I just recently discoverd my 80 pings a little when under load . To be more specific, we noticed it while wheeling this past weekend. I was in low-low and climbing up a steep hill, at the initial throttle and low RPM, I could just hear it out the window. My buddy whom was standing outside could hear it clearly. This morning on the way to work, I could hear it. Typically I have the stereo on, and the exhaust and tires are so loud I can't hear anything anyways. I've always thought it might just be exhaust rattle on some mornings. My question of course, how long could this pinging have been occuring and what's the possible harm to the engine or other components? A few details: 117,000 miles on a well maintained rig. 1997 FZJ80, normally aspired, runs mobil 1 full-synth 10w-30 since 70k miles. I always run cheap regular fuel (costco gas) from California. I'm going to add the Chevron Techron Fuel Cleaner system for the next few weeks to see if I get any improvement (if the issue is caused by excessive carbon buildup). Along with a possible increase in octane hopefully this will be resolved. Has anybody else discovered this while running regular 87 octane?