False knock....where to look?

[PunkST]

I get false knock if I accelerate at low rpm while turning left. No problems turning right

A gallon or two every 2-3 fill ups makes most of my negative corrections go away.

I wonderter if your upper trans mount is weakened.

 

[TyphoonFiST]

It would be worth checking it out!

Sent from my SM-N950U1 using Tapatalk

 

[TyphoonFiST]

I wonder if they changed the bolt design to avoid rounding due to over Torquing at the factory? This is the Rear most RMM bolt that goes thru Cradle mount into and out THE RMM. Just a tidbit of info....

Sent from my SM-N950U1 using Tapatalk

 

[Clint Beastwood]

I wonderter if your upper trans mount is weakened.

Might be - recently noticed the following:
When pulling out of a parking spot, wheel cranked completely to the left, car in gear, as I let off the clutch and first start moving it feels like there is a LOT of movement in the drivetrain. I also kinda feel a wobble or "hitching" when doing full-lock left turns. Have not had time to investigate.

 

[TyphoonFiST]

Might be - recently noticed the following:
When pulling out of a parking spot, wheel cranked completely to the left, car in gear, as I let off the clutch and first start moving it feels like there is a LOT of movement in the drivetrain. I also kinda feel a wobble or "hitching" when doing full-lock left turns. Have not had time to investigate.

What is your conclusion there Clitsky?

 

[Clint Beastwood]

What is your conclusion there Clitsky?

Haven't had time to investigate it much, been busy doing a pretty time consuming legal "thing".

 

[JDG]

Hey @TyphoonFiST , did you ever get this sorted? I am dealing with a similar issue right now and am leaning towards the Passenger side engine mount being the culprit. I am seeing as many as 6 knock events on cylinder 1 only on straight E85 with minimal timing. The other cylinders are perfectly fine with this timing. I also noticed a bit of increased torque steer recently (car likes to wander/tram line under throttle more so than usual).

I have the vibra technics fast road mounts en route so hopefully that solves it but I was wondering if you ever found a solution yourself.

Thanks!

 

[JDG]

Hey @TyphoonFiST , did you ever get this sorted? I am dealing with a similar issue right now and am leaning towards the Passenger side engine mount being the culprit. I am seeing as many as 6 knock events on cylinder 1 only on straight E85 with minimal timing. The other cylinders are perfectly fine with this timing. I also noticed a bit of increased torque steer recently (car likes to wander/tram line under throttle more so than usual).

I have the vibra technics fast road mounts en route so hopefully that solves it but I was wondering if you ever found a solution yourself.

Thanks!

Here is what I have investigated so far without success in trying to find the reason for cylinder 1 knocking on E85 but the others not knocking at all:

1. Reterminated posi-tap connections for aux fuel, some were lose but no change
2. Swapped coil pack from cylinder 1 and 2
3. Removed plug on ST200 intake box for the bottom hose (thought maybe I was starving the engine of air)

Future troubleshooting in order (test after each change):

1. Swap cylinder 1 and 2 spark plugs
2. Change out passenger side engine mount to vibratechnics
3. Remove oem exhaust manifold heat shield (might be rattling around?) since it is only secured by two top bolts
4. Check for contact of components near turbo (investigate using OEM downpipe bracket on whoosh downpipe)
5. Remove skid plate
6. Install vibratechnics driver side engine mount
7. Replace CP-E lower engine mount with stock
8. Replace cylinder 1 direct injector with new injector (need to purchase) to rule out clogged injector

Thanks to @TyphoonFiST and @morton1 for helping me troubleshoot so far. Any further ideas are appreciated.

I still believe it is false knock because I have run 50-60% more timing on E50 in the past without this kind of knock (~8 months ago on the GTX turbo).

 

[JDG]

Hey @TyphoonFiST , did you ever get this sorted? I am dealing with a similar issue right now and am leaning towards the Passenger side engine mount being the culprit. I am seeing as many as 6 knock events on cylinder 1 only on straight E85 with minimal timing. The other cylinders are perfectly fine with this timing. I also noticed a bit of increased torque steer recently (car likes to wander/tram line under throttle more so than usual).

I have the vibra technics fast road mounts en route so hopefully that solves it but I was wondering if you ever found a solution yourself.

Thanks!

Here is what I have investigated so far without success in trying to find the reason for cylinder 1 knocking on E85 but the others not knocking at all:

1. Reterminated posi-tap connections for aux fuel, some were lose but no change
2. Swapped coil pack from cylinder 1 and 2
3. Removed plug on ST200 intake box for the bottom hose (thought maybe I was starving the engine of air)

Future troubleshooting in order (test after each change):

1. Swap cylinder 1 and 2 spark plugs
2. Change out passenger side engine mount to vibratechnics
3. Remove oem exhaust manifold heat shield (might be rattling around?) since it is only secured by two top bolts
4. Check for contact of components near turbo (investigate using OEM downpipe bracket on whoosh downpipe)
5. Remove skid plate
6. Install vibratechnics driver side engine mount
7. Replace CP-E lower engine mount with stock
8. Replace cylinder 1 direct injector with new injector (need to purchase) to rule out clogged injector

Thanks to @TyphoonFiST and @morton1 for helping me troubleshoot so far. Any further ideas are appreciated.

I still believe it is false knock because I have run 50-60% more timing on E50 in the past without this kind of knock (~8 months ago on the GTX turbo).

