This started within the past couple of weeks, and I haven't had money nor time to really look into what the problem is. Once in awhile when I start the truck (4.2L V6) it makes a ticking noise, and it'll eventually go away. Sometimes it'll last 10 minutes, sometimes 30 seconds. Sometimes the tick is more severe than others. Starting yesterday upon revving or accelerating it vibrates real bad, but only sometimes. I took a video earlier.. take a listen. I've gotten what seems like 50 different answers from people, so I'd like to know what ya'll think. I know whatever answer I hear, I won't like so just lay it out.

 

I hate to bump the topic, because I know how annoying that is (I frequent other forums), but I'm going to... with an update though.

I ran the truck pretty hard today, purposely doing jerky accelerations just to open it up a bit, and it still ticked once in awhile. I go to start it this afternoon and it starts cold with no tick at all. I thought I was just lucky, but I started it again over an hour later, reading cold and no tick again. I'm not sure what that means.

 

Alright.... it's been awhile. Somebody has to know a thing or two about this. Any insight on the issue?

The rattle heard in the video while revving is the exhaust.. it's gotta be remounted toward the rear.

 

could be your valves

 

Exhaust leak.