95 silverado problem?

yes, i have a 95 silverado that has 107,000 miles and recently when i start the vehicle it has a slight ticking or cluttering noise which sounds like it is coming from the left side of the motor. It only does it until the truck gets warmer. What could it be.

does it sound like a pencil being tapped? if so it's probably a bad lifter. GM has a product called lubricity that works pretty good on sticky lifters. you might need to adjust the valves too.