I get a loud rattle noise when I start the truck cold for about 2 seconds. First I thought it might be from the valve lash adjusters bleeding down, but now the more that I hear it, I'm leaning towards the chain tensioners bleeding down. That's assuming they are hydraulic? The truck has 202K miles and runs fine otherwise. Any thoughts?

 

Well it depends on where the noise is coming from. If it is coming from the front of the head then I am going to say timing chain tensioner or chains.
Mine would make noise for a few seconds at first then it got worse and worse.
I replaced all the lifters last month and it helped a little.
I just ordered a chain kit and will start on the timing chains next weekend.