Using Accessport to track Knock?

Gonna start this with stating that I'm paranoid. I recently swapped my spark plugs out for a set from Tune+ (pre gapped). A few days ago I head what I can only describe as a knocking sound under load at around 4k rpm. It happened when the car was cold but I've heard it again when it car was warmer. Of course I was in a panic at this point.

I currently have my AP monitoring the knock PI Rate but I'm not 100% sure this will show me what I want to see. I'm gonna take these spark plugs out asap and check the gaps. Anyone got any ideas what I'm hearing? I'll post video if I can get a chance but obviously I'm not pushing my car right now.

Monitor ignition corrections that will show you where you have issues. You can do Cyl1-4 if you want to. I do 1 and 3.

chadhtx40 said:

Monitor ignition corrections that will show you where you have issues. You can do Cyl1-4 if you want to. I do 1 and 3.

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I have been datalogging the past few days, I honestly don't know how to read the ignition correction. What is good? what is bad? is anything negative bad or am I looking for as close to 0 as possible?

I agree that you want to monitor ignition corrections. Generally speaking, positive is good and negative is bad. Seeing a little bit of negative is completely normal every once in a while under part throttle, but you want to watch for negative corrections under WOT. Usually what you'd want to see during a datalog is the corrections gradually increase until they hit a specified number (this number will vary based on your tune) and then stay at that number for the remainder of the pull. From my understanding, this value shows the ECU adding or pulling timing based on feedback from the knock sensors. If you're seeing negative numbers during multiple WOT pulls then you may have gotten a bad tank of gas.

There is tables specific to knock. On your accessport, set 4 of the windows to knock count. That will tell you if the vehicle is actually knocking, how hard it is knocking, and on what specific cylinder. Ignition correction is fine, but watch knock count if that is specifically what you are worried about.

MustangEcoboosted said:

There is tables specific to knock. On your accessport, set 4 of the windows to knock count. That will tell you if the vehicle is actually knocking, how hard it is knocking, and on what specific cylinder. Ignition correction is fine, but watch knock count if that is specifically what you are worried about.

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This is incorrect.

Knock Count just monitors the instances of knock you have. In other words, if Cylinder #3 knocks 4 times, then it'll display a 4.00 for that cylinder. It does not in any way, shape, or form show the intensity of the knock (how bad it is). For that, you need to monitor Ignition Corrections.

Ignition Corrections show you when knock is happening and how strong the knock is in intensity. Every car will knock a little, even on a stock tune, but what you want to monitor is Ignition Corrections for Cylinders 1-4 under WOT. If it's greater than -2.00 for more than brief instances, then you should get some datalogs looked at by your tuner. Optimally, you'd want the corrections to be positive, such as +3.25, but like I said, all engines knock a little from time to time. A lot of variables can influence that as well.

Go into the monitors and set it to monitor Ign. Corr. Cyl. 1-4. That'll show you all you need to know. You can record those in a datalog too and really see what it's doing over the course of a 3rd gear pull.

Juben said:

Go into the monitors and set it to monitor Ign. Corr. Cyl. 1-4. That'll show you all you need to know. You can record those in a datalog too and really see what it's doing over the course of a 3rd gear pull.

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/thread

Garf said:

Gonna start this with stating that I'm paranoid. I recently swapped my spark plugs out for a set from Tune+ (pre gapped). A few days ago I head what I can only describe as a knocking sound under load at around 4k rpm. It happened when the car was cold but I've heard it again when it car was warmer. Of course I was in a panic at this point.

I currently have my AP monitoring the knock PI Rate but I'm not 100% sure this will show me what I want to see. I'm gonna take these spark plugs out asap and check the gaps. Anyone got any ideas what I'm hearing? I'll post video if I can get a chance but obviously I'm not pushing my car right now.

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I would strongly recommend NOT doing that. These little 4 cyl DI turbo engines are sensitive. You really should wait until the engine has warmed up completely before any load. Not when the temp gauge says the coolant has warmed up because that happens quicker, when the oil temp has warmed up which is usually a few minutes longer than the coolant. This way everything is oiled properly.

Sometimes I wonder how many of the blown engine stories are because people are giving it too much before the engine has warmed up completely. Think about it, most of the time we hear "I was just accelerating a little to get on the highway", "I wasn't on it hard" stuff like that. Nobody ever says I started the car, put it in gear and floored it but it doesn't take much. If you've ever had your charge pipe blow off, you know how very little this engine has without the turbo, you really should go easy on it. Mine is a PP so I have the oil pressure gauge. When I start mine it's usually around 80 psi and even with very light load will approach 100 psi. After it warms up, it'll drop to around 30-40 psi or something like that.

Yep. Search for the Coyote OPG grenade stories with cold oil :lol:

jbailer said:

I would strongly recommend NOT doing that. These little 4 cyl DI turbo engines are sensitive. You really should wait until the engine has warmed up completely before any load. Not when the temp gauge says the coolant has warmed up because that happens quicker, when the oil temp has warmed up which is usually a few minutes longer than the coolant. This way everything is oiled properly.

Sometimes I wonder how many of the blown engine stories are because people are giving it too much before the engine has warmed up completely. Think about it, most of the time we hear "I was just accelerating a little to get on the highway", "I wasn't on it hard" stuff like that. Nobody ever says I started the car, put it in gear and floored it but it doesn't take much. If you've ever had your charge pipe blow off, you know how very little this engine has without the turbo, you really should go easy on it. Mine is a PP so I have the oil pressure gauge. When I start mine it's usually around 80 psi and even with very light load will approach 100 psi. After it warms up, it'll drop to around 30-40 psi or something like that.

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I should clarify, by cold I mean engine oil temp around 160ish (142f is min safe temp) so I'm not talking about the motor just being turned on. its just not running at 186 - 200f like it normally is during the summer days. Came to this car from a Mazdaspeed 3 so I know all about not running on a cold motor or going WOT under 3k rpm lol.

This is also why I'm paranoid! the mazda engines are very similar to this and I've read all the horror stories of tiny things causing massive problems. The burden of knowledge is so real.

[MENTION=25800]Garf[/MENTION] As I said on a different thread, on the Accessport, negative timing correction values seem to mean pulling timing and positive seem to mean adding timing. Look for this text in the following link:

https://cobbtuning.atlassian.net/wi...bile?contentId=30900388#content/view/30900388

"Negative timing corrections should remain as minimal as possible, with that said small negative timing corrections are a part of the ST's elaborate ignition control strategy. When logging all cylinders corrections under full throttle, consistent negative corrections across multiple cylinders or incremental corrections indicate excessive engine noise and is a sign that the map might be too aggressive for the mechanical condition of your vehicle."

Also go at the end of the first post in the following thread, where you will see that removing (pulling) timing is given by a negative number in ignition timing correction (-2.5 degrees in that case) using the Accessport.

http://www.fiestastforum.com/forum/...t-data-from-COBB?p=46220&viewfull=1#post46220

There is also a wonderful article that explains all this in detail:

http://stratifiedauto.com/blog/unde...ons-in-your-high-performance-ecoboost-engine/

So, ignition timing correction on the Accessport seems to mean "pulling timing" when it is negative and "adding timing" when positive. On my Accessport, apart from Charge Air Temperature, I also have ignition timing, knock count and ignition correction (all for cylinder 1) next to the OAR, for safety reasons. However I agree with [MENTION=13694]Juben[/MENTION] above that the best way to monitor knock is by monitoring ignition corrections for cyl 1-4, because this way you will know the intensity of the knock (how bad the knock is) for all cylinders. Maybe I will also use these data monitors after all

Hope this helps.