Knock Problem

[BRAD_PADGETT]

I am getting knock as soon as the car goes into boost. In addition to my signature mods I have HRPARTS motor mounts, hot wired ignition, wideband o2 sensor and new closed loop chip and a powerlogger. Here are my powerlogger readings when knock starts. Any ideas? Thanks Brad

Boost .8
KNOCK 1.2 DEG
INT 62.6
TPS 1.7 V
BATTERY VOLTAGE 13.5 V
SPEEED 19 MPH
O2 SENSOR(STOCK) .815
SPARK AD 22.2
RPM 2362
MAF 82.9
LV8 190
TEMP 169
INJ PULSE WIDTH 12.62
INJ DUTY 24.9
AFR 10.30
MAP 106.5
WASTE GATE SOLINOID % 63.5

I get knock consistently on my Caspers knock gauge as well as my updated Scanmaster 2.

.

 

[Boost231]

I am getting knock as soon as the car goes into boost. In addition to my signature mods I have HRPARTS motor mounts, hot wired ignition, wideband o2 sensor and new closed loop chip and a powerlogger. Here are my powerlogger readings when knock starts. Any ideas? Thanks Brad

Boost .8
KNOCK 1.2 DEG
INT 62.6
TPS 1.7 V
BATTERY VOLTAGE 13.5 V
SPEEED 19 MPH
O2 SENSOR(STOCK) .815
SPARK AD 22.2
RPM 2362
MAF 82.9
LV8 190
TEMP 169
INJ PULSE WIDTH 12.62
INJ DUTY 24.9
AFR 10.30
MAP 106.5
WASTE GATE SOLINOID % 63.5

I get knock consistently on my Caspers knock gauge as well as my updated Scanmaster 2.

.

blown turbo. alot of oil is getting pushed out of the turbo into the intake. i just had the same problem. some times it would det. around 1-2 psi somethimes 2-4 if i rolled real slow into it. pull a plug and take a look at the piston im sure its oiley as all hell.

 

[BRAD_PADGETT]

Jerryl has ruled out coil pack issues. My oil consumption is unknown but it is not bad. After 2300 miles I show 3/8 inch above min. My car does not smoke at all. I will pull 2 plugs tomorrow and post PICS. Thanks- Brad

 

[Boost231]

Jerryl has ruled out coil pack issues. My oil consumption is unknown but it is not bad. After 2300 miles I show 3/8 inch above min. My car does not smoke at all. I will pull 2 plugs tomorrow and post PICS. Thanks- Brad

my car didnt smoke at all either but let me tell you there was oil in that intake like a SOB. my plugs looked good but the pistons had oil on top of them.

 

[Jerryl]

Brad,
As mentioned last night ……….
When I had a similar problem (KR at 0-1 PSI) it was a blown turbo seal and a blown HG on my second occasion.
My turbo had less than 18 miles on it and was a rebuild from Limit.
Anything can happen I guess and the plugs will tell you what is going on here.
Man, I hate giving out "bad news" but not sure how else to do this.

In summary;
Boost231 is more than likely correct.
What you are experiencing is most likely the result of oil making it into the chambers.
It does not take much oil, and you may not see any smoke.
The sources of oil can be:

-Leaking turbo seal
Look through the TB and see if it is dry (Should be)
Also, verify the PCV and see if the hose from the PCV to the TB is "wet" on the inside.

-Blown HG
-Worn valve guides
-Broken ring
-Leaking intake gasket
Easiest way to verify these is through a "Leakdown" test.

It is strange that this started when you changed the ignition module and coilpack but that is at least "ruled out" for now.
I will review the log later tonight.

 

[alec296]

i had a similar problem when my turbo went out but i have something like it again but i think the its a vacuum leak at the turbo to intake adapter oring
you can actually see it slightly cocked.

 

[BRAD_PADGETT]

Update- I pulled 4 out of 6 spark plugs and they so far are dry and the same color.(brown) I need to take off my downpipe in order to get to the last 2 plugs. My car has been running rich the past year and a half because of my old TT chip. If the two remaining plugs are dry should eliminate the head gasket issue and leave the blown turbo issue. I hope the turbo is the issue because I can put my spare turbo on and deal with the TA33C over the winter. I will post up once I get the last two plugs out. Thanks- Brad

 

[Boost231]

BRAD like i said on the phone pulling the plugs and looking at them wont tell you if the turbo is blown or not. i pulled all 6 plugs on mine and they looked perfect. you need to either take a pin light and look at the piston or pull the turbo and look into the intake. i can show you what my plugs look like if you dont believe me. my car never smoked and you would never be able to tell by just looking at the plugs.

