thank you, but if you had read through the thread, we've done all that. all the injectors have been replaced along with the fuel pump, and the car was retuned after the knock started. race gas and still knocking signals false knock to me. along with knock voltage not moving even when the logs show 25 counts of knock or more. i've been monitoring the coolant level for 3 weeks and there has been no change. i am trying to find out why the cylinder is clean. that's what i need help with. there are no signs of a head gasket leak, or real knock. spark plugs all look good, compression across all 4 cylinders was good. lean spool is disabled.

i didn't say AFR's aren't important, they aren't the issue though because they have been checked, tuned, checked, and retuned, and checked again. the AFR's aren't causing the knock.

also, i've run a tune just to see what would happen with less than stock boost, and just about all timing pulled, and the damn thing still knocked.

the only thing that has helped the knocking is the cleaning up the engine bay...for example, I rubber mounted the grimmspeed 3 port BCS, moved a lot of piping around so it wasn't touching anything else, etc. knock went from 25-30 counts of knock on EVERY run down to around 8-10. then I removed a rattling Ingalls stiffy and the knock went down to 4-5 counts. I can still hear some rattling under the hood, and a slight exhaust leak developed, so something is loose.

the ONLY thing that looks at all out of the ordinary is that one damn cylinder being clean. nothing else points to real knock but that.

 

To me it sounds like something is rattling. Did you check your downpipe clearance with the tie bars?

Also, when you did the compression test was the car warmed up fully?

 

yes, i even took the front tie bar off. it has one tiny tiny mark on it where the DP may have touched it once or twice, but nothing that would cause an issue. I think all of this is related to my exhaust leak. it's coming from the O2 housing/DP area under the hood, but wasn't there when I originally got the car tuned.

at the time of the original tune, the car did not knock at all. it didn't start until I got home (8 hour drive). it's hard to pinpoint, but it seemed like it didn't do any knocking until after the first time I was able to smell that exhaust leak. I'm thinking something came loose, or a gasket started leaking/blew out, and is allowing the pipe to leak/rattle. i shouldn't have ANY exhaust leaks under the hood because ALL of the exhaust components are brand new. this issue will be addressed in a week or two when it's down for the timing belt job.

I plan to do another compression check because the car wasn't full warmed up yet when I did the first one.

 

the issue kind of resolved itself, and the car is running knock free, and strong now. thanks to everyone for their help.

as for the clean piston, it must have been the seafoam because it blacked itself back again after we found it clean that day.

 

Fixed itself???
was it the knock sensor?

 

I never replaced the sensor...bought one, but forgot it at home when the work was being done. the knock just went away. I think it had to do with me rearranging the engine bay. making sure nothing was touching/rattling.