5th gear ping or just a rattle?

[spederman]

I cant tell if its pinging or just a rattle. It doesnt always do it either, but when im on the highway and in 5th gear, and try accelerating from 50 or 60mph, it sounds just like pinging. but then it doesnt do it every time i drive the car even on the same tank of gas, so its kinda confusing. Ive always used 93 octane from reputable gas station companies.

Anybody else experience this?

 

[twogts4us]

Likely it's pinging, given the circumstance you are providing. 5th gear acceleration is tough on the engine, trying to pull from very low RPMs against tall gearing.