Engine "ticking" or "rattling"?

Bit of a thread revival, but I'm going to give this a shot.

 

I had this happen at 80k on 2008, 2.7 a couple weeks ago after an oil change. I thought it was bad fuel. Filled it with premium and a bottle of Lucas and it seemed to quiet it down. A couple days later the noise came back. I got a new filter (OEM) and 0-20 Mobil it again seemed help, but the noise came came back. I poored water on the belts and it is gone instantly. So I replaced the tensioner pulley. Still have the noise. It sounds like a timing chain or valves but it makes no sense coming and going the way it does. The water on the belts makes it go away so I am replacing the idler pulleys next. Then looking at the water pump. I am hoping it’s not a timing chain.

 

So finally did this fix. The sound is less pronounced, but still there.

 

Seafoam.

The bottle says to put 1 oz per qt. of oil in the crank case. The truck normally takes 4.5 qts, so that would be 4.5 oz.

I bought a cheap measuring cup at the dollar store to measure 4 oz and put it in the oil about 300 miles before the oil change. I only did 4 oz because I didn't want to overdo it and figured that was a good amount and safe in the event that some burnoff had occurred. The oil was very watery when I changed it, but the ticking sound was gone.

 

Yeah I know my old 2.7 ticked for about 10 seconds when it was cold out and around 300+K it was still ticking cold! Damn junk.