Knock Sensor: Different cars work, Money Saver!
09-24-2010, 09:09 PM
#1
Knock Sensor: Different cars work, Money Saver!
Alright. I posted this thread https://www.s2ki.com/forums/index.php?showtopic=818390 About how I broke my darn knock sensor. I was pretty mad, but not as mad as I was when I found out it was $150.00, with my discount!
Well many told me that you need a dam S2000 Knock sensor, and nothing else is compatible. I am doign soem research to see if a '03 Civic Si Knock sensor will work.
The Part number is. 30530-PPL-A01 SENSOR, KNOCK . Almost all Honda knock sensors start with 30530, but that does not mean they will work. I had the dealership order me one from a 2003 Honda Civic si. ( I have a good dealership, good guys, Fox Honda Grand Rapids Mi )
The green one is my broken S2000 knock sensor, the gray one is my new one from the '03 civic si . They are both the same, and there is not a difference minus the color, here are some pictures for you all, sorry I took crappy ones!
Well many told me that you need a dam S2000 Knock sensor, and nothing else is compatible. I am doign soem research to see if a '03 Civic Si Knock sensor will work.
The Part number is. 30530-PPL-A01 SENSOR, KNOCK . Almost all Honda knock sensors start with 30530, but that does not mean they will work. I had the dealership order me one from a 2003 Honda Civic si. ( I have a good dealership, good guys, Fox Honda Grand Rapids Mi )
The green one is my broken S2000 knock sensor, the gray one is my new one from the '03 civic si . They are both the same, and there is not a difference minus the color, here are some pictures for you all, sorry I took crappy ones!
09-24-2010, 10:05 PM
#2
Most knock sensors are tuned to the frequency of the knock expected for the engine its designed for. This helps reject other mechanical noise.
The knock frequency depends mostly on the bore diameter and to a lesser extent the chamber shape and compression.
Do you know if the grey sensor has the same acoustic and electrical characteristics as the green one?
The knock frequency depends mostly on the bore diameter and to a lesser extent the chamber shape and compression.
Do you know if the grey sensor has the same acoustic and electrical characteristics as the green one?
09-24-2010, 10:16 PM
#3
Originally Posted by chris_barry,Sep 24 2010, 10:05 PM
Most knock sensors are tuned to the frequency of the knock expected for the engine its designed for. This helps reject other mechanical noise.
The knock frequency depends mostly on the bore diameter and to a lesser extent the chamber shape and compression.
Do you know if the grey sensor has the same acoustic and electrical characteristics as the green one?
The knock frequency depends mostly on the bore diameter and to a lesser extent the chamber shape and compression.
Do you know if the grey sensor has the same acoustic and electrical characteristics as the green one?
09-25-2010, 12:13 AM
#4
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I think chris_barry means the bore of the cylinder (and diameter of the piston of the engine).
A faulty knock sensor circuit gives a P0325, that's about the wiring (and the control circuit on the ECU?), not about how it works acousticly, I think.
There is no CEL for a "knock detected at the wrong load / revs" as far as I know.
There is also no CEL for "knock detected and I've changed the ignition / injection"
Maybe stand-alone ECU's can show what signal it gets from the knock sensor when there is knock, that will show the acoustic differences between the 2 you have.
Why would Honda produce identical (mechanical size, threads & acoustic) knock sensors and use 2 different colours?
One would think the colour is a warning: Look out, same dimensions but different acaustic operating parameters.
Let us know what you find.
A faulty knock sensor circuit gives a P0325, that's about the wiring (and the control circuit on the ECU?), not about how it works acousticly, I think.
There is no CEL for a "knock detected at the wrong load / revs" as far as I know.
There is also no CEL for "knock detected and I've changed the ignition / injection"
Maybe stand-alone ECU's can show what signal it gets from the knock sensor when there is knock, that will show the acoustic differences between the 2 you have.
Why would Honda produce identical (mechanical size, threads & acoustic) knock sensors and use 2 different colours?
One would think the colour is a warning: Look out, same dimensions but different acaustic operating parameters.
Let us know what you find.
09-25-2010, 05:00 AM
#5
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Ohm them out to see if they are different. you may be able to ping them with a screwdriver, while connected to an ohm meter, and determine some differences.
09-26-2010, 03:13 AM
#6
The resistance check wont show any difference in the centre frequency.
Only way is to apply a step noise to them and use a spectrum analyser to look at the more sensitive frequency band.
Just so people understand, A 82mm bore engine will product a knock frequency around 7 KHz. A large bore like the F20C is more like 6khz.
Most of the frequency sensitive knock sensors have a window around plug or minus 500 Hz either side.
If the substitute sensor was tuned for 7 KHz, and your engine was knocking at 6Khz the ECU is not going to see any noise. It wont post a check engine light as it does a continuity check to make sure a sensor is plugged in. It just can't tell if its the right one or not.
The sensors also have different sensitivity. If you got one with the right frequency band, but it was much more or less sensitive its also going to mess with the knock detection by the ECU.
If the bores of the engines are similar you will probably get away from it.
