My 1995 T100 pings at right around 2000 rpm when encountering a incline at highway speeds. Pushing harder on the gas doesn't cause the pinging to increase - as a matter of fact it goes away almost totally. The symptom is more pronounced when the a/c is running.
The pinging isn't heavy, just noticable. The truck has 280,00 miles totally and 40,000 on a new short block that the dealer installed last year.
Does anyone have any ideas why this is happening and what to look for in the way of knock sensor, egr, etc? It runs well otherwise and I'd really hate to have to buy more expensive gas just for this reason.
Thanks all.