False knock? Looking for help.

[Einstein_nikola]

It’s just not a real possibility for me man but I hear ya. It’s true I could have barrels of E85 freighted to me and pump em in my garage but that’s just further than I’m willing to take it. We have no E blends or pump E anywhere, 100 octane is available but it’s $10 a gallon and I’d spend all my time driving cities over to it.

One day I’ll find it. Or not. You know

Did you ever find the knock issue or desensitized thr KR sensors?

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[dead_inside]

Did you ever find the knock issue or desensitized thr KR sensors?

I did resolve it but I couldn't tell you the cause. I threw a big round of more mods at the car in the hopes that just going through everything again would resolve it and it did. Sensors are still fully active. Being on pump gas, that was really important to me. I added the gen 3 intake manifold, OPG, 170* thermostat, headers, cat back, and a slightly smaller pulley. Now there is no knock anywhere in the RPM range and the car runs beautifully. This was farther down the mod hole than I wanted to go but the end result made it all worth it. I'm able to just drive the car now. I wish I could be of more help to anyone in this situation but there is already a metric ton of info regarding false knock with these motors, so I'm just a lucky one I guess.

 

[Einstein_nikola]

Mine its my headers, they almost touch, I need to replace mine im 100% it was your old exhaust manifolds that was the issue since you got headers tbh

 

[dead_inside]

Mine its my headers, they almost touch, I need to replace mine im 100% it was your old exhaust manifolds that was the issue since you got headers tbh

Exhaust is always the first thing to check according to most threads, so there is a very strong possibility you are correct. They were OEM headers without many miles on them and I beat them every which way with a mallet but nothing rattled. I also considered a runner in the intake mani could be an issue but if I was going to remove it to check, I figured why not replace it with a gen 3 mani. In the end, I love how the car drives and you could probably hear the sigh of relief from a state over when the knock was finally gone.

 

[Einstein_nikola]

I get knock only when Im at low rpms amd try flooring it, but when im at 3krpm and up no knock I get 20 or 21 of timing when I got WOT on 3rd gear, but if I try flooring it when im at 1.8k rpm i get knock up to +6 but when Im pass 3krpm I get -4.00 so thats how i know its definitely false

 

[K4fxd]

but if I try flooring it when im at 1.8k rpm i get knock up to +6 but when Im pass 3krpm I get -4.00 so thats how i know its definitely false

Low RPM is where it will knock.

 

[ZXMustang]

This was the source of my knock. Passenger side header touching the AC line. My shop was able to move the motor over a tad and get the clearance we needed. 22GT with TSP 1 7/8 catless headers.

 

[Einstein_nikola]

Yeah mines cleared, its the actually header of mine that the tubes are so close they resonate and make a ting noise that causes it, i putted metal clamps on it and they broke off but it did eliminate the knock tho! But it also dented my headers since they got hot so I said fuck it ima need new headers :( I got American racing catless headers

 

[Einstein_nikola]

Low RPM is where it will knock.

True knock no, false knock yes, real knock is when car is under load and causes detonation

 

[K4fxd]

True knock no, false knock yes, real knock is when car is under load and causes detonation

It's physics. All engines will knock easier at low RPM under load, more time for the flame fronts to collide. OP stated he got knock when he goes WOT at low RPM. So it is probably tip in detonation along with pre ignition.

 

[Cory S]

It's physics. All engines will knock easier at low RPM under load, more time for the flame fronts to collide. OP stated he got knock when he goes WOT at low RPM. So it is probably tip in detonation along with pre ignition.

Completely depends on Dynamic cylinder pressure. 1800rpm usually isn’t enough to knock with most FI systems. However, at 2900-3800rpm where the blower starts to build much larger cylinder pressure in the higher TQ window, is where most will start to see pre-ignition.

 

[Einstein_nikola]

It's physics. All engines will knock easier at low RPM under load, more time for the flame fronts to collide. OP stated he got knock when he goes WOT at low RPM. So it is probably tip in detonation along with pre ignition.

Actually I meant WOT at high rpms, when I just tap the throttle at low rpms is when I get knock, ive never gone wot at such low rpms since there no power there my bad.

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