blazer engine knock

[rd]

Vehicle is 1994 s-10 blazer 4.3 v6. 117K I got it about 40K ago.
If I start without block heater any temp under about 30 get a knock that begins a few seconds after it starts. Knock/tapping stays until well warmed up. Live in ND so it has been cold . After 25 mile trip home from work . Not a sound of the knock.
What is you best guess? Is it going to self destruct on me?
Oil last couple of changes is Quaker State Synthetic.

 

[CBDFrontier06]

Without hearing it in person, I'd say you have a lifter that isn't pumping up like it should. I had this issue with an old Chevy 2.5 that stopped when I replaced all the lifters.

 

[mechtech2]

Bad lifter or worn rocker/ pushrod. A good lifter may click if there is too much clearance for it's self adjustment mechanism.