I've almost lost my patience with this car, I'm so tempted to sell it right now and get a 240sx, its just this damn part throttle knock, its fracking pissing me off! I've posted here, dsmtuners, dsmtalk and the yahoo phantom knock group and no one has really helped me to I'm begging for help, please!!! So heres it is, I'll try to make it simple and easy to understand.

Problem 1: While accelerating from a stop in 1st, 2nd and 3rd gear I will get knock, enough that the car will hesitated and buck a little. It started off only been periodic where now its almost constant, yet the knock varies, sometimes 43 counts, sometimes 15 counts and sometimes, yet rarely no knock. If I floor it the car while its knocking like this it boggs and the knock stays, but slowly goes down. If I floor it when there is no knock to start it pulls fine. I've noticed that the knock seems to come on from 2600-3300, after 3400rpm it looks like it drops off slowly, its generally that range that it happens.
Here are some TMO logs of what I'm talking about.
http://www.pbase.com/image/20869006
http://www.pbase.com/image/20869065

Problem 2: When crusing in 5th gear or even 4th in the 3000-3500rpm range at steady throttle out of nowhere it will knock 43 counts and hold like that until I let off the throttle or it will just drop off all by itself.
If I let off the throttle and give it throttle again the knock will climb right back up, I have to completely let off for a second or two then give it gas again and it will go away for a bit.
Here are some more logs of what problem 2 is:
http://www.pbase.com/image/20869013
http://www.pbase.com/image/20869063
http://www.pbase.com/image/20869011

What I've done to try and fix all this:
- First I played with my fuel trims, up and down, no change, right now its at 100% for all 3 trims.
- Then I got the new 3g lifters since the old ones were ticking, no change at all.
- Took EGR blockoff plate and put original one back in, still no change.
- Cleaned carbon put of combustion chamber, all clean now...no change.
- New plugs and wires
- New coil pack
- Base timing at 5*
- Knock sensor was replaced 1 month before this started
- Adjusted TH points on AFC from 30 lo 70 hi up and down and now 20 lo 60 hi and initially it helped, but then later that day got in the car and no change, still knocked.

About 3 weeks before this all started I had removed the balance shafts and filled the driver side and front motor mounts with urethane..more vibration in car now. Also replaced crank, oil pump seal, new oil pump gears and found no metal shavings in the oil pan, car still has perfect 160psi compression.
At my last oil change I did notice some fine metal flakes in the drain pan...hope its not worn rod bearings causing knock, but then again I don't hear any rod knock, just the odd injector tick.

So at this point guys I'm out of ideas and almost out of patience, so PLEASE could I get some help here, I'm desparate!!! I want my old knock free car back!!

Thanks in advance

Hello Ryan.

I remember you previous posts.

Just brainstorming;

1) Dono if you already tried but the Knock Sensor might be Over or Undertorque, heard about that one before. Take if off, clean the treads with a tap (chase the treads), reinstall it with some Tefelon Tape.

2) The Knock Sensor might also pick-up some Engine Vibrations induced by removing the B.S.

I would lean toward the Engine Vibs "theory" as the "knock" happends at/or around a constant RPM (frequency). I don't know how you could validate/test that theory.

Look for anything that might be loose on the Engine, maybe a small braket that could cause the KS to "hear" something...

Again these are just a few shots in the dark.

Last note; don't sell the thing, you'll find the problem.

Ghislain.

I did check the knock sensor torque Ghislain, I made sure it was not tight. Tomorrow I will remove the knock sensor and just zip tie it to the side and see what happens. As for cleaning the sensor, its brand new and the threads are clean. I will also try the teflon tape thing, but from what I read the threads are what grounds the sensor to the block, the tape will not allow it to ground.

Dont dump on me for asking, but is your new knock sensor in the right hole (I made this mistake once

Thats not true, use the teflon tape. tighten finger tight + 1/4 turn.

Can you post another log where you are driving the car and show rpm, knock, timing, injector pulse width and airflow hz. Your first log is missing the last 2.

Seems like lots of people have this problem, me included. Please keep us posted.

I made sure I put the knock sensor in the original hole.
I'll try the things you mentioned Len and I'll post back with the results, and another log.

