Jordan_R
Stock Block Ready To Knock...er..Rock
I figured I would throw up a source of false knock trouble shooting thread. This is under the assumption your fueling is perfect and a non issue. If not listed below add it in the comments and I will add it to the list.
What is Knock? Knock is when the knock sensors, which are basically tiny little microphones, pick up a ping, rattle or something along those lines which can be interpreted as fuel pre-ignition. When the knock sensors pick up knock it pulls timing because the car is under the assumption that the fuel is igniting before it's suppose to be due to lower octane compared to how much timing you are running (higher octane equals ability to run more timing in simple terms)
While you might not get knocks at WOT there are several instances of part throttle/specific RPM knock listed below that can throw off your OAR if your tuner uses that in their tuning style. Sources of false knock in a somewhat common to least common list on the 3.5L Transverse ecoboost platform:
1) Knock Sensor Chaffing - Front Right side of intake manifold by the thermostat is where the knock sensors can chaff and cause false knock. Sleeve with rubber hose and zip tie out of way.
2) Transmission mounts lower or upper - There is 3 transmission mounts with 2 being on the underside of the car and 1 being on the top of the transmission. Over time these can wear out and cause false knock under load.
3) Loose exhaust/ heat shield - remember how I said these little microphones listen for metal noises? Same thing here. Make sure all exhaust components are not rubbing / loose.
4) Exhaust Rasp - I had this happen where my exhaust itself from being extremely raspy at a distinct rpm range was causing false knock. It was completely repeatable with a part throttle RPM sweep.
5) EPP Hot pipes mounting - Normally these don't have a bushing on the pipe that has the BOVs and hard mounts to the intake manifold. Use a rubber isolator or fuel line and sleeve the prongs on the mount to make it rubber mounted. ALSO NOTE: if your aftermarket pipes are pushed into the couplers too far the pipes can hit together also causing false knock if the knock sensors can pick it up. An example of a spot that could happen is the noisemaker delete off of the throttle body rattling against the throttle body itself.
6) Undershield - there has been cases of the undertray being lose on one of the mounts causing false knock
7) Bad Oxygen Sensors - while this isn't a very common one I've heard of instances where an oxygen sensors not being accurate was causing false knock readings. Need more information on this one to confirm completely.
8) Engine mount - there has been an instance or two recorded where the engine mount was causing false knock.
What is Knock? Knock is when the knock sensors, which are basically tiny little microphones, pick up a ping, rattle or something along those lines which can be interpreted as fuel pre-ignition. When the knock sensors pick up knock it pulls timing because the car is under the assumption that the fuel is igniting before it's suppose to be due to lower octane compared to how much timing you are running (higher octane equals ability to run more timing in simple terms)
While you might not get knocks at WOT there are several instances of part throttle/specific RPM knock listed below that can throw off your OAR if your tuner uses that in their tuning style. Sources of false knock in a somewhat common to least common list on the 3.5L Transverse ecoboost platform:
1) Knock Sensor Chaffing - Front Right side of intake manifold by the thermostat is where the knock sensors can chaff and cause false knock. Sleeve with rubber hose and zip tie out of way.
2) Transmission mounts lower or upper - There is 3 transmission mounts with 2 being on the underside of the car and 1 being on the top of the transmission. Over time these can wear out and cause false knock under load.
3) Loose exhaust/ heat shield - remember how I said these little microphones listen for metal noises? Same thing here. Make sure all exhaust components are not rubbing / loose.
4) Exhaust Rasp - I had this happen where my exhaust itself from being extremely raspy at a distinct rpm range was causing false knock. It was completely repeatable with a part throttle RPM sweep.
5) EPP Hot pipes mounting - Normally these don't have a bushing on the pipe that has the BOVs and hard mounts to the intake manifold. Use a rubber isolator or fuel line and sleeve the prongs on the mount to make it rubber mounted. ALSO NOTE: if your aftermarket pipes are pushed into the couplers too far the pipes can hit together also causing false knock if the knock sensors can pick it up. An example of a spot that could happen is the noisemaker delete off of the throttle body rattling against the throttle body itself.
6) Undershield - there has been cases of the undertray being lose on one of the mounts causing false knock
7) Bad Oxygen Sensors - while this isn't a very common one I've heard of instances where an oxygen sensors not being accurate was causing false knock readings. Need more information on this one to confirm completely.
8) Engine mount - there has been an instance or two recorded where the engine mount was causing false knock.
