Help! Truck developed a weird "knock" sound...

[Jason]

Fixing to do injectors and turbo on my truck, moved it out of the garage the other day and was greeted with a new/strange noise. I've got the video of it on my phone, can't get it to upload on YouTube to post it...if anybody can help me, shoot me a text and I'll be happy to send it to you to listen! Wasn't planning on tearing this motor down but I'm scared I may have to now!

Thanks
Jason
254-733-8698