Mods:
18g turbo @ 20psi
2g ex mani and 02 housing
550cc injectors
Fuel pressure set at 44psi
Walbro 190lph pump-rewired
S-AFC
Supra SMIC
full exhaust
all gauges incl EGT
full ic piping
no balance shafts

Here are some more logs Len.
This one is when the engine is still cold, you can see it has only been running for about 3mins.
http://www.pbase.com/image/20898175

The next one is just accelerating from a stop.
http://www.pbase.com/image/20898172

The last one is while crusing at 2750rpm in 4th gear, this is when the engine has reached operating temp after running for 9mins.
http://www.pbase.com/image/20898181

What I'm thinking is that when the engine is cold the oil is still thick, any slack in the engine whether its bearings or whatever the thick oil fills the slack. Once the engine is warmed up and oil thinner it will allow any slack in the engine to make noise, ie: rod knock as an example. Its just a thought, hope its not the problem, just thinking of any possible reason to cause this knock. And I don't hear any odd noises from the engine when I rev it either.

Oh and I put Teflon tape on the knock sensor and as you can see in the logs, no change. As for where the sensor is screwed in picture the back of the engine you have 3 spots to bolt it into, mine is on the top right (pass side) just under the intake mani bracket.


* *<this one here

*


I also checked the TPS, did all the checks and its all good.

I know Wes you don't have your balance shafts anymore, same as me, possibly that could be the cause. I also have filled motor mounts too. Now to get this straight, the balance shafts just cancel out the vibrations that are being produced cause of the 4 banger design, firing 180* apart. So the vibration is there in the engine with the shafts in, its just the shafts that make their own vibration to cancel it out so that in the car we can't feel it. Now with the shafts removed the vibration is still there like is was before, but now without the shafts we just feel it in the car? does that make sense?
If so then the balance shafts have nothing to do with it cause the vibration is gonna be the same regardless.
Also it seems that the knock happens from about 2600-3500rpm, below and after that its all good, I can drive the car on the highway in 4th gear at 3900rpm and its fine and it only happens when there is a certain amount of load on the engine. Drive it hard thru the gears and no knock, accel slowly and no knock or almost none. While crusing if there is a slight-moderate load on the engine and in that rpm range it will knock.

ok i'm babbling...let me know what you think

Wrong hole Like I said, I made that mistake before and I had knock problems just like your having. After I moved it to the correct spot, no more problems.

It should be between cylinders 2&3 at the bottom...

Mine looks just like this http://www.plymouthlaser.com/knock.htm I can see that its in the stock location cause you can see the glouey crap from the old sensor that has dripped onto the block, right below where the sensor is.

I also checked the CAS, ignition coil and transistor and all seem to be working fine, did the checks described in my haynes manual. Checked for boost leaks, none found.

I went through all my datalog sessions from when I got the logger on July 31. This was only 6 days after removing the BS just so you know. If I look at my loggs I can see that I had this part throttle and constant throttle knock problem only it was not as bad as it is now. My guess is that this has been an ongoing problem only I never noticed it until that one night on the 401 on Aug 4th when I saw with my own eyes the EGT temp rise to 860c while crusing, so it doesn't seem like this is new, I just didn't notice it. Again if i look at the logs i can see that it has progressivly gotten worse over the past month, almost to say that something is wearing in the engine and causing some false knock, that might explain the fine metal bits that came out on my last oil change.

just another desperate thought.

I am hoping it's not the motor, I just put it in 12 months ago.

Hey Ryan at this stage is it worth dropping the oil pan to take a better look at the bottom end? I know it is a pain in the ass but I cringe when your story brings back memories of my spun bearing and finding metallic sludge and then shiny bits on my pick up mesh. For $25 bucks you can get the Amsoil oil test analysis kit which will give you a break down of whats in your oil.

oil analysis


I have something similiar but happens at lower rpm esp with a bit of load...2000 rpm with 40+knock 1st/2nd gear. But I think mine could be an intake manifold "fart" that gives a false knock until things heat up and it seals. My diagnostics have yet to confirm this so i think I will be forced to bring it in esp after Darko's post on the fun he had changing his manifold gasket.

Yup, thats were its supposed to be...If you look closer, there's another hole closer to the top of the block. When you said yours was at the top I assumed it was in the wrong hole. You have it in the correct spot.

What kind of metal bits....silver, gold, steel, aluminum..either way, doesnt sound good.

Try checking for error codes. I assume you disconnected the battery when you replaced the knock sensor. You might still be running a faulty code(s).

