Valve Springs Can Be Tightly Compressed Caution
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Valve springs can be tightly compressed. Use care when removing retainers and plugs. Personal injury could result.