Thread: False Knock?

So I have your standard 3.4 setup - Headers, 1.9 rockers, 180* stat, 104 plugs, cold air intake, and an Overkill PCM. The car runs great and pulls pretty hard throughout the RPM range. I've noticed lately that I am getting spikes of KR at random rpms/speeds. It will stay at 0, and remain at 0 when I ease into the throttle creating more boost. However, when I stab the throttle or go WOT, I will get random blips/spikes of KR upwards to 6*, then it will fluctuate back down to 0 (or less than 1*). I know that my front sway bar is shot, as I car hear clunking in the steering and sometimes a vibration from the engine when I shift gears.. My stock motor & trans mount also need to be replaced. So could this be false knock? Should I be concerned? Next week I am install a GMPP handling kit and new solid rubber mounts. Hopefully then the knock will go away then?

Might be false knock.

But you are also seeing the KR when you stab the throttle. Could very well be real knock.

Take the blower belt off and see if you still get the knock or not.

replace that parts that are banging around and figure it out. burst knock is not uncommon for a 3.4 setup with a crappy tune.

Flash KR. Tune related. It took me quite a while of tuning to eliminate mine(had a zzp1.0 file and I got 4ish degrees of KR when hitting boost)

Chris.. once my trans is in.. I'm starting to tune. Should be within a couple weeks. I'd say its in the tune.

FWIW, never assume any KR is false. That way you will keep your foot out of a potential piston killing situation. If you see KR, back off.

Originally Posted by BillBoost37

Chris.. once my trans is in.. I'm starting to tune. Should be within a couple weeks. I'd say its in the tune.

FWIW, never assume any KR is false. That way you will keep your foot out of a potential piston killing situation. If you see KR, back off.

I think I have a bad 02 sensor which could be contributing to the knock. At WOT I can feel it skip a few beats throughout the rpm range as if I am getting a misfire. According to my scan gauge there are no misfires, and my 02 seems pretty low at times. Or it could be my junk ZZP wires

I'll put money on it being the wires. Max didnt' make a month on his before they were tossing misfires and other crap. I have a fresh set of AC Delco wires that should be in by Wed. Sell'm to ya!

Originally Posted by BillBoost37

I'll put money on it being the wires. Max didnt' make a month on his before they were tossing misfires and other crap. I have a fresh set of AC Delco wires that should be in by Wed. Sell'm to ya!

I've been running these wires for over 2 yrs now with no issues, so I don't understand why they would all the sudden be giving me problems.. But yeah if you want to sell those AC Delco wires then I will probably take em.. So are we still on for Wednesday? Felt I should mention that I also have new strut/coil assemblies for the front that I figure we can just bolt in while were in there.. Forgot to tell you on the phone the other day.

2 years is a long time for wires.

Originally Posted by Bio248

2 years is a long time for wires.

I've had wires on other vehicles last 50k+ miles