Why am I getting Knock?!

[kTrainHurricane]

so i took the advice given and got on it again tonight...but did the "roll into it from 3rd gear" as i was instructed. Numbers were as follows:
o2-->777.....099
KR-->4.9.....094
I DID see the knock record at either 1.3 or 3.1 before the 4.9, but only those two numbers appeared (dont remember which one it was...dyslexia haha) =/

 

[Razor]

Those numbers are ok. You need to lower boost and see if the KR goes away.

777 is a little on the low side. Maybe needs a tad more fuel pressure.

4.9 is way different from 19

And the numbers where climbing .. next time you see knock numbers,, and they start climbing.. 1, 3, 5, etc.. get off the throttle.

Knock that climbs is real. Means you need to lower boost or get better octane.

 

[jdpolzin]

Make sure you have an adaquete fuel system.

 

[kTrainHurricane]

as far as lowering boost - i have a manual boost controller under the dash (a black knob you turn left/right to lower/raise lbs), but dont remember if the owner said make sure the engine is off or on. Does it make a difference?

 

[kTrainHurricane]

Listened to the instructions given to me and lowered the boost today. I slowly rolled into it from around a 20 in 1st gear, and boost locked in right at 15lbs (from 16-17 before). Had no knock until about halfway throught 2nd gear, which reported as follows:
o2-->839.....041
KR-->5.4*.....041

 

[Razor]

Listened to the instructions given to me and lowered the boost today. I slowly rolled into it from around a 20 in 1st gear, and boost locked in right at 15lbs (from 16-17 before). Had no knock until about halfway throught 2nd gear, which reported as follows:
o2-->839.....041
KR-->5.4*.....041

Guess you didnt read. Do your tests in 3rd gear. Do not do tests when the transmission has to shift.

If you must do the test in 2nd gear, place the gear selector in 2nd.. this eliminates noise that happens when the trans shifts.

If you get knock, keep reducing boost until there is no more KR.

 

[gnx139]

Are you able to get some 100 or 104 unleaded and run 5 gallons of that in your tank. That is a simple way to eliminate octane issues from the puzzle. Or mix Xylene in your gas as it is 114 octane per gallon.

 

[kTrainHurricane]

so i got boost down to 14lbs, rolled into it from 3rd gear, and NO KNOCK!!!

However, while on the highway tonight i tried again because i only took the car up to about 65-70mph the first time. again, i rolled into it from 3rd gear at around 55mph, knock was at a steady 0, then hopped up to 4.2*, then dropped back to 0. Scanmaster readings were as follows:
o2-->804 @ 093
KR-->4.2*@ 070

 

[Razor]

Great. Any knock that pops up and disappears is false. meaning stuff banging around.

So if it does a clean pull.. then your fine. Now chase down whats cuasing the false knock.. and your ready for octane and turning the boost up.

 

[kTrainHurricane]

so here's the new recent bad news:

after having turned the boost down to 14lbs and receiving no knock as stated before, i was informed that i'm supposed to mash the gas while in 3rd gear instead of slowly getting on it. So, i did that "new" test today and received some unpleasant numbers. This test was done on the highway in 3rd gear D from about 60-65mph up until about 75. Numbers were as follows:
o2-->601 @ 063
KR-->16.4* @ 070

WHY?!

 

[FreeBoost]

where was the head cracked at, why not just pick up a used one and have the head rebuilt there is nothing special about them, could have possible other issues like bent valve stem, warped or was this head looked at closely. What also caused this crack and if you have tranny issues this could cause possible knock issues.

He said header, not head.

 

[Razor]

so here's the new recent bad news:

after having turned the boost down to 14lbs and receiving no knock as stated before, i was informed that i'm supposed to mash the gas while in 3rd gear instead of slowly getting on it. So, i did that "new" test today and received some unpleasant numbers. This test was done on the highway in 3rd gear D from about 60-65mph up until about 75. Numbers were as follows:
o2-->601 @ 063
KR-->16.4* @ 070

WHY?!

If it doesnt knock when you roll into it and does when you stab it.. both conditions same boost then you have false knock.

If your fuel system supports the boost.. it doesnt care whether you roll into it or mash the pedal. meaning when you mash the pedal the motor torques over harder.. this cuases something to bang somewhere and you get knock.

Like for instance a bad motor mount.

 

[kTrainHurricane]

thanks for the input!