The metal was silver, I think I'll drain the oil out later today and see what comes out...maybe I'll put in some 15w50 oil...thicker right??? if the knock goes away then mechanical knock is likely.
The only error code I have is the speed sensor, thats been there for awhile.

If the metal bits where big enough to notice then you should check that out as well. Shot in the dark but if your piston is slapping from something being damaged or worn that could be the knock its picking up. I didnt have a logger when mine went and the audible tapping took a few months and a couple of mechanics visits before it finally went. So if you catch it before it goes terminal you might be able to save some damage=cash.

Well I just changed the oil. This oil was only 2000km old and I had already lost about 3/4litre so far, anyways there was no noticeble metal bits, but when I looked at the oil it had a goldish/brown color to it, and when I poured the oil into a container with the sunlight on it I could see a whole bunch of tiny metal in the oil. Its hard to describe but to me it looked just like metallic paint, ya know how metallic paint has small bits of metal in it, very small that is and they kind of sparkle in the light, well my oil sparkled in the light. What do you guys think?
The thing is the engine sounds very quiet while idling and driving, no knocking or anything. I know what piston slap sounds like, plus I still show near perfect compression???

You have checked everything on the ECU/Electrical side. Hate to say but Metal Flakes don't lie...

As for the Vibs; Like you said, they are present even if the BS are in (just not felt by the butt o-meter).

Having said that; I still think the problem is Engine Vibration related, as per some of the Logs (just baffled with the cruise speed knock...). Something is probably loose or worn causing the unwanted noise.

Having one of these fancy OIl Analysis would point out to the Wearing component, if that is the case anyway...

These test (Setaflash) are done frequently in the Helicopter world (Military Chopper anyway) and it's amazing how it can pinpoint to a failling component.

Ghislain.

Well I did some more logging today and looking at them I'm getting knock right at 2500-3500rpm nothing before or after and its full out instant 43 counts of knock, or it climbs up quickly and its dependant of engine load. Also I can feel in the steering wheel and gas pedal the vibration from the engine, it starts and ends at that exact RPM range. Also while logging 02 trim and knock I can see my 02 trim is perfectly fine, right at about 90-110% so basically I've ruled out any idea of it being tuning knock...also plugs look normal. All this and the fact that I'm seen fine metal particles in the oil leads me to believe that the engine wear is causing some engine noise that I can't hear, but my KS can. So if all goes well I'll pull the engine out this winter and rebuild it and hope for the best.

Your first couple logs look familiar...
Here is one of mine:

http://img.villagephotos.com/p/2003-9/218243/PartThrottleKnock.JPG

I don't see it all the time though. It's every once in a while and I think usually in 4th gear @ 25% throttle between 2400 and 3000 rpm.

I have some similarities to you I think:

.freshly rebuilt motor (3000km)
.no balance shafts
.3G lifters
.prothane motor mount inserts
.EGR block-off
.new plugs & wires
.base timing 5deg.

Using a wideband O2 I've seen the mixture is fine throughout that RPM range, however this was only looked at in 3rd gear. I'm pretty certain I'm not leaning out where that knock is.

I'm not sure about the condition of my knock sensor, or the torqure for that matter.

I think it's just vibrations, but how to make it go away??? I'd like to solve it too.

Ummm, and on a fresh rebuilt motor too. I'd keep an eye on it see if it gets worse. If its just a periodic thing that you don't notice unless you have the logger running then I'm sure its nothing to worry about. Rob when you had your engine rebuilt did you get it fully balanced?

Yes it was balanced.

I'm going to be doing a fair bit of logging tonight and we'll see how frequent it actually is, and maybe there is a pattern I can pick up on. That snippet was from a 25 minute log of me driving all over the place, and I only saw that knock a few times. This was the worst case of it I've seen - mostly it stays below knock sum 20.

Also see if you can log 02 trim, RPM and knock.
And when you accelerate do you get this knock...1st, 2nd and 3rd gear.

Edit: by looking at your log again it looks like you were on a decline in the road. IPW and throttle are going down slightly and RPM's slighty going up. I only got knock when there was a load on the engine.

Ok here's one with some load on the engine. I put in O2 trim now too.

