For the last several thousand miles I've heard pinging during the slightest acceleration especially below 2000 rpm when I can hear it during suburban driving when engine sound echos off curbs and walls.I usually use Arco preminum,occasionally try Chevron with techroline,with little difference.Being concerned about serious engine damage after extensive consideration I decided to start by replacing the 80,000 mile old iridium spark plugs.This procedure has been delayed due to the claimed 104,000 miles service interval of replacement from the Nissan Maintence manual.Driving technique has reduced pinging by accelerating briskly to a higher rpm similar to a manual transmission using my auto tranny in manual mode.Having this car 15 years in the Calif east bay manual shifting is just too much chore.I've been delighted to find replacing the spark plugs has reduced pinging to a level that I'm no longer concerned about engine damage.I'm again totally stocked with my Z committed with achieved 200,00 miles without serious troubles, currant mileage186500miles.I expect this post will be of little importance to the street racer sect out there,to me this has been the best car i,ve owned .Having read of poster experiencing pinging below 2,000 rpm I wanted to share how easy it was to substantially reduce it.

 

Have you completed all other maintenance? I complete mine way ahead of schedule and can totally tell there is a difference. I don't follow the maintenance manual since the recommended interval is at the point where the fluid or part is closer to potential failure.

 

Surprised to hear that a change of spark plugs reduced pinging, usually caused by too much ignition timing or inferior fuel.