what's an acceptable knock reading?

[91tsi2wd]

I'm just curious what an acceptable knock reading would be? Obviously none is ideal, but I logged a reading of 14 today at 11.7% injector duty at 3187 rpm. Just a little wot rip to 4 to get a little spoolup to hear it with my new intake. If it makes any difference, on the same pull, at 4375 rpm with a 3.9% injd, I logged no knock, that is when I let off....is this dangerous?

Oh I'm at 15 psi too...

 

[yokotabrat]

Like you say, less knock is better, however the thing to look out for the most is when does the knock occur. The injector duty cycles you are posting indicate you're getting knock during low load conditions (cruising, idle, or letting off the gas). These usually aren't a big concern since cylinder pressures are already low and damage is most likely not going to occur (not that you should ignore it, though). When you should be most concerned with knock is under WOT and high load conditions, or when getting knock for extended periods of time like during a hill/mountain climb.

The most important question you should be asking yourself is why are you getting knock. According to what you are saying, it's most likely occurring during or near closed loop operation and low load. It could be fuel trims being fully railed, phantom knock from some mechanical noise (lifters, etc), or even a bad tank or gas. If you have more info on when you're seeing knock, post up and we can try to help get rid of it.

 

[rst95eclipse]

To me, the most acceptable knock count is zero. But that's just me.

 

[Spooling99]

If you are seeing knock while not under boost, I'd suspect you might have a case of phantom knock. You could try getting a new knock sensor or checking the torque on your current one. If the knock sensor is still the original one that came with the car I'd check it.