[RESOLVED] How I resolved my knock/ phantom knock

[viprez586]

So i tried everything, torqued at 14ftlbs, different locations, its own personal ground for the casing, race gas.


I would get phantom knock while in neutral free-revving with hard throttle stabs and when i would go WOT.

What i tried, a metal washer in between the sensor and the block: Actually made it more sensitive( maybe trying different size thickness and diameter would yield different results.

Telfon tape on the threads: No difference.

Welding the hole on the inside of the threads (1gs): Slightly less sensitive, took harder throttle jabs to get knock.

Finally i decided to try a telfon washer(thickness of turbo bolt washe) between the sensor and the block, i know this has the possibility of deafening the knock sensor completely but i tested it before it went on the road.
Very hard quick jabs would result in about 18-24 counts of PK which was better than my previous maxed out 43.
So i figured okay lets give it a test, i kept boost as low as my spring can go(14.7psi aka 1bar).

1st gear i'd pull in the 12-20pk, 2nd-5th showed 0-3 counts of knock WOT timing at around 18-20 tuned at 10:1 AFR.

I'm currently in the works of testing this further, posting some logs, and more details to come. Comments welcome. I know its another damn thread about knock but maybe some greater detail of phantom knock will reduce the overjam of "why am i getting knock" threads.

 

[Black_Bullet]

So i tried everything, torqued at 14ftlbs, different locations, its own personal ground for the casing, race gas.


I would get phantom knock while in neutral free-revving with hard throttle stabs and when i would go WOT.

What i tried, a metal washer in between the sensor and the block: Actually made it more sensitive( maybe trying different size thickness and diameter would yield different results.

Telfon tape on the threads: No difference.

Welding the hole on the inside of the threads (1gs): Slightly less sensitive, took harder throttle jabs to get knock.

Finally i decided to try a telfon washer(thickness of turbo bolt washe) between the sensor and the block, i know this has the possibility of deafening the knock sensor completely but i tested it before it went on the road.
Very hard quick jabs would result in about 18-24 counts of PK which was better than my previous maxed out 43.
So i figured okay lets give it a test, i kept boost as low as my spring can go(14.7psi aka 1bar).

1st gear i'd pull in the 12-20pk, 2nd-5th showed 0-3 counts of knock WOT timing at around 18-20 tuned at 10:1 AFR.

I'm currently in the works of testing this further, posting some logs, and more details to come. Comments welcome. I know its another damn thread about knock but maybe some greater detail of phantom knock will reduce the overjam of "why am i getting knock" threads.

A teflon washer?

I recently was posting about using teflon tape on mines and setting it at a looser torque spec and most of my pk went away... But then again, I was getting no were near as bad PK as you mentioned.

The only problem I have with desensitizing the KS, is that you dont really know how much your desensitizing it by, and I dont want to not register real knock and not detect it, even though theoretically real knock sould be strong enough to carry thru some teflon washer/ tape etc.

Being able to tune your timing/ fuel helps a lot in attempting this in the first place since you should know what kind of tune is within reason for your motors longevity.

I think your 10:1 afr is way too rich though ( maybe it was just for testing purposes)
but ive found my car to get knock from going richer than 10.4 AFR when running any kind of boost/ timing. Not to mention the back firing; Read- "Rich knock"

That sounds good about your results though; definitly sounds like your acceleration will improve since your timing advance will be closer to their full values.

 

[viprez586]

Well i suppose its more of a fiber/ rubber washer, i just found whatever was laying around in the garage.

Yeah my AFR is pretty rich but i don't really see any adverse effects, i guess i will try to lean it out some and see how things go.

 

[JayRolla]

Adverse effects are your losing power. You can get a lot more out of the car with a leaner afr I would say around 10.9-11.1.

 

[viprez586]

Yeah by adverse effects i meant rich knock, tuned to 11:1 today and felt a little bit better on the butt dyno.

 

[viprez586]

*Update*
After a couple of months the teflon/fiber washer hardened and deteriorated due to heat cycles and I'm back to square one.

My KS i orginally started with was one from Advanced auto parts. I felt it may be defective.

So ongreenperformance.com has OEM KS for $60+shipping. Upon arrival indeed OEM part(E001T15075) in the Mitsubishi box.
I installed it with some little washers that have a rubber o-ring in the I.D.
Tightened it to hand tight and still get PK with hard jabs, and now it seems PK comes on only when my external gate opens up to the ATM.
Low boost (under 10psi) it's fine.
I have noticed my light throttle/little or no boost phantom knock has significantly decreased.

I'm curious if my external WG dump is causing PK because of noise, or the fact that it's crushed in a few spots, either way I want to run it out the bumper because it's currently dumping right above the front crossmember.

Over the next couple days I'm going to try different torque on the sensor, different number of washers, and the original washer i used the first time to temporary "cure" PK.
Also I'm going to be ordering some piping for my external gate dump tube.

Comments, thoughts, ideas welcome.

*EDIT*
Forgot to add, I had 1g lifters the whole time(F...U Kar King!), replaced them with 3g lifters that have like 200miles on them so that's not it either.

