I've been told it's like dried peas or small rocks rattling in a tin can, but how loud is it? Does it (the rattling) get faster with increasing RPMs?

I hope I haven't been hearing it and ignoring it, just because it doesn't sound like my idea of rattling peas.

 

like a marble dropped onto the valvecover

 

So it's only a one-time occurance, meaning you only hear one ping at a time? Or is it continuous?

 

I've always heard it as "empty spraypaint can". If you get a rattly tinny racket when you push the loud pedal, especially if you're running FMU or other hacks, that's pinging.

If it's just one "tick" ignore it; pinging is more like clattaclattaclattaclatta until you let off the gas.

 

I see, so it's based on load, not RPM.

 

click clack clack click clackclack click clack ( not in that particular order). Loud enough to hear very well over my exhaust and lack of interior at high rpms. Yes, unless you're on the gas, it won't do it.

 

Yes, it is most always related to load. But then you can't produce boost without the engine being under a load.

 

Continuous.

Sometimes very, very rapid, like a mini machine gun on fast-forward.

 

imagine...a rattle can hitting a rev-limiter?

 

I'm trying to decide if I'm pinging or not. It only happens under full throttle, full boost, and probably above 5500rpm. It almost sounds like the cowl shake I get over bumps, but much faster. It's not very loud, however. About the same volume as cowl shake.

I always run 92 or 93 octane, base timing at 14 degrees, but I also have the Bipes, so it's at, I think, 6 degrees under full load.

From what I'm hearing, it sounds like it may be pinging, but it doesn't seem loud enough and it doesn't strike me as metallic. Seems more like plastic vibrating.

Maybe my 18 year old ears are just too sensitive, I'll gladly take that as an answer.

 

Look at the plugs... they'll tell you the truth.

Mark

 

its hard to hear especially in loud cars like Miatas. It also isn't always continuous and can be somewhat random, but will usually happen under full load around the torque peak or higher.

 

and yeah, looking at the plugs will tell a lot. If the plugs are greyish with a "pepperd" kind of look it can often mean slight detonation, but not always

 

Best way to check the plugs is to shut the car down as soon as you hear it. Then the color of the plugs will show you what was happening right then, and it doesn't give them a chance to color-over. Get on an empty strech of road, rev it up, if you hear the noise, cut the engine, coast to a safe spot to pull a plug, examine the color.

 

Yeah, that pretty much sounds like pinging...I mean, if it's only happening on heavy throttle/heavy load, that's a pretty good indication

Usually torque peak is when you'll hear it first, right at ~4500 RPM.

 

Just pull the timing back a few degrees more and try it out. Agreed that pinging usually onsets at torque peak, but just the same, it sounds like pinging from your description.

 

when my ex-tuner f'd my civic up he was running 26 advance on it and i still heard no noise... lasted about 4 hours of driving on boost untill enough material was blasted off of my head and pistons to finally start making little compressed chunks of aluminum and that eventually stuck in a few of my valves and caused my engine to die from not allowing the valves to close. i heard nothing and i had a baaaaad case of predet. to say the least he is deffinetly making it up to me. appearently timing maps from the honda sohc motors are not swapable to other honda sohc's :gay: