Cruise Knock Issue

[gm5oh]

Hello all,

I am having an issue with knock at cruise but none any reoccurring at WOT. I've sent countless logs to my tuner and we have tried to pull timing at those areas but it seems that the cruise knock (knock corr. + flkc) continues to come back. I've ensured that there is nothing in my engine bay that could be causing this knock reading. I do want to mention that I do not recall this happening during Fall / Winter times last year. I do live in south Florida, so the heat could be the cause of the issue, but then again, the intake comp table should take care of this. Something important things to note is that this problem occurs on 93 + e85, I have never seen flkc or knock corr. be any less than -2, my car is tuned via OFT, and it does not always happen. I have had a hard time recreating this issue while the motor is cold during cruise.

If you could please take a look at the following logs and let me know how to troubleshoot this / let me know if this is something to even worry about I would greatly appreciate it!

Logs:

• https://datazap.me/u/ginomuto/slight...&data=1-4-5-12

• https://datazap.me/u/ginomuto/knock-...=0&data=1-5-12

• https://datazap.me/u/ginomuto/knock-...=0&data=1-5-12

• https://datazap.me/u/ginomuto/knock-...=0&data=1-5-12

EDIT:
FP + OP is this close to sway bar. Not sure if it would have that much play, however.

[steve99]

very likely that knock may be due to mechanical rattle or vibration of exhaist on chassis or skid plate fooling knock sensor


Pull 5 degrees out of the entire base b timing map


if knock doesnt change then its very likely rattle vibration problem its a common issue


if the knock goes away with 5 degrees out of the map then likely fueling ignitin timing issue

[Kodename47]

TBH if it's at cruise then it's not really an issue, not enough cylinder pressure. It's almost impossible to completely stop any form of knock correction triggering and you can ruin the feel of the car doing so. Let the ECU pull timing if it wants in lower load, that's what it's designed to do.

[gm5oh]

Thank you, I'll reply again soon when / if I find a solution.

[gm5oh]

Originally Posted by steve99

very likely that knock may be due to mechanical rattle or vibration of exhaist on chassis or skid plate fooling knock sensor


Pull 5 degrees out of the entire base b timing map


if knock doesnt change then its very likely rattle vibration problem its a common issue


if the knock goes away with 5 degrees out of the map then likely fueling ignitin timing issue

Hey Steve, I am pretty sure I've narrowed down my cruise knock to having UEL headers, no factory heat shields, and being down in South Florida where it is really hot 75% of the year. I do not have header wrap because I don't want my headers to crack and in the event I have an oil leak, I do not want my car up in flames.

Note: Before I got an oil cooler, after doing some light pulls I would get to oil temps of upwards 240+ degrees Fahrenheit. It wouldn't take me any more than 3 minutes driving to get to 185 degrees Fahrenheit.

Tagging @Kodename47 so he sees this too. What do you guys recommend? I was thinking of wrapping my OP + FP in header wrap, but I am hesitant that my OP / FP could crack.

Please let me know what you think

[steve99]

Originally Posted by gm5oh

Hey Steve, I am pretty sure I've narrowed down my cruise knock to having UEL headers, no factory heat shields, and being down in South Florida where it is really hot 75% of the year. I do not have header wrap because I don't want my headers to crack and in the event I have an oil leak, I do not want my car up in flames.

Note: Before I got an oil cooler, after doing some light pulls I would get to oil temps of upwards 240+ degrees Fahrenheit. It wouldn't take me any more than 3 minutes driving to get to 185 degrees Fahrenheit.

Tagging @Kodename47 so he sees this too. What do you guys recommend? I was thinking of wrapping my OP + FP in header wrap, but I am hesitant that my OP / FP could crack.

Please let me know what you think

its unlikely its due to heat from headers many people run caltess header no shield, it more likely due exhaust hitting on chassis or shid plate