@slopoke @Perfblue15 if you guys are still around, can you provide some input? I think I found some old thread threads searching the forum where you both had chased similar issues in the past when you were running big turbos.

 

[slopoke]

@slopoke @Perfblue15 if you guys are still around, can you provide some input? I think I found some old thread threads searching the forum where you both had chased similar issues in the past when you were running big turbos.

I did not have those issues with my Fiesta. I know some that have had their tuners reduce the sensitivity of the knock sensors to address this problem. IIRC that the #1 cylinder is the one closest to the passenger side and the belt driven accessories are located there. You might want to look at that area for any problems, water pump, pulleys, alternator, etc. Good luck.

 

[JDG]

I did not have those issues with my Fiesta. I know some that have had their tuners reduce the sensitivity of the knock sensors to address this problem. IIRC that the #1 cylinder is the one closest to the passenger side and the belt driven accessories are located there. You might want to look at that area for any problems, water pump, pulleys, alternator, etc. Good luck.

Yeah, cylinder 1 is the passenger side. And good call, Mitch mentioned checking belt tension of the serpentine belt. I will take a look at all the other rotating stuff over there too. Not hearing anything noticeable though. The knock events happen between 5K-7K RPM too and increase pretty rapidly. Super weird considering the other cylinders don't move from 0.

 

[lowda9]

I use to think that all my negative corrections were false knock..I'd get random -2.5 all the time when starting from a stop and negative corrections all over the place in 4th gear. Then I put a gallon of e85 in it and I didn't get a single negative correction for the whole tank. Our canadian fuel is rated to be up to e10 so putting a gallon of e85 brings it up approximately to e15. The e85 made a huge difference for me.

 

[TemecFist]

It seems like everything and anything can cause false knock. Lol

 

[slopoke]

JDG, what turbo are you running?

 

[JDG]

JDG, what turbo are you running?

S280

 

[slopoke]

Did you check the clearance between the compressor housing and the block? I'd check the housing to see if there are any contact marks on the compressor case, due to possible movement of the turbo. I know when I installed my S240, I had around a 1/4" in clearance after I ground the boss down.

 

[JDG]

Did you check the clearance between the compressor housing and the block? I'd check the housing to see if there are any contact marks on the compressor case, due to possible movement of the turbo. I know when I installed my S240, I had around a 1/4" in clearance after I ground the boss down.

I will check again but I hacked out a lot of material there before the install so there was a bunch of clearance. Solid idea nonetheless.

Edit: plenty of space, this is not the issue. I secured the exhaust manifold heat shield a bit better today.

 

[JDG]

UPDATED TROUBLESHOOTING LIST

Starting to think this is real knock..

Here is what I have investigated so far without success in trying to find the reason for cylinder 1 knocking on E85 but the others not knocking at all:

1. New posi-tap connection for aux fuel cylinder 1, fixed the remaining lose connections
2. Swapped coil pack from cylinder 1 and 2
3. Removed plug on ST200 intake box for the bottom hose (thought maybe I was starving the engine of air)
4. Swapped spark plugs 1 and 3, no change
5. Upgrade passenger side engine mount to vibra-technics, decreased torque steer but no change to knock count
6. Secure OEM exhaust manifold heat shield with lower bolt, no movement, no change to knock
7. Nothing is making contact near the engine/knock sensors
8. Removed skid plate, no change

To be completed next week (engine mount is en route and injector just ordered)

1. Replace cylinder 1 direct injector with new injector
2. Use boroscope in cylinder 1 to look for piston damage or evidence of knock
3. New Brisk Racing spark plug in cylinder 1 (Replace Brand New NGK 6510)
4. Compression test
5. Replace CP-E lower engine mount with another upgraded unit (although no movement detected from CP-E unit)

Reallyyyy hoping it is just a clogged injector since I have pretty much ruled out everything else.

 

[wetwea33]

UPDATED TROUBLESHOOTING LIST

Starting to think this is real knock..

Here is what I have investigated so far without success in trying to find the reason for cylinder 1 knocking on E85 but the others not knocking at all:

1. New posi-tap connection for aux fuel cylinder 1, fixed the remaining lose connections
2. Swapped coil pack from cylinder 1 and 2
3. Removed plug on ST200 intake box for the bottom hose (thought maybe I was starving the engine of air)
4. Swapped spark plugs 1 and 3, no change
5. Upgrade passenger side engine mount to vibra-technics, decreased torque steer but no change to knock count
6. Secure OEM exhaust manifold heat shield with lower bolt, no movement, no change to knock
7. Nothing is making contact near the engine/knock sensors
8. Removed skid plate, no change

To be completed next week (engine mount is en route and injector just ordered)

1. Replace cylinder 1 direct injector with new injector
2. Use boroscope in cylinder 1 to look for piston damage or evidence of knock
3. Replace CP-E lower engine mount with another upgraded unit (although no movement detected from CP-E unit)

Reallyyyy hoping it is just a clogged injector since I have pretty much ruled out everything else.

Have you done a compression/leak down test yet? To me this 100% seems like false knock. Hunting stuff like this down can be a huge bitch.

Sent from my SM-G975U using Tapatalk

 

[JDG]

Have you done a compression/leak down test yet? To me this 100% seems like false knock. Hunting stuff like this down can be a huge bitch.

Sent from my SM-G975U using Tapatalk

I'll add that to the list. The boroscope showed up yesterday so sometime this week I am going to inspect the cylinder bores of each cylinder to compare as well as the piston tops to look for evidence of knock. Mitch is thinking it's false knock as well.