My 96 jimmy has been lightly pinging for years but about 6 weeks ago it seems to be noticeably worse (and loses power). Maybe it's because the temperatures hotter? It happens on the highway going up hills around 60mph and it goes away if I give it more gas to unlock the torque converter. I have no check engine light. Using 89 Octane makes it run much better, but I don't think I should need that. Should I spring for the dealer injector flush or should I just get better fuel?

 

This problem can have more than one cause. A dealer can tell the source by hooking up their scanner.

 

As rriddle said said:many possibilities here...Usual cause:carbon bulid up in the intake and combustion chambers(heads) Using a different type of fuel will not remedy this issue. It has been my experience that a thorough intake cleaning has worked for others using the various products out there(seafoam etc) and while I have never used seafoam or like products,I have found the best remedy to be a 5 or 6 hundred mile road trip while using Marvel Oil in the fuel and work the motor! 1,000 miles using a good oil based additive worked in my 97! 2 and 1/2 years and no more pinging! Continue to use Marvel at every fueling,and can run 87 octane with no issues! Just a thought!

 

my 90 runs lean, always has so during the winter it slightly pings during acceleration and hills. good ol expensive premium gas fixes the problem. i just got back from a 400 mile trip and put premium in it to be paranoid and the truck never ran so good. i dont know how that will effect newer vehicles though