False knock....where to look?

[TyphoonFiST]

So I am starting this thread about where are some good places for others to look for false knock around the Vehicle instead of dumping e85 to determine if its false or not. We are talking about things vibrating...rubbing...clanking Etc. So feel free to post your findings to help others.

 

[green_henry]

False knock in that you're hearing something or that it's showing up as knock on the AP? When I first bought the car, I had some "knock" noises (particularly when the engine was cold) that were quickly resolved with an upgraded RMM and upgraded exhaust hangers.

 

[TyphoonFiST]

Showing up on the Ap3 with Neg.corrections randomly. I'm going to look over my mounts and intercooler clamps tomorrow afternoon. Went over the Exhaust today....took off my Turbo blanket to look at my turbo..Think I may have found something there but have to really get in there today when I get home from work.

 

[PunkST]

Charge piping rubbing or hitting might cause it.

I get random corrections as well. Last way too big part i still have on is the hot side pipe. Which i know hits the chassis brace.

 

[TyphoonFiST]

I think I have found where my Gen2 contacts the Block on the backside of the engine. this may be a possible source of false knock.

 

[PunkST]

That would do it. Harmonics and all that sending resonance through the block to the knock sensor.

 

[TyphoonFiST]

That's what I'm thinking also....now I just gotta get my Dremel in there and do a little filing. Thought maybe id get lucky and it would be exhaust....took a rubber mallet to it to see if I could get and differentiation in sound as I hit on it moving down to the tips.

 

[PunkST]

These cars have a suoer sensitive knock system too. I wonder how many engines got trashed due to sometbing as simple as bad harmonics.

 

[slopoke]

Other things that may cause it is, worn pulley, water pump, alternator, belt tensioner pulley. Basically any accessory on the R/H side of the motor.

 

[DieselMech]

Exhaust leaks near the Down pipe and cat back will cause this too


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[TyphoonFiST]

Exhaust leaks near the Down pipe and cat back will cause this too


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How so?

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[DieselMech]

How so?

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When my rpm range would hit a certain note it would register the knock sensors like crazy. The last thing I changed was the cat back so sure enough I tightened the will to live out of the flange bolts and all was good. They are essentially mics so it made sense.


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[TyphoonFiST]

When my rpm range would hit a certain note it would register the knock sensors like crazy. The last thing I changed was the cat back so sure enough tighten the will go live out of the flange bolts and all was good. They are essentially mics so it made sense.


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Very interesting...never thought about this

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[TyphoonFiST]

Well I will come forth at 61k My Boomba mount inserts in the urethane have decided to start spinning in the urethane and making a clicking noise/feeling when turned with your fingers. I went from seeing Negative corrections of -3 to as high as -5 to seeing -1 and lower now with the Stock Mount back in place. The Vehicles performance has drastically improved now...its Freakish. its crazy how much that false knock and - corrections can cut into your performance. I hope this helps others...just because something looks fine to the naked eye doesn't mean it is still in working order.

 

[PunkST]

I should check mine, lol. Its got 80k on it.

 

[DieselMech]

Well I will come forth at 61k My Boomba mount inserts in the urethane have decided to start spinning in the urethane and making a clicking noise/feeling when turned with your fingers. I went from seeing Negative corrections of -3 to as high as -5 to seeing -1 and lower now with the Stock Mount back in place. The Vehicles performance has drastically improved now...its Freakish. its crazy how much that false knock and - corrections can cut into your performance. I hope this helps others...just because something looks fine to the naked eye doesn't mean it is still in working order.

It’s a crazy difference for sure but I’m glad you got it sorted


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[TyphoonFiST]

I'd like to get it more calmer than it is now. I'm gonna do some more looking to see if I can find anything else. Im also going to sand down a ear on the block that is Thousandths away from the Turbo.

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[Se7eN]

Well I will come forth at 61k My Boomba mount inserts in the urethane have decided to start spinning in the urethane and making a clicking noise/feeling when turned with your fingers. I went from seeing Negative corrections of -3 to as high as -5 to seeing -1 and lower now with the Stock Mount back in place. The Vehicles performance has drastically improved now...its Freakish. its crazy how much that false knock and - corrections can cut into your performance. I hope this helps others...just because something looks fine to the naked eye doesn't mean it is still in working order.

crazy how something so simple can affect so much

 

[Clint Beastwood]

I get false knock if I accelerate at low rpm while turning left. No problems turning right

A gallon or two every 2-3 fill ups makes most of my negative corrections go away.

 

[Ox_fiestast]

I get -2.5 or so when using launch control and get the odd -1 here and there WOT on miscellaneous cylinders but usually cyl1 and cyl4. Running step colder plugs gapped to 0.28 tuned by tuneplus on x37 turbo

Maybe I will try adding some e85 and see if that helps, dont want to blow it up but im always giving er