timdastis

I just purchased an Accord last week knowing the knock sensor was bad (code 23) - I am not very familiar with auto repair but figured this should be an easy one to start - purchased the part and now ran into problems

First, I have no idea where it is - theres a photo on this forum floating around but I still can't seem to locate it once I'm under the hood

I took a couple pictures of what I see, if someone could help me locate this sensor it'd be appreciated - also I took a picture of some random harness thats not plugged into anything and a red wire thats not hooked anywhere - seems like this car may have some issues, but I really just want to eliminate the CEL to get it to pass inspection - thanks in advance for the insight

skracer13

The knock sensor is located underneath the intake manifold towards your #1 cylinder. Right below your injector. That red wire is probably your knock sensor wire. (Usually Pink/Blue or Red/blue) I wouldn't go buy a new sensor until you determine the one you have is bad. (sensor from the dealer is about $150) The only single wire in that region would be for your oil sensor or knock sensor. Oh the last picture you have up is where the sensor is at. (above the oil filter)

timdastis

so is it this piece?



any idea what the big harness should be plugged into (if anything?)

skracer13

Your image is blurry, that's kinda small it should be bigger here look at this pix. The big plug doesn't plug to anything.

timdastis

ok that makes sense - seems like its almost hidden by the oil filter (from underneath looking up) and i guess that red wire must belong to the knock sensor - ill check it out hopefully tomorrow and let u know but thanks for the help already

timdastis

ok I'm still struggling with this but think I may have found where it belongs - I took a bunch of photos up where I couldn't see and saw this bolt thats approximate to the size of the knock sensor





though this looks a little too close to the oil filter, i see nothing further up, shown here


that piece also looks like it could potentially be the KS but when i take off that harness piece it looks like the back end of a spark plug but smaller

I'm beginning to get irked by this whole thing just to pass inspection so again thanks for the advice in advance from a complete import noob

skracer13

The threaded hole with the plug is where your KS suppose to be, unscrew it (it's not a through hole or anything) and screw your KS into it. Concave your steel water pipe a little if you have to. Make sure you have a connector that correspond to your KS and I did confirm the wire is RED with BLUE strip (C3 connector at your ECM). I know your frustrated, but just try that. You can actually drill and tap a place near the cylinder wall to put your KS (way more advanced though).

timdastis

OK I finally got a chance to try and remove that screw - successful after a breaker bar

anyway as im unscrewing it I start getting dripped on by something - i see that its green so im assuming anti-freeze - at that point i got nervous and tightened the screw back

is that definitely the screw hole where the KS goes? i didnt want to screw anything up so i figured i'd come running back here for advice before i go ahead and finish the job

timdastis

bump - any advice?

timdastis

ttt

TheMuffinMan

iTrader: (1)

Remove the filter and look for the knock.

Do not just unscrew random things and/or drill and tap a hole in your motor. Shine a flash light downwards from the IM to help.

timdastis

I'm not randomly unscrewing anything - according to the alldata screenshot above and the screw I removed coordinate exactly - all I want to know is if anti-freeze is supposed to come out which you didn't mention - so any helpful advice would be appreciated

Thanks

TheMuffinMan

iTrader: (1)

Apologies, I posted while on a network proxy so your personal images didn't come up. Therefore I went solely on your info and unscrewing a bolt on the motor and having fluid come out generally is not a good thing

That does look like the correct placement for all the knock sensors I've seen. Do you see a harness dangling anywhere? It may have been tucked up under the IM.

I'll see if I can pull up anything

skracer13

Check PM

h22apwrdcivic

if you look in the right side of the screen directly above your oil filter that is your knock sensor. it will be easier to take off with the filter out of the way. it is usually a 1 1/16" socket or wrench to remove it...socket is easier.

hondamark35

i would have to disagree.. what you're pointing out is the oil sending unit.

you can see in this image the large circle is the oil filter mating surface, above that is the oil sending unit port, the other small hole to the left at the top is the place for the knock sensor. the bolt head on the lower left is the water jacket plug.

h22apwrdcivic

damn you are right, but look at his block it doesnt have the hole for the knock sensor. strange.

hondamark35

i see that. that is strange... could it be an F23A5 with a VTEC head? apparently the A5 didn't use a knock sensor, but i don't think it was VTEC.

h22apwrdcivic

i think he needs to purchase a block that has the proper hole b/c obviously his doesnt have it. that or he needs to do the make your own knock sensor trick i seen someone on here do with parts from radio shack. sounds ghetto but hey whatever works.

HondaPartsHero

there's also this method (from Cspeed racing for a Bseries block but maybe similar to F series?)



On a B18a block we chose to remove one of the mounting bolts for the alternator bracket and use this as the new location for the Knock sensor.



Using a 10.9 mm drill bit, opened up the hole on the bracket and the block. Then carefully tap the hole with a 12 mm x 1.25 thread pitch tap. Be sure to clean up the shavings and then screw the knock sensor. This will keep your ECU from throwing any codes.



Here you can see the knock sensor in its new location.

timdastis

Ok so it seems like I may have a different block than what actually belongs in it as OEM

I don't know if I have the guts/experience to start drilling into the engine block - is there any way I can just trick the car into thinking a working knock sensor is installed? The basic goal here is to get my CEL to go away so I can pass inspection - the car itself runs fine but I won't pass with the CEL lit

skracer13

You can try this here https://honda-tech.com/forums/forced-induction-16/knock-sensor-bypass-methods-part-numbers-1181854/

HondaPartsHero

What is the history of this car? What ECU is it running? Did someone swap in a new motor? Can you take a pic of the block stamp to see what block it is? Just seems odd that it would have a knock sensor code but no place for a knock sensor.

accord_raffi

This is what I was confused by, too.

timdastis

I just bought the car in April - had a clean title, drives great, good carfax/autocheck report but it seems like the seller may not have been completely honest - this is just my beater DD to get me to and from work and I pretty much stole it for the price I paid - it must have at one point had the engine replaced judging by all the comments on here - but i think it still is a vtec engine (i can feel it kick in around 4500 rpm or so)

Here are 2 pics of my engine - one is a label that may indicate the block type? i think it might be the tranny though not 100% sure - p2a8-2019404 are the numbers