Part Throttle Knock

v8hgt · Oct 22, 2017

ManBearPig said:
I took off my catch can and engine cover. Nada. Found one of the motor mount bolts slightly loose and got excited thinking for sure I had found it. Tightened it up and still no difference. Banging around on the exhaust I do notice some resonance that sounds like it's coming from the mufflers. I've read that others have had problems with the MBRP mufflers coming part internally do I pulled the whole catback off and ran down the street on open headers with my off-road leads. Talk about loud. It only took me a mile to determine that was still no better so I went back home. I'm out of ideas.

Email Shaun at AED.
We couldn’t diagnose the source of the false knock on my car then Shaun started seeing it on a few cars on the dyno when none of the usual suspect areas for knock were causing it. The knock sensors are super sensitive and upping torque seems to set them off on some cars. Shaun has turned the gain down very slightly on mine and it’s not knocked since.

ManBearPig · Oct 22, 2017

I don't have Shaun's tunes, and I can't see him being very willing to help his competition's customer much. I also hate to turn down their sensitivity because that's really not the "right" thing to do. But I'm running out of options.

highvoltage · Nov 13, 2017

I was told by my tuner my logs are good. I looked them over and I see some positive knock getting up to maybe 5 sometimes but it jumps quickly from say slight - to +1 and then up to +3 and then goes back to 0. The time says it happens within around 1-1.5 seconds. Its not sustained clearly if only for that short time. My guess its false due to the very short nature. Also it was cold when I did these and I have AS tires. I know my roads aren't the smoothest either. It appears false knock happens a lot with these Mustangs.

highvoltage · Nov 13, 2017

I did look at your logs too ManBearPig and yours seams to last for 1 sec too. Ive had actual knock on a truck before and it was more sustained numbers. I think your good man.

ManBearPig · Nov 13, 2017

Do you have those logs that you could post here for reference?

highvoltage · Nov 13, 2017

I’ll have to do it tonight

Kong76 · Nov 14, 2017

Did I read that right that an exhaust leak could cause false knock? Ive got a leak on my passenger side where the clamp is going into my axleback. Shop over tightened and busted the ears. Puttering noise. Been trying to figure out why the car is down on power.

Part Throttle Knock

v8hgt

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ManBearPig

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highvoltage

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highvoltage

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ManBearPig

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highvoltage

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Kong76

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