Yukon knocking noise?

[sams60gmc]

Hey guys I'm new to this section of the forum, I'm usually hiding out in the 60-66 board. But anyways I've been having this problem with my truck (04 Yukon), when it gets close to my oil change like within 500 miles it starts making some loud ticking/banging noises from the top end of the motor, kinda sounds like a diesel, it only happens when the motor is completely cold and happens for about 5 minutes til the motor starts to warm up. My Dad and I think its a stuck lifter or something up in the valves, any ideas? What about adding some sort of additive to my oil? The truck only has about 70000 miles on it and runs perfect after the knocking dies down. Thanks for the help.