I've been getting phantom knock in the 2800-3500 rpm range, and can't identify where it's coming from.

Please help me out and list the possible causes for this phantom knock.

- Clutch Chatter
- Tranny Noise
- Down Pipe hitting underbrace
- Lifters going bad
- etc

Thanks,

 

If your running a exedy twin or tripple the noise from the clutch will def aid in that.... What downpipe you running? You should not be hitting the underbrace unless its ebay junk...

 

another suggestion i would get rid of the underbraces and look for another companies, mitsubishi uses cheap *** metal and they flex, if i can get a pic later for you to see at the end of my bars if you look straight down they are bent at the end severly

 

I have an ACT Clutch that's getting kinda old, and the downpipe is not hitting my underbrace, my lifters are a little louder than stock with my Cosi M2's but nothing excessive. I am getting a small ticking noise from my tranny area and my power steering pump has been making noise on and off, beyond that I can't figure out whats causing the false knock...

Underbrace bar is the Cusco 4pt, I've removed it completely and it still gave me this phantom knock, put it back on yesterday after I discovered it wasn't the cause.

 

hmmm... evo usually has a tick at idle.. ACT i believe is not aggresive of a clutch enough to make daily noise, the trans should be fine unless your TOB is bad, stupid question but did you check your fluid or change it in your power steering pump? If your not actually getting harmful knock i would not worry about it... Not worth beating your brains over

 

The ACT Clutch is getting old and chatters when I'm just coasting on the road without the gas pedal engaged. The Tranny fluid was just replaced about two weeks ago. And yes I checked the power steering fluid. The pulley is going bad and making a squeeling noise. I just hit it with WD40 and it goes away for a few days. Still scratching my head on this one.

 

I have phantom knock like you do to but my tob is bad i can hear it rattle and i think thats whats wrong with mine. Does your tob rattle?

 

Ehhh like i said as long as its not hurting your motor and its just "phatom knock" i would not worry about it.. i had phatom knock as well alot with my old set up, its when it gets high in the count i would worry

 

Not sure if my TOB rattles or not, I've noticed a small ticking noise in my tranny so that might be it. I'm thinkin of replacing the clutch sometime soon, but it still holds power great, how easy would it be to just replace the TOB?

 

It does get high, we were pegging the knock sensor at 36 in this rpm range... I made myself some det cans to verify if it was indeed false knock and after listening to the engine I didn't get one pre-detonation sound. As a result we turned down the knock sensor sensitivity and am still recording roughly 15 counts every once in a while. Reason I want this fixed is that it pulls timing and kills performance.

 

Its easy, but do not do it till the clutch needs to be replaced(two birds with one stone).. It prollay is the TOB causing your problem now i think about it... It will prollay hold up for you but i would take it easy till you can dump the money into a new clutch... I hope i was some what of help to you, i have to jet now i have alot of work to do on my car today to get it ready to tune it tonight.... Good Luck

 

Cool, thanks for the info. Yeah I don't want to replace the clutch cause it's holding just fine, but I might have to...

 

Where the hell is my phantom knock coming from?

 

Push your clutch in if the rattle goes away then you know its the tob. When you release the clutch you would hear it rattle again! Im only gettin about 4 counts of knock but like you said it pulls timing and your losing power. When i dont knock i can tell car seems alot faster to me!

 

Thanks for the advice T-revzr I'll check that out. Exactly my point on the power loss though. All the pulled timing makes it run like crap.