It knocks under the same conditions, and this time I can say for sure it is in 1st gear.

http://img.villagephotos.com/p/2003-9/218243/PartThrottleKnock2.JPG

Well thats hard to say what it is. Its only in 1st gear there and a lot of guys get 1st gear knock. Is that the only time it happened when you were logging?
You may want to adjust your TH points...thats if you have an AFC. Mike Jackson has a good write up in the Fuel Tuning section on 1g AFC Tuning, yoiu might want to try that.
Just something that I've learned is that part throttle knock or phantom knock happens for many different reasons, lifter tick, worn engine, bad KS, tuning issues, etc etc.

So noone has balance shafts who has this problem? Can we find anyone with balance shafts who has this problem? Your logs look the same as mine.

I am going to hook up an ear phone and an amplifier to my knock sensor to have a listen to what this sounds like, and then MAKE it knock to see what it sounds like. I have heard that the big Subaru tuners do it by ear since there isn't any DSP taking place in the ECU's.

I had the BS in and same issue.

I got the rear one taken out now, but car is not running yet, hopefully it doesn't get worse.

My case, I'm fairly certain it's the lifters.

Hey I have an SAFR so no TH points to adjust...

Now that I take a closer look at my logs, I can see that there is frequently a knock sum of 5 or so in 1st, 2500-3500rpm. Sometimes this could knock up to 20 or higher but it is rare - only a couple times out of a half hour drive.

I also see that I am getting knock while cruising in 4th, just like you Ryan! It just doesn't happen often - in a half hour drive I only see it once.

I can go WOT in 4th all the way to redline with 0 knock. Or, I can cruise around in 4th at 2500rpm and get 40 knock. Or sometimes I get knock at WOT too It doesn't make much sense, especially since the SAFR doesn't care that I'm WOT (apparently).

Now Rob you have a freshly rebuilt engine, balanced, and new 3g lifters and still have some knock which is weird. You may want to do a log with just 02 trim, knock, RPM and throttle, that my shed some light as to whether your case might be tuning related.

Also Wes is your engine original or rebuilt? do you have the 3g lifters?

My logs sound the same as Rob's, however with my TMO ECU and the timing guage staring me in the face ALL THE TIME I see it happen more than most. I can drive to my gf's place and it may happen once (30kms across 401) or go there and see it 3 dozen times.

I have a JDM big 16g motor with the lifters that came in it, and HKS 264 regrinds.

For me I can drive on the 401 for 20mins and have it happen constantly...43 counts will hold, EGT hits 880 cause of the pulled timing and I have to constantly let off the gas to let the EGT fall down, but then the knock comes right back. It will do this over and over for maybe 5mins or so, then stop for a bit, then come back again. Sometimes like the other day it only happened 6 times, but city driving its brutal, constant bucking from full out knock in 1st to 3rd gear.
Wes there is a possiblity that its your lifters, you should also check your oil at your next change, shine some light on it and look for metal particles, also maybe rip open the filter and look for metal, thats what I'm doing.

I've had this problem for a long time, and I have never seen anything odd with the oil and I take a good look at it every time, I have also seen no abnormal oil usage.

Man, I want this gone.

I have them in my log... What difference does it make if thoes are the ONLY items logged?

I just had a thought... at 25% throttle doesn't the ECU switch to open loop? Maybe we are all fine in closed loop, but as soon as we go open loop it leans out and knocks? Too much boost at part throttle for the fuel maps in the ECU?

Read #4 on this link.
http://members.rogers.com/mrjackson9/FAQs/SAFC_Tuning.htm
It will explain this, I know you don't have an AFC Rob but you might be able to see if maybe your running too lean or too rich.
As for closed loop, open loop I'm not sure when it changed over.

Open Loop, Closed Loop Change over thanks to Mr. Costall

Seems the changeover point is right around 4k rpms or big changes in TPS. I've also heard high TPS value, but I'm sure it's higher than 25%.

Should be easy to tell if you have a logger, the o2 reading should stop bouncing up and down and stay fixed.

Okay guys I think I found something rather interesting that you will want to read.
http://autos.groups.yahoo.com/group/phantomknock/message/1555

I know its a long read, but read it and all the replies. It basically talks about interference in the old and tired wiring messing up the knock sensor signal. I emailed the guy and asked a few more questions, this does look rather promising.
Let me know what you think.

I am going to read the article from Mr Costall in a moment, however that's interesting. I don't have this problem above 4k.

I doubt its a closed loop open loop problem,but read the link I posted, its for a possible fix for this knock problem.