Like the subject says. The rattle has been slowly getting worse over the last several months. Today when I started it up after my 2nd stop, the rattle was way loud and I had very low power. I've been told camshaft and timing chain but it could possibly be the head gasket? My buddy and I replaced that a few years ago. He's a decades long airplane mechanic, I have faith in his work.

Other issues?

Took off the valve cover and found the issue. The guide lost the upper bolt and the chain had all sorts of slack. That rattle was the chain eating away at the inside of the block. Obviously an oil change is in order. But some 1/8" grooves shouldn't be too much concern should it?

The big issue is getting the guide secured back in place. I'm sure I need to remove the chain cover but would rather not. It looks like a could jam a piece of wood behind the guide and get the slack back... I'm sure the lower bolt might need tightening/replacing as well. Plus there's probably a loose bolt in there somewhere.

So here's the big question. I had help with the head gasket but learned a bunch from it. Do I tackle this project myself in the driveway or pay the $600 to have it done? The $600 comes with piece of mind and someone else's liability. What are the main things to be aware of when replacing the chain set? Timing marks and not messing up the gasket/RTV come to mind.

Just got an unexpected order for more than enough to cover the cost of the mechanic. I think I'll defer this time and get my truck back on the road ASAP! :-D