, damage or seizure are evident, replace the rocker arm.
Check rotation of the roller. If it does not rotate smoothly or if looseness is evident, replace the rocker arm.

Fig 1: Locating Rocker Arm Seizure Out Roller Tip
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Check the inside diameter. If damage or seizure is evident, replace the rocker arm.