I was wondering if there are different styles of pinging and associated sound from each. I recently purchased a 1994 Geo Metro and have been fixing and tuning it up. The mileage is phenomenal.
I have never heard the “ting” or “pling” style of ping from my Metro but have heard it in other cars and a video illustrating ping in a G10 Metro. Larger displacement V8 and V8 engines have more of a metallic popcorn type rattle noise. I am pretty sure I had some light pinging today.
This sounded like a rapid light rattle under medium throttle and would go away at full throttle which seems like ping. It was very rapid like a machine gun but not nearly that loud of course. I don’t think I would have heard it had I had the fan blow on full. There was a slight loss of power when I heard this sound. I backed the timing off a bit when I pulled into the gas station and continued on without nearly this much of the sound or loss of power. I have a pretty good percentage of E85 in my tank and the rest is E10. My dist is now rotated slightly over halfway towards the bumper so more of the slot is visible towards the front bumper and not as much so towards the firewall.
I had been running the engine on run of the mill synthetic oil and switched to Euro synthetic oil once I figured the engine was going to hold together. It had been sitting a while and the rings were likely a little sticky and I think my compression has been coming up, causing me to have to back off my timing a bit. I need to check the timing on this with a light but does it sound normal to have the timing backed off this far? I thought factory was right in the middle of the slot and I am slightly more than halfway to the front bumper.
I seem to hear this sound for an instant and then it goes away. Are there different types of ping? I hear the terms knock, detonation, and ping used interchangeably but know they are different. I assume each makes a different sound. What would a rapid light rattle signify? I was wondering if it was normal to this engine but the fact it nearly went away when I reduced the timing tells me it is some type of pinging.