Knock?

jjorgensen52

NHSTE - I'm the only one!
Did a big burnout tonight and a few boost launches, afr about 12 and datamaster indicating little knock and one instance of 0.5* of retard. But afterwards, driving it home, I was getting massive knock and as much as 12* of retard just lightly on the gas to get on the highway ? I am confused as to why this would happen... i was not recording on DM at the time the knock occured. Also, could it be linked to the fact that the truck has started to run richer, 11.5 - 12.5 afr cruising on the highway?
 

jjorgensen52

NHSTE - I'm the only one!
Re: Knock?

MikeRenz said:
record it and post the files.
Will do if it's still happening tomorrow. Going to wrap my drivers header in the morning, then I'm driving it to a concert so I can get some DM then.
 

jjorgensen52

NHSTE - I'm the only one!
Re: Knock?

where do you folks host DM files? putfile doesnt like them. I have a file from my trip home today, but can't upload it anyplace apparently
 

jjorgensen52

NHSTE - I'm the only one!
Re: Knock?

Aside from the massive knock counts and retard, the thing that bothers me the most about this is that the truck is never going into closed loop. Side effect of which is that the AFR stays down around 11, sometimes even 10's on the highway at cruising speed. It comes up to about 13.5 - 14 at idle in gear, about 850 rpm, but thats the only time it feels right
 

MikeRenz

not stock
Re: Knock?

wow....that's an ugly file

how much timing are you trying to throw at this thing. 30-35degrees of spark advance....only goes back to 10degrees under knock. Seems like a lot to me :dunno: Have you double checked your flexplate bolts again? You get knock any time you give it any throttle - i wonder if its your flexplate or your tc acting up. Where is your knock sensor located - stock location?
 

QUICK STORM

B.A.M.F. BMW Tech
Re: Knock?

in another thread you said that you got NO knock when the engine was running on the dyno, right?

now insert transmission/torque converter, and you get knock. sense anything?

i agree with mike, must have something to do with whatever is behind the engine.
 

jjorgensen52

NHSTE - I'm the only one!
Re: Knock?

QUICK STORM said:
in another thread you said that you got NO knock when the engine was running on the dyno, right?

now insert transmission/torque converter, and you get knock. sense anything?

i agree with mike, must have something to do with whatever is behind the engine.
the engine doesnt sound right either, but it's not terrible. I just checked the flexplate bolts and TC yesterday, they're good. I wonder if the fuel lines are knocking on the sensor or something (yes stock location) ...actually, come to think of it, could a bad ground at the knock sensor cause it to do weird stuff? Also, do you guys think that the drop in the AFR all around is related or a seperate problem?

it's set at 4 degrees adv. with the timing connector off, also

Also, the dyno runs were perfectly smooth. We had nice AFR's and no knock whatsoever in all the pulls we did, it ran smooth as silk
 
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