Knock only on rolling WOT?

[Spl170s]

Trying to figure out my possibilities on this issue.

From a dig.....just straight launching andf WOT whole time.......0 to .7 for a split second and going away.......good run. (scanmaster 2.1)

From a roll(30mph+) WOT run....i get knock like crazy. Saw upwards of 14 at one time and just floating around over 10 from there till i let out......

Why only on rolling WOT punch does it do this????

 

[gaminoree]

????

Mine does that too. Heard it could be the knock sensor,torque convertor,or a bad ground. I am still wondering myself, anyone out there have ideas????

 

[87GNSteve]

Mine too.....(on the GTA)
and I thought it was because I did something wrong in the swap but just like the first post it is fine from a standing launch.
My suspicion was the crap oxygenated gas.
Possiblity of the converter because from standing mine is in 2nd or D.

 

[Spl170s]

I would also be in 2nd or 3rd upon the WOT punch when i get the knock really bad. I even get it with just 2-3 lbs of boost when i start to roll on! Its just crazy.

But, then i can turn around and go from a dig....15lbs whole time and get basically no knock!

I have been thinking about rechecking my torque converter bolts as well. Could be a possibility for me since we recently swapped them.

I jsut rechecked my knock sensor recently because i thought it was suspect......it wasn't fully tightened before....now it is at 14ftlbs. I also have the torque strap on the car.....

Only other thing i am starting to wonder on mine is whether i am putting to much fuel into the car at WOT. I have a maf trans and i have it set on 2% rich on WOT. I need to watch my O2 readings better next time to see if they are going to high on the WOT punch. TO rich can cause knock to from what i have been reading?

 

[salvageV6]

It could also be your engine is already under more load and not getting into PE enrichment mode fast enough.

Downshift and tranny KR is also possible as well as wheelspin KR etc.

Depends on how you launch standing still to what happens from a roll for stuff hitting etc. possibly causing it.

If you have alky. during the roll start spraying manually quicker just before you punch it and see if the KR disappears, then you know it's octane/fuel related.

Direct Scan on during the two types of runs would help find the problem most likely.

 

[Spl170s]

Well, my list goes like this.

1. Check Torque converter bolts / tranny bolts.
2. Drive check knock
3. Change Maf trans setting to 0% rich on WOT and make sure i am not over fueling the system.
4. If this doesn't work, bang head on wall.

Knock is such a frustrating thing......very very annoying.

IAc's are right on, TPS is right on. BL perfect......everything looks as it should...and getting knock....

 

[Jerryl]

It could also be your engine is already under more load and not getting into PE enrichment mode fast enough.

I concur with this.
Like the old days when the accelerator and/or needle was set incorrectly?
Could this be a fuel map vs LV issue?

Dumb un-scientific questions;
Do you know what the O2 readings are at part throttle?
Does it knock if stomping the throttle so the TPS reads less than 4.0 volts? (with like a piece of foam under the throttle)

 

[86BGN]

Mine shows knock from a roll unless I start spraying alky before I floor it.

From a dead stop no problem or if I ease into the throttle no problem, I can even do a boosted launch and everything is fine. I wish there was some way of stopping it from knocking at a roll but I haven’t found one or thought of one either.

 

[Spl170s]

i will watch my O2's next time i drive it.

Today i set my WOT back to "0" on my translator setup.

When i was going from a dig and stomped it...no knock....and o2's were in the 790 or so range and slowly decreasing down to the 760 range before i let off...this was with the car going beyond the speed my dash would show anymore.

When i rolled and stomped...my O2's were similar if not a little more rich and i knocked like crazy....even part throttle i get knock when i roll on it......

 

[DragulaGN]

Mine usually pulls like .7 or .9 but I have seen it pull as much as 41.x to 53.x with no audible ping or knock. Also seems to do this when the air temp is above 85 degrees. Last time it was 53.2 and this was on race gas 113. Like I said its not all the time and especially if the air/humidity is high. Im am super stumped. I dont think its fuel related and like I said there is no audible ping or knock By the way, turbo has about 1200 miles on it and the motor probably has about 3200 now.

 

[Spl170s]

Likewise, i don't hear any audible knock either. of course, my roller valvetrain is a little noisy though...

i am going to also try swapping chips too. i am currently running a turbotweak chip setup for me. i have the old chip that came with the car though i could try. Just to see if there is a difference anyway.

 

[DragulaGN]

Same here. I have the T&D rockers and they seem really noisey. I am also using the TT chips. Let me know what you find out

 

[Spl170s]

update, after blowing a HG recently, i tore into the motor for replacement....and i found something very disturbing. my heads had debris in them from the valve springs.

looks like everything is pointing to a improper set of springs being used on the car and that lead my car to break 7 out of 12 inner (damper) springs. this also lead to torn up valve seals. these were nice heads too. looks like engine builder shop didn't specify the right valve springs to be used when building motor..and this lead to broken springs.

now, after replacing all of the springs and doing new HGs....i have NO roll knock at all. none whatso ever.

This is my story anyway............