This sounds like pinging or as the English like to call it, "pinking". It
would depend more on load than rpm. Possible culprits could include too low
octane fuel, maladusted timing and carbon deposits in the combustion
chambers. If it happens while accelerating, engine speed 2,000-3000 rpm,
then that is probably it. The way to tell for sure is to buy a tank of
premium, and see if that makes it go away.

The first thing to look at, is whether the octane fuel you are using is up
to your car's minimum requirements. My 1999 Civic requires 86 octane, but
around here one can buy 85 as "regular". The second thing is to clean the
combustion chamber deposits out of your engine. One way is a fine water
spray into the intake, while the engine is running, but maybe that is best
left to your mechanic.

Earle

> wrote in message
ups.com...
> I have a engine ping or knocking sound (kind of like a gurgling
> metalic) sound from my engine
> that seems to occur at specific rpm ranges. It has happened on and off,
> mostly in the summer. The car has 180K, I take it to a trusted mechanic
> and do all of the 15,000 mile maintenance work recommended by honda,
> including oil changes every 6k.
> Before taking it to the mechanic, is there anything cheap I can try?
> Thanks
>