Ok,

To started off I have researched every post here and the other board that deal with the KR prolbems. What I have done so far:

Both Knock sensors replace since its a 98
Made sure the K sensor harness was A OK
Exhaust free of banging
No aftermarket pulley
Better gas.

So I see about 4 to 4.4 spike and then it comes down, around 3800-4000 rpms, here is were it gets weird. Not all the time, not in all gears, but sometimes in all gears and at different RPMs. I've fought the problem for about six months. Getting ready to ditch the y-pipe and catback and maybe even the chasis mount torque arm, to test. Do any of you think this will help? If not what will?

MODS:

Engine:
Stage 2 Heads
CC 212 218 523 529 @ 114 Cam
MAC Headers ORP
No ERG removed w\ HP Tuners
No air tubes w\ HP Tuners
Cartek Clutch

Suspension:
HP Motorsports Torque Arm
Lower Springs
LCA and Adj Panhard rod.

 

I had it after I removed the EGR and disabled it with HP Tuners. It went away after I zeroed out the EGR timing advance table. Some say do it, some say leave it alone.

 

If you are getting detonation, try colder plugs, too. I am going to have to try colder plugs myself soon to try to chase away a little knock around 5500. It's real quick but it's keeping my timing at WOT waaaay down. Other than the RPM, is this what you're experiencing?

 

Running TR6 plugs because I use to run nitrous.
Tom

 

Here is my lastest Histogram of knock and timing.

 

Been there, done that, bought the t-shirt. My histograms always looked just like yours. I have a new tune in that looks a little better, but it was raining yesterday...so I couldn't lay into it. Sideways in the rain doesn't always make the cops happy. Even though it is fun...

 

4400 RPM is where I seemed to have the last
wisp of KR, I had to pull a degree of spark out.
One thing you could try, is to reduce the attack
rate and increase the decay rate on the "Fast
Knock" tables. I think mine are .200 and .200
across the board right now, and I see 1/10
degree per time-tick recovery and my KR "jump-up"
is only about 1 degree. What this does is from any
funky mechanical resonance that might trigger the
sensors, make it not "fly off the handle"; persistent
knock will still run it up but a single anomalous
event will not jack it to 4 degrees in an instant.

Valvetrain clatter is one thing I didn't see mentioned.
If you can hear valvetrain noise above the motor
then that would be bad. Ever had the covers off to
check for rocker play, or the infamous "my roller
bearings moved south to the oil pan" problem?

 

It's got CC lifters and pushrods. I've checked the rockers about 5000 mile and everything seemed A OK...

Also for the knock decay rate.... I don't think the 98's have it. Am I wrong? Where is it?

 

Best thing I did to get rid of KR was to go to a bigger radiator (SLP hi cap) and a 160 T/S.

 

I got the 160 stat. It seems to be helping...so far.

 

Ok, I thought I'd list all that I have done this weekend:
Two Treatments of GM top engine cleaner
Changed Plugs (NGK TR6 regapped to 40)
Changed oil because of cleaner
Re-tuned LTFT's (because of new re-gapped plugs)
Ran tank empty got 5 gallons of 100 octane
Drove 20 miles reset the PCM and re-logged

Guess what, still have KR and it looks exactly the same as before. I'm at a loss. Maybe I'll try a 160 T Stat.

 

It sounds more and more like false knock, BlackWS6. FWIW, my histograms look very similar, but I get my KR from 800rpm up. All in the lower left-hand facing cells.

I always get hits of 8, 9, or 9.1 degrees. It's very consistant.

JimmyB, I really like your suggestion about attack. I've got my decays set to recover pretty quick, but I never really considered turning down the attack rate. I get almost near verticle spikes.

 

Well latest update, I've also tried a new tranny mount and I also replace a bad u-joint in the driveshaft... Guess what its still there. I still can believe it can be a timing issue if it only does this in third and fouth gears. I'm gonna try a few weird things this weekend. I'll let you know.

Tom

 

As another option, you could try a new cam position sensor and/or crank position sensor. I have seen them go bad and cause serious KR.

 

I am having the same problem with my 1998 camaro I just got that has almost the same mods S2 heads/tr224 cam/macs/ no egr/air removed with ls1edit/160 tstat/ngk tr55/asp pulley but mines a A4. It gets a lot of detonation at half throttle when just trying to drive in traffic. Hope you find out what it is, might be the same problem I am having?

 

can any of the tuning programs turn off the knock sensor?
kock retard i dont see being a problem until you are wanting to do some wot running

i was thinking it would be nice to disable it only for racing, and as long as you are sure that the motor is running right

 

You can prevent it from pulling timing with HPTuners. I would not recommend it though. The closest I have come is at the RPMs I believe I am having false knock I set the max knock retard to .5 in the KR by RPM in PE mode table. And that is just until I get something to desensitize my knock sensors.

 

reason i ask is because if you are pretty sure its false knock and yo are not running nos then i would do it when i get to the track or before i go to the track and then change it back for everyday driving

 

Hey. That is a good idea...LOL.

Unfortunately the street is where I want the power the most.

 

have you got stock or aftermarket plug wires?