False knock-motor mount

[CraiMart]

Been chasing a false knock for over a year now. Zip tied about everything loose I can find😅 Yesterday I was looking again and tried moving the motor a bit to see if I could hear anything. Moving it side to side I can hear a slight squeak. No clunking, just a slight squeak. Could that be enough when on the road to make a false knock? I’ll register knock sometimes just blipping the throttle to put it into first or when already in first just rolling. Don’t have to be pulling at all to get it sometimes.

Other possibilities I thought of: the cover for the timing belt has a split in the middle horizontally. It’s still fastened with bolts.

I put a gates water pump on it when changing the timing belt. Have heard the pump can cause knock. Not finding any signs of that on mine though. Regardless I could kick myself because I did buy a motorcraft pump aside from the belt kit but in the midst of the work I mixed up the pumps and put the gates one on. Still have the motorcraft.

Maybe the turbo heat shield. Being held on by 2 upper bolts only. Thoroughly inspected it though and don’t see it making contact.

My new tuner says because of the VERY mild tune it has, he’s certain it’s false knock. Probably going to desensitize the knock sensors a small amount to remedy this.

Still, for my own OCD, id like to figure it out.

Thanks for any input you guys

 

[thecman02]

What is you car setup? At one point I had some residual oil in the stock intercooler piping that would would get sucked into the engine and cause occasional knock. I ended up cleaning out my intercooler piping, and intercooler to resolve the issue. I would be dumbfounded if it was from a cracked timing belt cover unless the belt is some how slapping it during aggressive revving.

Usually only solid motor mounts, or broken motor mounts will get picked up on a knock sensor, and usually solid motor mounts contribute such a consistent noise on the input, that it won't get flagged by the ECU's knock count algorithm.

 

[CraiMart]

Sorry o

What is you car setup? At one point I had some residual oil in the stock intercooler piping that would would get sucked into the engine and cause occasional knock. I ended up cleaning out my intercooler piping, and intercooler to resolve the issue. I would be dumbfounded if it was from a cracked timing belt cover unless the belt is some how slapping it during aggressive revving.

Usually only solid motor mounts, or broken motor mounts will get picked up on a knock sensor, and usually solid motor mounts contribute such a consistent noise on the input, that it won't get flagged by the ECU's knock count algorithm.

Sorry I should have put that.

Mishimoto charge pipes
Mountune induction hose
Ramair crossover pipe
Mishimoto intercooler
St 200 air box
Ramair drop in air filter
Cobb RMM
Turbo technics S280 turbo
tune+ Turbosmart waste gate actuator
GFB DV+
Whoosh catted 3” downpipe
R&D 3” catback exhaust

that’s very interesting about the residual oil. I would have never thought about that. Is that something that should be done periodically? Cleaning those items out?

 

[dhminer]

Is it just cylinder 1 showing knock? Stock passenger side motor mount?

 

[thecman02]

Any time you get oil into the combustion chamber you have the chance for knock/preignition and even misfires.
When I first got my s280 I had a couple episodes of oil getting into my intercooler and piping. I'm assuming it was a bad PCV, but I just put in a Damond Catch can with the one way valve on and it eliminated my issues with oil getting where I didn't want it. Here's a lil info on our PCV system, https://dizzytuning.com/blogs/technical-documents/fiesta-st-1-6l-ecoboost-pcv-system

Also, I had a COBB RMM and i couldn't really get it to deflect with a prybar, but I noticed wheel hop starting to creep back into the car. When I took off the motormount I saw the bushing was ovaled out. Not sure they have replacement bushings for sale. I ended up getting a different RMM. I don't know if yours might be worn out enough to be knocking, but with worn oem psmm and dsmm, and a worn out cobb rmm it might be enough to get you noise picked up on the knock sensor.

My money is still on oil getting ingested though.

 

[CraiMart]

Is it just cylinder 1 showing knock? Stock passenger side motor mount?

It happens randomly in all cylinders. Sometimes just one and sometimes all of them. Yesterday I was on the highways at about 2500ish rpm, just maintaing speed, hit about 1 pound of boost and started pulling timing in 3 and 4 cyl.

 

[CraiMart]

Any time you get oil into the combustion chamber you have the chance for knock/preignition and even misfires.
When I first got my s280 I had a couple episodes of oil getting into my intercooler and piping. I'm assuming it was a bad PCV, but I just put in a Damond Catch can with the one way valve on and it eliminated my issues with oil getting where I didn't want it. Here's a lil info on our PCV system, https://dizzytuning.com/blogs/technical-documents/fiesta-st-1-6l-ecoboost-pcv-system

Also, I had a COBB RMM and i couldn't really get it to deflect with a prybar, but I noticed wheel hop starting to creep back into the car. When I took off the motormount I saw the bushing was ovaled out. Not sure they have replacement bushings for sale. I ended up getting a different RMM. I don't know if yours might be worn out enough to be knocking, but with worn oem psmm and dsmm, and a worn out cobb rmm it might be enough to get you noise picked up on the knock sensor.

My money is still on oil getting ingested though.

I’ll check out both of those. Thanks!

 

[TyphoonFiST]

I’ll check out both of those. Thanks!

And what were the findings?

 

[CraiMart]

And what were the findings?

So far I took off the ECU and opened it to see if there was anything burning. No black marks on the inside. I noticed that 4 of the pins on the ECU connection are a darkened copper coller though. Along with this I found on cylinder 3, on one of the 3 spark plug wires to the connector, there is a smal cut exposing the wire. Also on one of the wires to the connector for the HPFP. Fuel pressure has been reading good on the HPFP. I know that for the break in the spark plug wire it can cause the spark to hit other metal parts before going to the plug. Could that possibly cause the crazy fluctuations in knock that i'm getting through all cylinders? I'm still trying to go through all the connectors to see if I see anything else.