 

[Stainbox12]

Im subscribing to this thread. This is most commonly known in 1g cars. The real reason is unknown. I currently grounded the knock sensor, so it won't detect knock. I know its a bandage but, the car was undrivable. I tested a lot of things and none yielded positive results. A definite fix i believe is to get a chip from jeff, which has a code and it eliminates PK.

 

[viprez586]

My last resort is getting a chip/dsmlink because i don't have an Eprom ECU.
After tightening the KS today and yielding little to no difference I feel like this will be the only route.
I'm hoping to reroute my Ext. dump tube today however and hopefully that will make a difference.

 

[tunethis]

I had this problem with my 94. It would get phantom knock while reving in neutral. I didn't have an A/C compressor so, I bolted it down there. It still registered a count or two when I accelerated with a cold engine. I did this because I drove a lot on the highway and it would get 43 counts while cruising and it killed my gas mileage. I really enjoyed how the car pulled after that.

It was a temporary fix but, I would definitely go with a chip to handle the PK issues. Especially, if you can't figure it out.

 

[JayRolla]

Im subscribing to this thread. This is most commonly known in 1g cars. The real reason is unknown. I currently grounded the knock sensor, so it won't detect knock. I know its a bandage but, the car was undrivable. I tested a lot of things and none yielded positive results. A definite fix i believe is to get a chip from jeff, which has a code and it eliminates PK.

So did you exactly ground the KS? Did you just run a wire off the harness to the chassis? i want to eliminate my KS so I dont have PK issues. I see knock even with e85 running good afr and 15psi. If I release the throttle I can usually get a good run but a lot of times I will still see knock when I know it shouldnt.

 

[Stainbox12]

So did you exactly ground the KS? Did you just run a wire off the harness to the chassis? i want to eliminate my KS so I dont have PK issues. I see knock even with e85 running good afr and 15psi. If I release the throttle I can usually get a good run but a lot of times I will still see knock when I know it shouldnt.

Yes i ran a wire from, the threads of the knock sensor, to the chassis. Make sure obviously that the sensor its connected to the block. Im in the process, of getting a wideband and tune that way without knock. I know its not recommended and its just a band aid fix, but hey, there's no way to deal with this PK issues apparently without a chip.

 

[JayRolla]

Even with a chip you can still get PK at high rpm. I want to do this because I run e85 and shouldnt have to worry about knock as long as I stay within reason.

 

[Stainbox12]

Even with a chip you can still get PK at high rpm. I want to do this because I run e85 and shouldnt have to worry about knock as long as I stay within reason.

Well man, if you think you are PK at high RPM, then good luck finding the reason. a lot of people can't even find the reason for parth throttle knock or phantom knock, now at high rpms.

 

[JayRolla]

I know the reason. Its a too sensative crappy 1g KS. But for some reason the 7 bolts dont really have the issue.

I mean I think it has to be PK. I have seen 15 counts at 5500rpms at 10 psi and 22* timing on e85. I should see no knock at that level. On my bro's car ive tuned 30psi, e85, 24* timing and never a blip of even 1 count of knock.

 

[BoostFrenzy]

I know I don't have a 1g, but there is a local around here that is having the same exact problem with his 1g so I am subscribing.

One question I have, what about guys who have done a 6-bolt swap? Do they have the same problem with PK? If not, what parts would be different between the 2 KS setups? (Obviously the ECU, but what else?). If, as Jay has stated, the 1g 7-bolt engines don't have this problem, what's externally different (sensors, wires, pullys, w/e) between the 1g 6-bolt and the 1g 7-bolt? If there is nothing changed between them besides the 6-7 bolt kinda deal, it may all come down to harmonics.

For all that are posting WITH PK, it may be useful information to post what is done to the car in terms of engine internals as well as if you have eliminated the balance shafts or have done something with other rotating parts.

Good luck guys.

 

[dsm-onster]

The 2g knock sensor is different. It reads differently than a 1g sensor so it cannot be used in conjunction with a 1g ecu. This is probably the difference that makes a 1g more prone to knock than a 2g. Perhaps the 1g sensor is too sensative. Also a 2g ecu doesn't read knock below a certain rpm and TPS percentage.

 

[JayRolla]

I have a 93 that originally had a 7 bolt and now has a 6 bolt. Still have the PK issue.

 

[toofast82]

let me know if you guys do any eprom editing, i have codes to eliminate pk as well as completely ignore the knock sensor during timing calculations

 

[viprez586]

I get knock any time my external gate opens(around 10psi) and im only running 14psi on 93 octane. I can't remember if i replaced my fuel filter so I'm going to do that.
I also order a JM fab heat shield since i feel my homemade one may be rattling under load.

I know my turbo housing has 2 very fine cracks in them...wonder if that could cause a problem?

Here's an update on the current situation.

New OEM knock sensor: 2 washers that have formed O-rings on I.D. + Ring terminal crimp to ground. Stock location.
Hand tight - seemingly less PK under light throttle, still WOT 43 count + whenever Ext WG opens, however can get away with 4th gear WOT pull from 3-4k but starts to get ~17 counts of knock

Snugged down(approx 1-1.25 turns past hand tight) - Much worse PK under light load, same conditions under WOT, Ext WG open, 4th gear pull.

