BLUF: I wanted to here opinions about knock count and causes: I'm running COBB's 91 Octane Stage 1 tune (car is filled with 93 Octane) and will see Knock count on Cylinder number 3 sometimes increment to 12-15 counts when puttering around especially on take-off(results in Ignition correction of -4 to -7 degrees). On an 2nd or 3rd gear pull I will not see any consistent knock counts on any cylinder (maybe 1 or 2 randomly on one of the cylinders) and normally positive ignition corrections. MY OAR is consistently at -1. All indications of False knock? Should I be worried?
In Depth: I have a 17 Focus RS, currently running a Scorpion CBE, Mountune recirculation valve, depo racing intake, full Radium Catch Cans, and Powerflex RMM bushing insert. I've had the Head Gasket TSB done and the subsequent timing chain oil leak fixed. I recently decided warranty be damned, I'm going to use my Accessport sitting in my drawer and enjoy the car a bit more. I want to be conservative to start, so I flash the COBB 91 Octane Stage 1 Tune, even though I only ever fill up with 93 octane. Load up my monitors to see knock count for each cylinder and overall OAR.
On any 2nd or 3rd ear pull I consistently see no or 1-2 knock counts on a single cylinder. OAR is hard -1 and ignition corrections on cylinder 3 are consistently positive. All good happy signs.
Puttering around town I'll routinely see knock counts on cylinder 3 of 12-15 counts, especially on take-off in 1st gear. The car will pull cylinder 3 timing and Ignition Correction will show sometimes up -7 degrees. The other cylinders I won't see any knock or ignition corrections, only cylinder 3.
I pulled the plugs and everything looks good. I swapped the plug and coil from cylinder 2 into cylinder 3. No changes.
All indications I can draw are this is a case of false knock. The extremely high knock counts under minimal load, the 91 octane tune knocking on a single cylinder with 93 octane gas. I know our engines have two knock sensors, what I don't know is if the computer correlates piston position to knock to try and identify which cylinder the knock is coming from, or if it's simpler and related to approximate position of the sound in the block.
I don't like how the depo intake mounts, eliminating the rubber grommets and mounting directly to the motor. I also think the split between the two aluminum intake pipes is too close and the aluminum pipes could be rubbing/shifting against each other underneath the silicone connector. I plan to remove the intake and go to a Mountune intake as soon as I can find time to see if this helps. I checked my catch cans and they are tight without any rubbing I could notice.
I feel like I may be on a wild goose chase, but I'm also worried there may be something more serious going on. I don't have logs at this moment. I'm looking for everyone's thoughts on what is going on and additional troubleshooting if it persists after the intake swap. I know on other ecoboost platforms false knock is something that occurs.
Thanks in advance
In Depth: I have a 17 Focus RS, currently running a Scorpion CBE, Mountune recirculation valve, depo racing intake, full Radium Catch Cans, and Powerflex RMM bushing insert. I've had the Head Gasket TSB done and the subsequent timing chain oil leak fixed. I recently decided warranty be damned, I'm going to use my Accessport sitting in my drawer and enjoy the car a bit more. I want to be conservative to start, so I flash the COBB 91 Octane Stage 1 Tune, even though I only ever fill up with 93 octane. Load up my monitors to see knock count for each cylinder and overall OAR.
On any 2nd or 3rd ear pull I consistently see no or 1-2 knock counts on a single cylinder. OAR is hard -1 and ignition corrections on cylinder 3 are consistently positive. All good happy signs.
Puttering around town I'll routinely see knock counts on cylinder 3 of 12-15 counts, especially on take-off in 1st gear. The car will pull cylinder 3 timing and Ignition Correction will show sometimes up -7 degrees. The other cylinders I won't see any knock or ignition corrections, only cylinder 3.
I pulled the plugs and everything looks good. I swapped the plug and coil from cylinder 2 into cylinder 3. No changes.
All indications I can draw are this is a case of false knock. The extremely high knock counts under minimal load, the 91 octane tune knocking on a single cylinder with 93 octane gas. I know our engines have two knock sensors, what I don't know is if the computer correlates piston position to knock to try and identify which cylinder the knock is coming from, or if it's simpler and related to approximate position of the sound in the block.
I don't like how the depo intake mounts, eliminating the rubber grommets and mounting directly to the motor. I also think the split between the two aluminum intake pipes is too close and the aluminum pipes could be rubbing/shifting against each other underneath the silicone connector. I plan to remove the intake and go to a Mountune intake as soon as I can find time to see if this helps. I checked my catch cans and they are tight without any rubbing I could notice.
I feel like I may be on a wild goose chase, but I'm also worried there may be something more serious going on. I don't have logs at this moment. I'm looking for everyone's thoughts on what is going on and additional troubleshooting if it persists after the intake swap. I know on other ecoboost platforms false knock is something that occurs.
Thanks in advance
