As it says. i have another thread about some "diesel" noise im getting from the motor and i threw the code maybe once in the past 2 weeks, then today it went off 5 times after id restart the car. i just changed the oil yesterday and i have CP 9:1 pistons OS, Ealge H beam rods and new bearings. anyway does this code most likely just represent the slight "knocking" im getting from the motor? and why would it just pick up on it so badly today? also could it be a faulty knock sensor? damn im so confused and frustrated, any help would be great, thanx in advance.

 

come on now

 

did you check your wiring? maybe its loose.

 

The ecu's program is only able to detect knock from the stock engine configuration. It is tuned to the characteristics of the motor from the factory, internals is gonna mess dat joint up son.
-PHiZ

 

ok so basically i can expect to get this since im getting a light knock sound at idle? anyone else experience this with forged internals? im trying to figure how serious this light diesel sound is and how serious this CEL is. thanx guys

 

I can't remember exactly, but doesn't the timing come into play too? If the timing is off.. and your valves touch the pistons .. wouldn't that cuase the knock sensor to trigger too? curious too...

 

i know i checked the timing twice since the install three weeks ago so i dont think that could be it, but thanx for the info...

 

What about your cam timing. Have you checked that? Also remember if your running a higher compression now you'll have to use higher octane fuel to help keep pre detenation at a minimum. Do you have any more specifics? Like what are you running for fuel octane and whats your ignition timing at? And is the 9:1 your actual compression ratio? can it possibly be higher? Is the knock sensor a one wire setup? One thing to consider........if the sensor and wiring is indeed good then there's a problem. Cause the sensor is indeed detecting a detenation concern that is real. Just cause you did stuff to the engine doesn't mean you ignore that sensor cause its job is to detect detonation and that detonation will be the same between a stock angine and a modified engine the only thing that will change is the perameters that the detonation takes place. If everthing is working correctly that code needs to be adressed cause detenation can blow up your engine in extreme situations, and suppressing the detonation (spark knock) is done the same way with any engine.

 

im running premium, which is 93 here in chi town. also the timing is set at stock, my bro did that so i dont know the exacts on that. also im pretty sure im not detonating, in fact im pretty sure its throwin the code cause of the piston slap or something, i used to have 11.5:1 comp in there and ran the same gas and never threw this code. also yes my compression should be right at 9:1 as thats the pistons i put in there. wat else...lets see, the car seems to run just fine, smooth with nothing odd other than the light knocking sound at lower rpms...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dr.Auto &raquo;</TD></TR><TR><TD CLASS="quote">that detonation will be the same between a stock angine and a modified </TD></TR></TABLE>


Changing out the internals changes the acoustical properties of the block. The honda KS is not sophisticated, and is a very basic safeguard against knock. It is not like the KS you'd find on a DSM or WRX, that was specifically designed for FI or forged applications.
-PHiZ

 

Ok so is this normal at all? Do i just need to keep restarting the car? Also will anything change once i start boosting it? As i said its just NA built now while i pull together the kit. Should i expect any changes after i boost it? (other than the obvious)

 

if its just the knock sensor thats bad or something, is it normal at all for it to come on and off at random times. ex.. ill drive it like for a week with no code, then in one day it will come on 5 times.

 

I realize what effects internals have on block acustics and I also realize there are different types of sensors. What I'm trying to say is spark knock is delt with in the same manner as any engine. And changing the internals will not change how the detonation is delt with, just the extremes at which will be nessessary to eliminate it.

Make sure the knock sensor is tight!!!!!!! Not loose in the block cause just vibrations will set DTC's all day long. There is also a testing precedure for the sensor, but the easiest way to see if it's bad is just replace it with a known good one and test drive under the same peramiters. Also if its more than a onw wire set up simply a open circuit will set a DTC so check the wiring for chafing of shorting to ground. If it's just a one wire typically an open circuit will not set a DTC because a knock sensor is a voltage emmiting sensor(untill recently) meaning it only makes voltage when its detecting a detonation. A onw wire sensor if open circuit or shorted to ground will never see voltage at the ECU and never actually know if pre-detonation is taking place. Which typically when the ECU is changing the ign timing to crazy extremes and still not seeing a signal from the knock sensor it may trip a DTC. On the other hand being shorted to power somehow the ECU will constanly see a signal of abnormal magnatude and set a DTC. Given your description of intermmitant issues I would lean towards the KS being ok and your experianceing a wiring issue. More importantly make sure the possible intermittant connection isn't at the connector for the KS and make sure all wiring in the engine bay is ok. You know how it goes when your taking out a engine and you find another wirs you forgot to disconnect. I'm not saying that happened but it's possible and the wire could have been damaged.

 

just want to post a problem I had with KS.

Mine seemed to come on just like you said, every now and then, some days a lot, some days not at all.

Turns out the actual KS was loose under the intake manifold. I tightened it up and have never had a problem since.

maybe it's something not so complex. try easy stuff first.

 

thanx for the replies and experience guys, im gonna give both those ideas a try here this weekend sometime...im hoping its just a lil loose in there and needs some tightening. ill keep ya posted

 

well i kept getting the code, but only after the car ran for more than 15 minutes, never earlier. Anyway i decided to throw the car up on a lift today at work and discovered the sensor was loose. Like it was loose enough that i could untwist it by hand. As impossible as it was to get to it with a tool, i tightened it as much as i could, which still isnt prolly as much as it needs. Im hoping this was the problem and i wont keep getting the light, any thoughts or experience with this? Thanx guys.

 

if you're hearing a diesel noise, then If i'm not mistaken that's your Rod's that are knocking. It should not sound like diesel!!

 

Actually with forged internals the diesel sound is usually piston slap, does the sound subside after the engine warms up? If so its piston slap which isnt uncommon with forged int. If it doesnt go away then I'd check what everyone else has suggested.

 

Well after like weeks of asking and researching ive discovered that some noise is somewhat normal, and in fact the noise seems louder after its warm cause its much louder at like 750rpms, and it doesnt drop that low till its warm. The sound is definetly there, and i drove my car today for like an hour straight with no code, so im assuming it was the sensor itself, just really loose. Im kinda waiting for it to warm up here and get my turbo on and see what the engine sounds like then, hopefully it will change somewhat, if not, then let there be boost.

 

wel it just came on again today, ****. oh well maybe its a bad sensor or some ****, im hopin it just came loose again or somehting.