Valvetrain ticking and phantom knock
I have this same problem I believe.. I'm getting phantom knock at a stand still revving the motor.. ill get up to 36 counts of knock!
In my attempts to stop the ticking, I have installed TTP non ticking lifters, replaced all exhaust gaskets, went back to stock injectors & stock cams (from cosworth272), boost leak tests, compression tests (solid 150psi...), new walbro fp, inspected valve train numerous times, tried all sorts of different weight oils..
Sadly, I have not found the source of the problem, nor the cure.. I have shut off my knock sensor.. I tune my own car via ecuflash & zeitronix wideband... I'm safe cuz I'm always monitoring the motor..
In my attempts to stop the ticking, I have installed TTP non ticking lifters, replaced all exhaust gaskets, went back to stock injectors & stock cams (from cosworth272), boost leak tests, compression tests (solid 150psi...), new walbro fp, inspected valve train numerous times, tried all sorts of different weight oils..
Sadly, I have not found the source of the problem, nor the cure.. I have shut off my knock sensor.. I tune my own car via ecuflash & zeitronix wideband... I'm safe cuz I'm always monitoring the motor..
I had my doubts, but you were right. Every time it started to rattle, I pinched the line with a needlenose and it stopped. As soon as I'd let go, it rattles again. Does this cause your car get really high knock counts like that? Or does that mean I need to replace mine? I really hope this is what's causing the knock problem, and not something else.
Last edited by miller121mx; Sep 12, 2010 at 06:32 AM.
I havent gotten to replacing mine yet either so I couldnt tell you if it'd cure the knock, although, it'd make sense that it would if its knocking audibly enough for the knock sensor to pick up
I get random knock like you were discribing too, so it very well could be it.
I get random knock like you were discribing too, so it very well could be it.
I replaced the PCV valve, and the rattling noise stopped. The knock is still there, however. I need to do some more logging, but quick revving in neutral produces lots of knock (over 25 counts) around 3600-4000rpm. For the sake of having more info I will add this: At this same exact range of rpm, my exhaust sound becomes very raspy. Think stock Civic with an Autozone fart can. I don't know how it could be related, but thought I'd throw that out there.
I'm going to do a couple light throttle pulls and log them. We'll see what happens.
I'm going to do a couple light throttle pulls and log them. We'll see what happens.
Do you have a clutch or Throw Out Bearing rattle at all? I know I got a couple more Knock Counts when I installed my twin disk, for me, free revving in neutral I only get about 9 counts at the same RPM you said, and about 80 load. What do your timing tables look like in that area?
In that rpm range and 80 load, my high octane timing table is 24*. I just hit 19 counts of knock in about the same spot. I did just install a CM stage 3 clutch. Just the single kevlar disk. No audible rattle from it that I can tell.
I just did a light throttle pull in 3rd gear, about 50-60%. Only 1 to 2 counts of knock from 2700 rpm to 3600 rpm, nowhere else in the rpm. Doing pulls on the street I don't hit those high knock counts like in neutral. I'm thinking phantom knock would produce a much higher knock count than that. I'll try to talk to Chad tomorrow and see if he still thinks it's phantom knock or not.
I just did a light throttle pull in 3rd gear, about 50-60%. Only 1 to 2 counts of knock from 2700 rpm to 3600 rpm, nowhere else in the rpm. Doing pulls on the street I don't hit those high knock counts like in neutral. I'm thinking phantom knock would produce a much higher knock count than that. I'll try to talk to Chad tomorrow and see if he still thinks it's phantom knock or not.
you can measure the knock sensor with AC voltage on a multimeter. tap it with your fingernail or a screw driver and the voltage will go up. obviously it's not a very scientific method, but can give you a rough indication.
i did this with a 4g64 and 4g63 knock sensor, and the 4g63 knock sensor produced much less voltage with the same force being applied
i did this with a 4g64 and 4g63 knock sensor, and the 4g63 knock sensor produced much less voltage with the same force being applied
you can measure the knock sensor with AC voltage on a multimeter. tap it with your fingernail or a screw driver and the voltage will go up. obviously it's not a very scientific method, but can give you a rough indication.
i did this with a 4g64 and 4g63 knock sensor, and the 4g63 knock sensor produced much less voltage with the same force being applied
i did this with a 4g64 and 4g63 knock sensor, and the 4g63 knock sensor produced much less voltage with the same force being applied
I'm almost positive it's not real knock now. I had a buddy watch evoscan as I drove around. Doing full throttle pulls I rarely get any knock now, whereas the other day I was getting inconsistent knock counts. Occasionally I hit 36 out of nowhere. I thought maybe the knock sensor was just going crazy or something (wishful thinking). While driving around normal, hitting a little boost before shifts, I am getting kind of consistent knock counts (between 1-4) at the same rpm that the exhaust note gets raspy. At this same time, I can hear vibrations coming from somewhere. I will check my exhaust tomorrow to make sure it's not touching anything. I don't know if that might set off the knock sensor.
I am considering draining my tank until there's only like 5 gallons in it, then putting in a 5 gallon can of 110 octane. If it still knocks on the same conservative tune, then I would imagine it's real.
Even if nobody responds, I will keep updating my findings in case someone in the future has this problem and comes across my thread.
Last edited by miller121mx; Sep 13, 2010 at 06:20 PM.
I never found any culprits other than the Kelford cams. Later on I found a bunch more people with the same problem with the same cams. I ended up getting a 5 gallon can of race gas, putting it in my empty tank, and then tuning the knock sensor. It was already on a very conservative tune, plus the race gas, so I just turned down the sensor in small increments until the knock disappeared. Then I did more logging with pump gas to make sure it didn't come back. No related problems since.
I never found any culprits other than the Kelford cams. Later on I found a bunch more people with the same problem with the same cams. I ended up getting a 5 gallon can of race gas, putting it in my empty tank, and then tuning the knock sensor. It was already on a very conservative tune, plus the race gas, so I just turned down the sensor in small increments until the knock disappeared. Then I did more logging with pump gas to make sure it didn't come back. No related problems since.
How do you tuned your knock sensor???
In the load knock tables???