Valve Guides
WARNING: This page is about a different car, the 2004 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.
Using a micrometer and bore gauge, take diameter readings on valve stems and guides to check stem-to-guide clearance. Be sure to take reading at more than one place along the length of each stem and guide. If clearance exceeds limit, replace valve and valve guide.