Coolant or dirt on the belt, or pulleys, will make some strange noises...... usually it will wear off in a little while. How does your belt tensioner feel? Can you tell a general area where the sound is coming from?

 

What's the milage ? Is your truck low on oil ?

 

113000 miles ya its got oil....sounds like is coming from around the Tb area

 

Have a look around the engine when it is dark,engine running... see if you see a light show.

 

Also the almost stalling on idle after you let off the gas is air in the system. After I did my recent thermostat I had air trapped in the system around a coolant temp sensor and it caused the same issue. Burp the cooling system very well and that issue will be fixed. I couldn't really hear the tick but like HeyYou said dirt or moisture on a pulley or belt will make some strange noises. Almost sounded like the injectors.

 

Sometimes the evap solenoid cycling will throw me off, makes me think I'm hearing an engine tick. On mine, it's located on passenger side fender.

 

Thats so random I got my truck back from the shop today (for an axle hsg) and while it was there they but a tstat gasket in and it has a knock as well I will take video

 

so last time my truck sat it stalled out a couple times as well when i first began to run it again (sit for like 3 or 4 days). so that may just be why it stalled. (for starters my battery is a group 25 not a 27) so today after i got it from the shop it was acting up and stalled out and the engine was making a knocking noise. so i parked it the front tires on the curb popped the radiator cap and let that bitch run for a couple min. than the noise whent away so i put the cap back on and drove home. I would try to burp your system and check your battery

 

well its been burbed very well now drives the same no power loss...still hav tht weird tick tho

 

what temp thermostat did you put in? ive heard of people putting in 180 degree with no sct and having issues. Guys could it be something caused from the thermostat itself???