dustnbones

I'm looking at purchasing a 2014 GMC Sierra 5.3, with 250,000km. It does have a AFM delete. At operating temperature the truck sounds and drives smooth, no ticks. However, upon cold starts, especially very cold starts, it makes this unusual "clanking" kind of noise. I'll add the video of it. It start around the 14 sec mark, and goes on for a while before fading away as the truck warms up. This video was taken in the morning, at around -17C outside. I can't find anything similar anywhere on the internet so far... Anyone have any idea?! https://youtu.be/QDGHIQG1MU0?si=tAoQ2uxSIHWks3Ms