What is acceptable knock

[240dreams]

Alright, i just installed my safc2 and i i turned up the boost and just realized that the knock sensor is giving me some odd readings. Im not sure if its ok or not. I get like 40 knk at idle and it goes closer to 0 when accelerating. Is this normal? if it isnt what should my knock sensor be reading safely at? Thanks for the response in advance.

[ziggy682]

That's exactly what my SAFC 2 did before somebody broke into my car and stole it. I figured it was pretty normal for a KA because they run kind of rough at idle. Mine would always drop back to 0 over idle.

[240dreams]

thats not cool man. i got the black one - kinda harder to see from the outside. do u have any idea if this is safe?

[240dreams]

alright after driving around, knock went down. its around 0-6 during regular driving. im seriously deadlocked on this. i dont want to mess my engine up. someone please reply with some info.

[uno]

mine does the exact same thing man...sometimes knocks in the 40s during the hot days but under accel it's 0-10

then on cool nights it's usualy 0-1 all the time...i think it's normal...i was just searching for the same kinda question you asked.

[14.5drift]

uno, if you want to keep it you should definatly figure out what the problem is. Over 16 is undisirable and desearves some attention, 40 needs a tune asap

[14.5drift]

to thread starter 4-6 counts is pretty safe

0 is ideal, but not always possible, lol

[uno]

why would it only do it when it's 90 outside ? i have heard from other people that it's mainly false knock....

[uno]

also i am not burning or losing any fluids at all.

any ideas on what it could be? i think personally it's a bad knock sensor, because under throttle it's 0 and too, i can turn the car off for 5 minutes, turn it back on and the "knock" count is below 10 again

[14.5drift]

Unbelievable. What the hell is false knock?

Nevermind, I'd look into some better meters where you dont need to worry if you are destroying your engine or if it only seems like you are, lol.

if it's happening when it's hot out, it likely isn't "false knock", I would say off hand not knowing any about your car or tune, sounds like your intakes are just getting too high, there are a few remedies to sort of use as a band aid, 1) octane booster might help supress the knock in the hot weather as well as a bigger intercooler or 2) pull back the timing some

But I dunno exactly, I just know a 40 count is very high.

[uno]

False knock would equal i.e. loud stereos, headers banging the car, Upper chain guide banging around, etc.

but whatever

ok well i'll push the timing back some....i was told by local nissan dealer that anything under 100 was acceptable....but maybe they don't know. what exactly am i band aid'ing ? i've driven it this way for 2 years....so honestly what do you think it is?

[14.5drift]

Do you have a loud stereo, a head banger, or upper chaing bangin around?

I dunno either, I am not a pro, I am just kinda being a parrot you know?

I read some thing about this the other day, and that is what the guys were saying......

[uno]

that's cool, i've just never thought anything about it tho...because i have no smoke in the exhaust, no fuid loss and i still have very good power, no metal in the oil...nothing at all...i don't have anything you listed, but i do have a broken motor mount, if not both so that may have something to do with mine....i wish i could find out what's up with it? any other ideas man?

[MaxType 240]

Anything over 100 is bad. I've had occasions where I've hit past 200 but that's during dyno testing.

I've had as high as upper 50s under street driving conditions, but not often.

Jesse

[14.5drift]

Wow! maybe I am way off base uno, the dsmers on http://www.dsmtuners.com were discussing this just the other day, and they all had stand alone set ups some pushing over 300 whp. I figured even though they are different motors the effect of knocking in the engine would still be the same but apparently not.

Crazy

[C-Kwik]

All knock is bad. Though, I'd make sure the knock sensor is working properly. Perhaps test the sensor according to the FSM. If you have detonation, you will likely hear it. Turn down your stereo, open your window, and make a 2nd gear run. Perhaps next to a center median where it can echo off the median and allow you to hear it even better. But it won't be necessary.

[uno]

cool guys, thanks for the input, even tho we kinda hijacked this guy's thread, but i think the questions got answered

14.5, i thought i read somewhere about the under 100 thing bein ok, but i definately wasn't for sure , cause it sounds wierd since my friends wrx doesn't knock any at all the whole may through. i think it's just nissans and or their knock sensors. i am gonna check mine soon, because i think when it's hot out, my knock sensor goes crazy. but to the thread started hope this helped and any more info is appreciated

[240dreams]

its all good.