knock sensor eliminator?

[zerodevil]

So, As part of my modding exploits i have found need to remove the knock sensors from the engine block (was planning to do this when i got my kennebell anyways.). I am removing because i need the extra room in my valley to fit a new manifold i have aquired, and with full knowledge that i am removing one of my vehicles engine safety features. My concern is if i need to make some form of eliminator, or if i am suck paying $700 for a custom tune.
In regards to making an eliminator, would it be as easy and cutting the existing wiring harness for the sensors and just wiring the ends of the four wires togeather (in the pairs that they goto the knock sensors) to show a full circut? or is there a measure of resistance that i need to fake as well? Knowing how the knock sensors opperate would be a huge step towards figuring out how to fake one.

thanks guys!

p.s. Transmission is still down and im waiting for TCI to send me a new torque converter.

 

[koda2000]

i don't think you want to be connecting any wires together. i'd think you just need to disconnect/unplug them. i'd be concerned that connecting the wires together would send a signal back to the PCM that there's a KNOCK condition which would cause your timing to be retarded. as far as how a knock sensor works, we used to test them by connecting a battery powered test light to the terminals and banging them on the parts counter. if the light momentarily lit, they were working.

 

[zerodevil]

Thats how i was thinking they functioned, but i have also heard that these things are so sensitive that they can detect a detonation at full RPM. Are these sensors engaged in active engine managment? If they are not and i will not throw any codes by disconnecting them i have no problem doing so. Has anyone does this yet?

 

[jayton]

Subscribing.

I will be trying to figure this out soon myself, as I have swapped a Mustang 4.6L cast iron engine from a 2003 model into my 2002 Explorer. The cast iron block does not have the raised bosses for the knock sensor, only the one in the center.

I had considered stacking the two sensors together on the one hole in the middle of the valley where Crown Vics/Grand Marquis mount their knock sensor, but they would be too tall to clear the bottom of the intake manifold. So I am now finishing my swap without a solution for the knock sensors yet. It seems other brands that I have researched such as Nissan or Jeep have been able to eliminate the knock sensors by using a specific ohm of resistor. I will be trying several different things, as I do not want to get a tune.

It would be nice if someone with a perfectly working Explorer could try unplugging their knock sensors now and report what happens.

From my reading, the way that the knock sensors work is that they are monitoring for a smooth varying pitch or hum. If that hum is interrupted, then a knock is registered and spark timing is retarded.

Since you are going with a blower anyway, I would think you would want to get a tune regardless of what your plans were on the knock sensors. Check out posts on here by a user rocket_5979, specifically http://www.explorerforum.com/forums/showthread.php?t=147212 That guy has big projects and gets them done. He does to all his vehicles like I do to all my computers, mod them to the extreme.

 

[Wills05xlt4x4]

i don't think you want to be connecting any wires together. i'd think you just need to disconnect/unplug them. i'd be concerned that connecting the wires together would send a signal back to the PCM that there's a KNOCK condition which would cause your timing to be retarded. as far as how a knock sensor works, we used to test them by connecting a battery powered test light to the terminals and banging them on the parts counter. if the light momentarily lit, they were working.

No way you can just unhook them...(im bet it wouldn't run;if it did it'd run horrid) There has to be a resistance to them. Otherwise everyone would just unplug them... my question would be if that resistance changes with RP M's or throttle input, or if it is indeed a constant resistance...
Maybe someone with tuning abilities like jah would be able to shed some light...

 

[zerodevil]

I am actually about to remove my manifold to replace the gaskets (have a slow leak off the back of the engine block), and while i am in there i will go ahead and unplug the knock sensor and see what happens. I am quite versed in the process of installing and removing the manifolds on my 2v 4.6 explorer so even if things go hay-wire i could have it pluged back in with out much difficulty in the span of about 4 hours. So pending us not hearing an answere from a "Tuner" i will provide at least one answere. The reason i am trying to dodge the "custom tune" bullet untill i really have to is there is only ONE dyno in town and for the license, 2 hours (min) of dyno time, and the tuners hourly wage i am looking at $700, it would be over $1000 if i did not already have my SCT x3. Rocket is a smart guy and i interacted a lot with him when i first got this truck, but didnt really have the funds to do anything substantial to it. I read your thread before posting here about this information, and if he says it should work with out a tune or an eliminator im willing to give it a shot, worst case is i get to plug it back in ^_^. Its probably going to be at least two weeks untill i have an answere for you, as right now i am waiting for TCI to return my waranteed torque converter (2500 stall), and then i need a weekend to get the transmission back in the truck. Im looking forward to the ideas that get bounced around in here!

 

[Wills05xlt4x4]

Good luck but my money says it won't start without them

 

[Limited02]

It should start without them, but it's possible it will knock. They are there for a reason...

