False knock track down, Help

Austin Brian

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Jun 17, 2021
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Location
Detroit
2014 Mustang GT 6r80
So my setup is very clean. I’m running e85 and the fuel measured decent last I filled up around 75% it’s usually around 80-85% at least but lately it’s been junk.

idk if they has something to do with my timing is being pulled when I’m WOT near redline. Highest it got was +4.00 car feels healthy and fine.


here is a video of my engine bay, I’m thinking my oil catch can is rattling around causing a vibration and that’s what’s giving off the false knock. I sent some logs to my tuner from Lund and he said everything looks okay and it’s false knock. My exhaust system is very well done and nothing is rubbing there I’m positive.

what do you guys think?
 

Riddick

MERICA
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Oct 25, 2012
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Dayton, OH
It's more than likely part of your exhaust, I highly doubt its your catch can. It could be anything from a loose fastener, loose o2 sensor, or a bolt barely rubbing the body. With your engine cold crawl under your car and use your palm or a rubber mallet to hit your exhaust, check at headers, mid pipe, and over axle pipes. There should be 0 noise, if you hear any rattling what so ever there's your issue.

I guarantee its false knock, especially since your on ethanol. On my set up I had an issue with the fasteners kooks sent me. They came with locking retainers for the bolts so they wouldn't back out and they rattled like crazy. Removed them and that fixed my issues. Also, keep in mind your exhaust moves with your engine under load. If any bolts are close to the body there is a good chance they are hitting your body under full load.

Best of luck and make sure to report your findings back to us.
 

Austin Brian

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Location
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I’m running stock headers still, I did a bunch of data logging and secured a bunch of stuff. I think I had some lossy e85 my most recent fill up and logs I’ve done and smoke with my tuner. I only seen 1 little spike of 1 degree timing being pulled and it went back down instantly. My logs look really good the cars loving the fuel it has in it down seeing you to -4 degrees being added, and 30 degree spark advance at WOT, she’s happy I’m happy too. I have my car on my lift at the shop every week and haven’t noticed anything hitting. I’m very thorough with my car, however I’ll double check stuff again. I spent like 2 months dialing in my whole exhaust system recently so it should be good.

Thank you for the advice however, I appreciate it.
 

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