New external WG dump tube - dumps next to Radiator + Alternator (Don't worry i wrapped the tube with heat wrap).

I also installed a new harmonic balancer because mine was bad, no real difference.
I did notice however my timing belt is whining at 4k + up, it mimics the sound of an accessory belt being loose. Timing belt + components have 13k on them - defective idler maybe? Also Passenger side of belt has very slight feather edging.

I also noticed sometimes my voltmeter on my SAFCII reads 11-12 volts at idle from time to time, rev it up a couple times and it'll eventually go back to 13.5ish.
I've heard of people re-wiring their alternator to fuse, fuse to battery and it helped with voltage drop issues + i think i thought i saw some mention of re-wiring helps with PK.

It's about 12*F out right now so that has been keeping me from working on my car.
I'm about to run a ground to the sensor, tuck it to the firewall, and run a knock alert system that isn't so #@$@ing picky!! Like in the link below.
KS-3 Knock Detection and Engine Tuning Systems

 

[dsm-onster]

I would try to turn your wastegate outlet away from your frame. . . A piece of pipe or something. It would be worth a shot.

I've heard of a weak alternator encouraging phantom knock, as well.

 

[turboglenn]

There's so many things not even related to the engine's internals that can cause phantom-knock that its not even funny. i found a few on my car this last summer, the AC compressor being one of them (even when it wasn't engaged)... ball joints, bad CV's, loose bolts, loose cross members..check everything.

Also for a good knock sensing unit check out J&S..the 2nd unit down on this page in the link is an older model out of production, but John said if some one requests one on my referral he will build one for you. You can also have it custom tailored to your engine and sensitivity level.. it also can use a variety of 1 and 2 wire knock sensors... Go with the Bosch or Delphi "flat response" units.. don't' get a resonance style one like the GM that comes with the kit for the eclipse.

You can't use his new viper system because our cars are CDI ignition, but if you were to go COP it would work then.

Also, the J&S unit can be set to only pull timing on the cylinders that knock (you can see what ones they are on the oscilloscope because each one has it's own voltage and frequency assigned by the ECU part of it) IT can pull between 10 and 20 degrees and has an optional dash monitor that shows how much is getting pulled and on how many cylinders... I've leered from using the scope and judging the light from the LED's that i can tell what cylinder I'm having trouble with most of the time now...awesome product

 

[Ceddy]

I've been having horrible PK since I installed an alternator relocation kit.
I'm getting 20+ count from just free revving. I car is undriveable.
Thanks for some of the ideas guys posted for getting rid of it.

Does anyone know what size wrench you need to remove the knock sensor?
I'll have to borrow one that big. And searching is giving me conflicting answers.

Thanks.

 

[viprez586]

I've been having horrible PK since I installed an alternator relocation kit.
I'm getting 20+ count from just free revving. I car is undriveable.
Thanks for some of the ideas guys posted for getting rid of it.

Does anyone know what size wrench you need to remove the knock sensor?
I'll have to borrow one that big. And searching is giving me conflicting answers.

Thanks.

15/16" stubby wrench or, you do it like me and cut a slice into a socket much like an O2 socket.

 

[viprez586]

Added some new parts today.

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JMFAB heat shield (I thought mine might of been rattling)
DSMISC.com ISC(probably not associated with PK but i was getting annoyed by morning surge)
OEM fuel filter.

I decide to hop to it and make my own custom dump tube.
This takes some patience. I used one of those metal pipe cutters to get my pieces and used a huge stationary belt sander to correct my angles.
Here is the pipe halfway done.

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And a test fit. There isn't much room to dump your Ext. WG and i felt like dumping it in the direction of the KS would only encourage PK.

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After tacking all my peices together and checking for clearance i wrapped it with exhaust heat wrap. It comes close to the radiator support but it does not touch. Now it is dumping below the crossmember. Please ignore my bent air scoop, I've been plowing snow with it.

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SO...yeah all done. I also moved my Knock sensor to the A/C compressor location. In the picture below you can see exactly what I'm talking about.

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So i decided to go to get some E85 to see if that would help any bit since i haven't tried race gas in a long time.
Upon leaving my neighborhood i encountered the expected High knock sum in 1st + 2nd gear.
Shift into third, ease into the throttle, Ext. Gate opens at 14psi and to my surprise NO knock.
Go WOT with ~1-2 counts of knock till 6.5k, 4th gear no knock.
I was so excited i reached down and turned up the boost to 17psi, tuned to 11:1 AFR and still same thing.
I didn't get time to do too much tuning since its soccer mom Sunday out there, Not to mention Holiday shoppers, 5*F weather with 30mph gusts and blowing snow drifts. It's hard to tune loosing traction in 3rd + 4th gear going solo and trying to watch your timing, Knock count, AFR, IDC, etc. Overall im pretty happy that i at least got it halfway figured out until some warm weather kicks back in.

 

[JayRolla]

So do you think it helped from moving the KS? Is that really a good location to move it too. What happens your just missing the real knock?