slight knocking sound

[steellll]

i have a 93ATX with a slight knock(ping) at around 2500 RPM's. it only does this when i'm driving the car real easy / higher gears with little gas.
the car has a rock solid idle, no check engine lights, pulls really hard and runs great.
it kind of sounds like the same noise my dodge pick-up with a 4.7 V8 makes if i put regular gas in it.
i tried holding 2500 RPM in neutal in my garage, no noise. i tried putting it in gear, foot on the brake, 2500 RPM, no noise.
just when i'm driving easy.
any ideas?

 

[dpsutphin]

I assume you are using premium fuel. If not, that could be the problem. Even if you are, if it came from a non-major brand company, for example from a privately owned convenience store, it might be only labeled premium.

You should not have an octane related ping at 2500 RPM in any gear. I would suggest a fresh tank of premium from Exxon or Mobil, or someone like that, with some good quality fuel injector cleaner.

But I also realize the ATX is a different animal from my MTX, perhaps it is something transmission related that someone with the same drive train can shed some light on.