Pinging and detonation

[95CobraStang]

I'm pretty sure I have never heard my car ping...so, with that said, i have no idea what it sounds like. Is it loud?? Is it quick and in even intervals?

I figure i should know this, since i have the predator and it is changing fuel and spark advance and i only have 91 octane.

If anyone could describe, that would be great.

thx

 

[DBMSTNG]

it can be loud or quiet, but usually you'll feel it if it's bad.

 

[3.8L_of_Pain]

It is kind of a fast, popping, crackling sound coming from the engine compartment. Sort of like Rice Krispies cereal: Snap, Crackle, Pop. Not a technical description, but you probably get the idea.

 

[Joel's98GT]

It is kind of a fast, popping, crackling sound coming from the engine compartment. Sort of like Rice Krispies cereal: Snap, Crackle, Pop. Not a technical description, but you probably get the idea.

good discription.

to original poster, have you ever been in a vehicle going up a hill at low RPM and it starts to bog down, and makes the sound discribed, but as soon as you down shift it goes away? i'm sure you have. that's detonation.

 

[twogts4us]

BBs or marbles in a tin tan, shaken repaidly...
If you hear ANYTHING from the engine after messing with timing, this would be it. You also lose power as this happens, but it's not dramatic (like when TC kicks in).
If you can visualize, as the piston is coming up during the compresion cycle, the A/F mixture ignites too prematurely and sends a sonic wave down the cylinder, essentially rattling the piston in the cylinder wall. Scary huh?
Increased octane decreases the votility of the fuel, therefore it's often prescribed for and effective in preventing detonation or pre-ignition.

 

[ChrisWorrell]

that is a very scary explanation of it

 

[95CobraStang]

good discription.

to original poster, have you ever been in a vehicle going up a hill at low RPM and it starts to bog down, and makes the sound discribed, but as soon as you down shift it goes away? i'm sure you have. that's detonation.

Ahhh i see. I've definatey heard that before. Thanks everyone for the descriptions as now ill be ready to diagnose a little detonation now.