Ticking noise from engine

'97 Safari, V6, 2WD Auto trans w/overdrive, having intermittent ticking noise coming from engine. The noise can be very pronounced, then settle to a "soft" ticking and then disappears completely. The truck has been taken to the garage twice and both times the ticking noise had stopped. Any insight as to what is causing the noise?

lifters

Yea, probably valves and lifters... mine does the same thing, but the engine runs smooth and has plenty of power.

Mine ticks too. turned out that it was the fuel injector bulbs doing their job. At idle speeds they click open and shut constantly, makes a tick tick sounds.

Yea my 89 did that to, I recomend buyins some Oil Detergent. I bought this stuff at my local Shuck's called CD-2 Oil Detergent, i put it in after i changed my oil, havent heard the noise yet and its been out 2 month.

I get a clicking noise from mine to every now and then and it is the tensioner needed to change the belt it was stretched to far