what is exactly a knock sound
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Think of a bullet ricocheting off a steel beam. Not as dramatic, but similar 
Also, pinging may be accompanied by power surging, due to timing being pulled.
jason
Also, pinging may be accompanied by power surging, due to timing being pulled.
jason
explanation is long and boring 
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If you're really knocking, you should feel some loss in power as soon as you hear a BB or two dropping into a coffee can. BTW, if you can hear it that distinctly, you are knocking a lot. Mild knock sounds like little static discharges. Some more severe knock sounds like a BB puncturing a coffee can.
Either way, even with mild knock, the ECU will pull timing, so if you're WOT and you hear real knock, you should feel some hesitation.
Either way, even with mild knock, the ECU will pull timing, so if you're WOT and you hear real knock, you should feel some hesitation.
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thanks jscoob!, so loss in power
also does knocking sound like when u turn off the car and its hot and you get that crackling noise in the engine???? similiar?
also does knocking sound like when u turn off the car and its hot and you get that crackling noise in the engine???? similiar?
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Yes, it can sound like the "tick tick" sounds of a cooling engine. Usually the stock ECU will pull timing and remember the knock event, so you shouldn't be able to repeatedly get knock under the same exact conditions...ie on the same hill, at the same RPM, same TPS and load.
Do keep in mind that to the human ears, wastegate flutter can be mistaken for knock. If you're car is bone stock, then wastegate flutter is hardly noticeable, so its probably not that.
Also, if you have bad gas, the car is trying to run as aggresively as it did before, but is painfully finding out that it is knocking - again the ECU will remember this and your car performance will suffer for a while, until the ECU slowly tries to be more aggresive again.
Do keep in mind that to the human ears, wastegate flutter can be mistaken for knock. If you're car is bone stock, then wastegate flutter is hardly noticeable, so its probably not that.
Also, if you have bad gas, the car is trying to run as aggresively as it did before, but is painfully finding out that it is knocking - again the ECU will remember this and your car performance will suffer for a while, until the ECU slowly tries to be more aggresive again.
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Originally posted by JScoob
Yes, it can sound like the "tick tick" sounds of a cooling engine. Usually the stock ECU will pull timing and remember the knock event, so you shouldn't be able to repeatedly get knock under the same exact conditions...ie on the same hill, at the same RPM, same TPS and load.
Yes, it can sound like the "tick tick" sounds of a cooling engine. Usually the stock ECU will pull timing and remember the knock event, so you shouldn't be able to repeatedly get knock under the same exact conditions...ie on the same hill, at the same RPM, same TPS and load.
I'd agree with your statement on repeated knocking... except that I've done it in a friends car. OwlBoogie had knock issues and I went by his place to see if I would give him a hand. We took it for a test and sure enough, on the gas, higher RPMs in 4th gear and twing twang ping pong (
). Go back to good driving habits for a minute and all's good. Get back on the gas and back comes the knock... and no surge. Go figure 
. This is why I stated "may pull timing". Honestly, though, I wish you were right.jason
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Originally posted by mmboost
That's a good description of the sound. Never thought of that before.
I'd agree with your statement on repeated knocking... except that I've done it in a friends car. OwlBoogie had knock issues and I went by his place to see if I would give him a hand. We took it for a test and sure enough, on the gas, higher RPMs in 4th gear and twing twang ping pong ( ). Go back to good driving habits for a minute and all's good. Get back on the gas and back comes the knock... and no surge. Go figure . This is why I stated "may pull timing". Honestly, though, I wish you were right.
jason
That's a good description of the sound. Never thought of that before.
I'd agree with your statement on repeated knocking... except that I've done it in a friends car. OwlBoogie had knock issues and I went by his place to see if I would give him a hand. We took it for a test and sure enough, on the gas, higher RPMs in 4th gear and twing twang ping pong (
). Go back to good driving habits for a minute and all's good. Get back on the gas and back comes the knock... and no surge. Go figure . This is why I stated "may pull timing". Honestly, though, I wish you were right.jason
What kind of mods and engine management is your friend running?
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