Personally, I would tap into the block to remount them if possible. How are you so sure they are in the way of what you need to do? My dad swapped a 4.6 from a crown vic and there were two holes at the back of the black that he mounted them to. So when you open it up, see if you can remount to another hole or just tap for new ones.

 

[zerodevil]

Limited, does the 4.6 mustang mount knock sensors? and the 4.6l 4th gens done use them at all.. meh your probably right, while i was installing the correct flexplate yesterday i took a look and there is a great mouting space for each of them on the back of either cylender head, do you think that would be an acceptable place for mounting?

 

[Limited02]

I'm pretty sure the Mustangs(99-04 at least) do not have them. And yes, I also believe that is where my dad ended up mounting his knock sensors when he swapped in the new motor. I should be seeing him tomorrow, so I'll ask.

 

[zerodevil]

That would be a great piece of information! Looking forward to it guy, thanks .

 

[jah81592]

So, As part of my modding exploits i have found need to remove the knock sensors from the engine block (was planning to do this when i got my kennebell anyways.). I am removing because i need the extra room in my valley to fit a new manifold i have aquired, and with full knowledge that i am removing one of my vehicles engine safety features. My concern is if i need to make some form of eliminator, or if i am suck paying $700 for a custom tune.
In regards to making an eliminator, would it be as easy and cutting the existing wiring harness for the sensors and just wiring the ends of the four wires togeather (in the pairs that they goto the knock sensors) to show a full circut? or is there a measure of resistance that i need to fake as well? Knowing how the knock sensors opperate would be a huge step towards figuring out how to fake one.



thanks guys!

p.s. Transmission is still down and im waiting for TCI to send me a new torque converter.

Dont tie the wires together unless you want to have a fried pcm. You can simply disconnect them and pay for a tune to turn them off. For the life of me i cannot understand people putting money into hard parts and modifications then skimping on the MOST important thing which is going to hold the engine together. Save the headache and get a tune-regardless of who sells the device or writes the tune. If you simply relocate them you will still need to have the sensors either numbed or sensitized depending on the location to have them work properly.

There are a ton of Ford cars which don't have knock sensors. 1996-04 Mustang GT, 03-04 Cobras, 07-09 Shelby 500's. Roush turns them off on ALL the new 5.0L supercharged cars. Betcha didn't know that one. They are present and accounted for but the switch is off in the tune. The short answer is unplug them and turn them off in the tune.

 

[jah81592]

Here is a screen shot of a Shelby 500 that i tuned in the system switches section. Now this is only a switch not the values that tell the computer what to do. Think of it as the first layer then you get to the "meat" of the deal.-j

 

[zerodevil]

James thanks for some solid information! Id love to have you do the tune, my question lies in how accurate of a tune can you provide from a far? I assume you use data-logging and a few back and forth emails? After the transmission mods i had been planning on a new tune, but as you are aware there were a few mechanical issues that needed to get ironed out first.

 

[Limited02]

That would be a great piece of information! Looking forward to it guy, thanks .

I ended up not going home. So I am awaiting a response, but it's irrelevant because James told you what you need to know. You should be able to data log and get the info you need to James and he can whip you up a good tune. There are a few people that have done remote tuning sessions with him and have had great luck. I hope to be doing a session late this fall...

Edit: He said that on the back of the heads were some bolt holes not being used that were the same size as the knock sensor bolts. He attached them there and has had no issues since.

 

[zerodevil]

I would deffinately like to get a more thorough tune done by James. With all of my bolt ons and drive line upgrades i bet there is a lot of room for improvement at this point. I am hoping to get the brakes done in Oct, and then i should be free to spend some cash on a tune. I swear this truck is worse than a boat in terms of a hole into which one dumps money . The good news is i am running out of things to rebuild ^_^. If the transmission goes into the truck weekend after next it should still be in time for me to run it down the drag track before the snow hits.

 

[jayton]

Edit: He said that on the back of the heads were some bolt holes not being used that were the same size as the knock sensor bolts. He attached them there and has had no issues since.

The golden information I have been looking for. THANKS!

 

[Limited02]

I would deffinately like to get a more thorough tune done by James. With all of my bolt ons and drive line upgrades i bet there is a lot of room for improvement at this point. I am hoping to get the brakes done in Oct, and then i should be free to spend some cash on a tune. I swear this truck is worse than a boat in terms of a hole into which one dumps money . The good news is i am running out of things to rebuild ^_^. If the transmission goes into the truck weekend after next it should still be in time for me to run it down the drag track before the snow hits.

PLEASE DO!!! I've been waiting FOREVER to see what you can run so I can see how far off I am. And you are going to be getting snow in the next month??? I hope we at least get snow because last winter was the first winter I can remember never having to pull out a shovel.

The golden information I have been looking for. THANKS!

If you have any questions down the line, let me know and I'd be happy to help with what I can.

 

[zerodevil]

We usually get snow on the ground mid-october up here, but i think they close the track down near labor-day.