Got a noise that showed up recently (145K mileage). It sounds like "dieseling" or rattling a box of nuts. It only happens with acceleration or throttle demand.

I've changed the spark plugs and they look pretty good (I can snap a pic if needed) and cleaned the intake.

Is this valve noise suggesting adjustment is needed (never been done)? Or is it crummy gas? Or What???

Thanks in Advance
Andrew

 

Check the timing first.

Did you get the same temperature range plugs?

 

Same plugs as previous. I use the NGK stock plugs. The noise was occuring even before the plug change.

Andrew

 

Is it kind of like a ticking noise, something like this:

http://www.marko3xl3.com/sounds/ (click on either one)

If so, that's normal for high milage 3.4L, it just comes. It's usually more pronouced once the truck warms up. Most people say it's the valves that need to be adjusted, but some have tried and it didn't cure the problem. For now, I wouldn't worry about it unless it becomes more noisy, at which point it's probably time for a valve job. If it's the fuel injectors, they'll just do that 'cuz they are old as fart, they still run perfectly fine tho. If you want to confirm where it's coming from, get a mechanical stethoscope or use the poor mans type (screwdriver butt to ear, tip to whatever) to check.