my 1995 isuzu rodeo with 189,000 does it sometimes and then it will go and go and not make a sound. I cant stand it when it happens to tick and someone hears it and says your truck sounds awful dont you know it needs oil? I think in my head no it doesnt!!! Now I become so annoyed I tell people watch out it may blow

I made some videos of my engine under various circumstances. If you listen you can hear the hydraulic lifters and/or the hydraulic tensioner:

http://forum.planetisuzoo.com/viewtopic.php?p=204843#204843

Have you replaced your timing belt tensioner?