pinging or chain rattle

[CaptKirk]

How do I tell the difference??
My '01 sport trac sounded like pinging but then I was worried it could be the chain. So, I took it in and the dealer said it was pinging and they decarborized it and cleaned the injectors. Well, now it pings worse then before!
So, how can I be sure which it really is??
Thanks,

 

[CDW6212R]

Pinging is almost always associated with part throttle use while driving, under a load. Pinging doesn't happen while at idle, nor at a steady rpm and no load. You get pinging when going up a hill and 1/4-1/2 throttle. If you have a good tune up then it should be very easy to tell the difference.

 

[Bmwz389]

See I have the chain dragging sound right as i take off every time from 0...it goes away once i get higher into the 1st gear of the auto tranny....any clues to what that is? Seemed similar so I figured I'd ask =)

 

[CaptKirk]

What does each sound like? And why would it get louder and do it almost all of the time after they cleaned it out?
I had it loaded down today with a bunch of top soil and it pinging at 2500 rpm instead of 3000. And it did it all of the time not just when cold!
So, which is it????

 

[BWilliams]

Look at the Technician Corner board -- there's a TSB about timing chain rattle on the 4.0 SOHC. Sounds like the symptoms you describe.