My car makes a low clicking sound when it climbs a gentle incline (usually when I'm on 3rd/4th gear). The sound does not come when I climb a steep incline (2nd gear).
The sound is a very inconsistent, very low sound (similar to a penny clicking on a glass). I can hear it only when I listen to it carefully. But, I'm pretty positive its coming from under the hood.
I usually use 87 octane gas. The sound SURPRISINGLY goes away when I use a 89 octane gas.
1) Can someone tell me whether there is a permenent solution for this problem?
2) Could this be engine knocking?
3) Will I hurt the engine if I continue to run it under 87 octane gas?
4) Will the engine be okay if I run it on 89 octane gas?
I would say that you have answered your own question. The 89 and 90 to 92 octane should not hurt the car. Sticking with the higher octane is okay. I highly doubt you will hurt the car on 87 octane but I would favor the 89 or above. Sometimes I thing that the oil industry will call it an 87 octane but it will be less.