shudder problem. help please.

hey guys, recently i have been having a shudder problem with my truck. when im sitting at an idle i can really feel it, but it comes and goes... it has it's mild and severe days. my truck has 143,000 and some change on it, and i just did an oil change. bought the truck new, so i've taken it through it's paces, but i havent beaten it badly any time recently. kind of concerned about it. considering taking it in, but i dont want to get bent over by toyota of orange. someone in my emt class said it feels/sounds like a timing or compression issue. there is a mean clicking noise you can hear outside of the engine compartment, but i've had that for quite some time, possibly even when i bought it... should i be concerned? i know it's hard to diagnose over the internet, especially since you can't be there to witness it first person... BUT, any help or suggestions would be greatly appreciated.

 

Ticking is pretty common on these trucks. I'd maybe change plugs if you don't know how old they are also.

 

spark plugs, check!
i didnt know autozone did diagnostics... (shows how niave i am...) thank you!!