From what I've seen the K20A and F20/F22C all use the same knock sensor ( green one)
Only way is to apply a step noise to them and use a spectrum analyser to look at the more sensitive frequency band.
Just so people understand, A 82mm bore engine will product a knock frequency around 7 KHz. A large bore like the F20C is more like 6khz.
Most of the frequency sensitive knock sensors have a window around plug or minus 500 Hz either side.
If the substitute sensor was tuned for 7 KHz, and your engine was knocking at 6Khz the ECU is not going to see any noise. It wont post a check engine light as it does a continuity check to make sure a sensor is plugged in. It just can't tell if its the right one or not.
The sensors also have different sensitivity. If you got one with the right frequency band, but it was much more or less sensitive its also going to mess with the knock detection by the ECU.
If the bores of the engines are similar you will probably get away from it.
From what I've seen the K20A and F20/F22C all use the same knock sensor ( green one)
09-26-2010, 03:42 AM
#7
The original S2000 Knocksensor is the only one that works with the ECU and its Knock-Tables.
I've tried to look for alternatives myself long time ago, because this shitty sensor is ridiculous expensive in Germany (180,- EURO!!).
But there's no way to use a different one.
The Bosch-Sensors are better and lot cheaper (for around 40,-EURO), but I didn't figured out how to change the Knock Tables in my Hondata K-Pro yet. The K-Pro is a modified Integra RSX ECU, it should work with the Integra Sensor also. But I didn't find any infos on the Hondata site concerning Knocksensors or -tables. So I had to buy the golden Honda Knock Sensor with enriched uranium inside
BTW, here is a good article with some frequency investigions:
http://bigmoose.deviantmethods.com/b...ages/knock.htm
I've tried to look for alternatives myself long time ago, because this shitty sensor is ridiculous expensive in Germany (180,- EURO!!).
But there's no way to use a different one.
The Bosch-Sensors are better and lot cheaper (for around 40,-EURO), but I didn't figured out how to change the Knock Tables in my Hondata K-Pro yet. The K-Pro is a modified Integra RSX ECU, it should work with the Integra Sensor also. But I didn't find any infos on the Hondata site concerning Knocksensors or -tables. So I had to buy the golden Honda Knock Sensor with enriched uranium inside
BTW, here is a good article with some frequency investigions:
http://bigmoose.deviantmethods.com/b...ages/knock.htm
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09-26-2010, 08:31 AM
#8
Originally Posted by chris_barry,Sep 26 2010, 03:13 AM
The resistance check wont show any difference in the centre frequency.
Only way is to apply a step noise to them and use a spectrum analyser to look at the more sensitive frequency band.
Just so people understand, A 82mm bore engine will product a knock frequency around 7 KHz. A large bore like the F20C is more like 6khz.
Most of the frequency sensitive knock sensors have a window around plug or minus 500 Hz either side.
If the substitute sensor was tuned for 7 KHz, and your engine was knocking at 6Khz the ECU is not going to see any noise. It wont post a check engine light as it does a continuity check to make sure a sensor is plugged in. It just can't tell if its the right one or not.
The sensors also have different sensitivity. If you got one with the right frequency band, but it was much more or less sensitive its also going to mess with the knock detection by the ECU.
If the bores of the engines are similar you will probably get away from it.
From what I've seen the K20A and F20/F22C all use the same knock sensor ( green one)
Only way is to apply a step noise to them and use a spectrum analyser to look at the more sensitive frequency band.
Just so people understand, A 82mm bore engine will product a knock frequency around 7 KHz. A large bore like the F20C is more like 6khz.
Most of the frequency sensitive knock sensors have a window around plug or minus 500 Hz either side.
If the substitute sensor was tuned for 7 KHz, and your engine was knocking at 6Khz the ECU is not going to see any noise. It wont post a check engine light as it does a continuity check to make sure a sensor is plugged in. It just can't tell if its the right one or not.
The sensors also have different sensitivity. If you got one with the right frequency band, but it was much more or less sensitive its also going to mess with the knock detection by the ECU.
If the bores of the engines are similar you will probably get away from it.
From what I've seen the K20A and F20/F22C all use the same knock sensor ( green one)
09-26-2010, 10:35 AM
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Originally Posted by hecash,Sep 26 2010, 08:38 AM
I'm going to watch this topic over the long haul. I just put a few names into a spreadsheet to keep track. I'll pop up when a piston comes through the side of the block from time to time.
I'm glad someone is getting scientific with this instead of just going with what feels right! Also cheers to the ones willing to put their motors on the line to save 80 bucks.
09-26-2010, 11:25 AM
#10
Originally Posted by triddle,Sep 26 2010, 10:35 AM
I'm glad someone is getting scientific with this instead of just going with what feels right! Also cheers to the ones willing to put their motors on the line to save 80 bucks.
Also the K20 and F20.. are as close as you can get, so I wouldn't see there being a huge difference. Honda-tech has members using b18 knock sensors, with no issues.
Coming into this tread saying we're doing something wrong, but you can not back it up is pretty ignorant.
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