Knock on 93

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02-18-2023
reubone

Knock on 93

So I have been having an issue with my ecoboost mustang. I either have spark knock or misfire. It depends on which set of three sparkplugs I run as to which I get. Ruthenium and stock motorcraft plugs give me knock. The NGK 6510's and I get misfire. This happened after mixing a tank with boostane to give some added octane. Anything over 10-12lbs of boost and I can hear pinging and at wot Ill get -8* spark correction from spark knock which I can also hear. Any other time the engine runs just fine. Starts fine, Idles Fine, gets 33.4 mpg at 62mph. Drive great out of boost. Tried a little ethanol by getting down to 79 miles left in the tank and poured a handle of everclear 190proof in the tank.......I know I know but I was desperate to try something. Low and behold, I could now boost it with out audible knocking and pinging. What I do see though is that cyl #3 will show signes of knock retard and then another cyl will follow if not all of them. But #3 holds onto the knock retard the longest after starting the trend so.......Who thinks that possibly the balance shafts have something to do with it? Let me know your thoughts. This was a none issue before I tried the boostane 4 tanks ago.
02-19-2023
IARLLC

Back when I pulled the messed up balance shafts out of my friend's Focus ST it did not take long. So even if you decide to put them back, it is not much of a time commitment. It felt like it had gained 15HP. So if you get the same and get rid of the false knock retard I'd guess you won't be putting them back in. At least you will know for sure if the noise that the knock sensors feel comes from there.
02-19-2023
reubone

Quote:

Originally Posted by IARLLC

Back when I pulled the messed up balance shafts out of my friend's Focus ST it did not take long. So even if you decide to put them back, it is not much of a time commitment. It felt like it had gained 15HP. So if you get the same and get rid of the false knock retard I'd guess you won't be putting them back in. At least you will know for sure if the noise that the knock sensors feel comes from there.

I feel the same way about it honestly. Who else thinks we should at least try it?
02-19-2023
Seishuku

Oil feed plug is only $30, the rest is time, so not much to loose if you do it yourself.
I'd like to pull my balance shaft assembly as well, it's really not needed and I'm all about removing failure points.

Interesting that the added ethanol reduced the knock, I find it a little hard to believe that you've had bad gas this whole time... I would have expect the octane booster to do the same, but nope.
02-19-2023
reubone

I feel the exact same way. Id post the logs but you know what your going to see. One with knock and one without. I just did a compression test. 150,150,150,151. So I think i can rule out piston damagge. This test was done on an engine that sat over night so dry and cold.
05-18-2023
GenerousLemon1

You said -8 spark correction. Is that -8 KR? If so, that is not bad.
05-18-2023
Stevekreger

Quote:

Originally Posted by reubone

So I have been having an issue with my ecoboost mustang. I either have spark knock or misfire. It depends on which set of three sparkplugs I run as to which I get. Ruthenium and stock motorcraft plugs give me knock. The NGK 6510's and I get misfire. This happened after mixing a tank with boostane to give some added octane. Anything over 10-12lbs of boost and I can hear pinging and at wot Ill get -8* spark correction from spark knock which I can also hear. Any other time the engine runs just fine. Starts fine, Idles Fine, gets 33.4 mpg at 62mph. Drive great out of boost. Tried a little ethanol by getting down to 79 miles left in the tank and poured a handle of everclear 190proof in the tank.......I know I know but I was desperate to try something. Low and behold, I could now boost it with out audible knocking and pinging. What I do see though is that cyl #3 will show signes of knock retard and then another cyl will follow if not all of them. But #3 holds onto the knock retard the longest after starting the trend so.......Who thinks that possibly the balance shafts have something to do with it? Let me know your thoughts. This was a none issue before I tried the boostane 4 tanks ago.

i have a 2.0 and run e85 with stock plugs, #3 is more knock prone than the other cylinders for whatever reason. 93 oct barely helps at all. ethanol is where you can really start adding boost/timing, I hit about 24 ish lb's of boost and 23-25 degrees of timing at wot and no kr. stock my timing was like 0-1 degrees adv. 93 oct I could bump up to maybe 3-5 without any extra boost.