 

[Jerryl]

BRAD like i said on the phone pulling the plugs and looking at them wont tell you if the turbo is blown or not.

Correct!
Looking at plugs will however tell you if "just one hole" cylinder is the culprit.
Pulling and looking at plugs, the easy things first, never hurts.
If the plugs are all the same, move on to the next test.
If one is off, narrow it down to the lext level of analysis.

Personally, I would not start replacing any "supecting turbo" untill I looked at the plugs, performed a compression test, verified valve action, etc etc.
But, that is just me ..............

 

[BRAD_PADGETT]

Here are thoughts on the situation. I am not experiencing oil loss, coolant loss, no smoke, spark plugs are clean. I deduce that the head gasket is fine and the turbo is not leaking oil. The knock is the same to matter how much the spark advance is changed.

I did notice when I inspected the turbo through the throttle body the compressor blades had a few pieces missing. The knock starts immediately upon boost.

I think the turbo copressor blades are hitting the compressor housing therby creating false knock. The knock goes right up as the compressor speeds up.

The only to check this is to put my good stock turbo on. What do you think? Thanks- Brad

 

[Jerryl]

Here are thoughts on the situation. I am not experiencing oil loss, coolant loss, no smoke, spark plugs are clean. I deduce that the head gasket is fine and the turbo is not leaking oil. The knock is the same to matter how much the spark advance is changed.

I did notice when I inspected the turbo through the throttle body the compressor blades had a few pieces missing. The knock starts immediately upon boost.

I think the turbo copressor blades are hitting the compressor housing therby creating false knock. The knock goes right up as the compressor speeds up.

The only to check this is to put my good stock turbo on. What do you think? Thanks- Brad

Me thinks ..........
The turbo spins even when there is no boost, so, if that was the case, KR would occur under "no boost" situations as well.

The compressor blades are in fact of "unequal length.
Does the compressor whell in your turbo look like this?
Turbocharger Guide

PS:
Log looked fine, nothing unusual.

 

[Boost231]

it very well could be the turbo. its not to out of balance till you start putting pressure to it. i would pull the turbo and put another on it. simple 2 hour swap.

 

[BRAD_PADGETT]

Brent and Jerryl the both of you have excellent advice. I just discovered a major contributing issue to a part of my false knock issue.

The hood adjustment leveler which has a rubber top and meets the hood on metal at the firewall dead center has dried out over the years. This adj levelor now bangs on the hood and creates false knock. I have reduced knock alot by putting grease on it. I also have lowered it as well. I need to get some powerlogger runs and verify. I suspect that I will have to reduce some timing as well in third at WOT. I will keep you posted. Goal- No knock at all. Keep you posted. Thanks- Brad

 

[Boost231]

Brent and Jerryl the both of you have excellent advice. I just discovered a major contributing issue to a part of my false knock issue.

The hood adjustment leveler which has a rubber top and meets the hood on metal at the firewall dead center has dried out over the years. This adj levelor now bangs on the hood and creates false knock. I have reduced knock alot by putting grease on it. I also have lowered it as well. I need to get some powerlogger runs and verify. I suspect that I will have to reduce some timing as well in third at WOT. I will keep you posted. Goal- No knock at all. Keep you posted. Thanks- Brad

wow are you kidding me. that will be a first. i have never heard of that.

 

[timevacuum]

Brad,

Maybe the Alchy needs to be cranked-up a bit. On my car when IAT is over 80 degrees F, I can get by with the knob set on 4-5, but when the IAT is around 45-50 degrees, (like today), I have to set the Alchy at about 6. I get a K.R. I don't adjust the Alchy up when the temps drop.

Its just a thought, and may not be your problem but it sure wouldn't hurt to try it.

HTH,

Bill

 

[BRAD_PADGETT]

I am srewed. I ran a powerlog this morning and kock starts at one lb boostand goes right up as boost inceases. Knock should not start until after 8 lbs boost. Maybe there is something mechanicaly wrong with the turbo or waste gate actuator which is setting off the knock gauge. I will get some cab cleaner as well in order to check for a vacuum leak on the turbo adapter. Thanks- Brad

 

[Eric Stage I]

Hey Brad,
Email me a log if you get a chance.

Eric

 

[BRAD_PADGETT]

Logs have been sent. My next step is to get a cam sensor tool and check cam senor. I will keep you posted. Thanks- Brad

 

[BEATAV8]

Brad,

Last time I had a knock sensor lighting off at 0 psi boost it turned out to be a bottom end problem. You might want to pull the oil filter and cut it open to look for sparklies.

 

[tb3]

What about the knock sensor itself? Anyone know their characteristics when they go bad? do you have another you could swap it out with? I know that their sensitive to torque for proper operation also.