Pinging or pinking is usually heard as a distinct rattling sound when you give the car
a lot of gas at low rpm's in a high gear. Not unlike the noise a paint rattle can makes
when it ia almost empty and you shake it vigorously. Or perhaps if you imagine several
very small people inside your engine with very small hammers pounding on the block
Usual cause is too much ignition advance for the fuel you are using. Loosen off the
bolts that hold the distributor in position and turn the dissy a fraction clockwise. About
1/8" of movement at the bolt should fix it. If you have a timing light and can see the
marks on the lower timing belt cover, you should see 15-17 deg advance at idle.