okay... so for the past week ive been trying to find this nasty rattling grinding sound from under the passender side. the sound is very intermitent, it only happens when the car is very warmed up, some times it just doesnt do it.



when it does happen:

-starts at 3k and up under heavy braking
-continues when going below 3k after it ocurrs
-braking and building up boost
-accelerating up a steep hill
-accelerating on a turn, i.e. taking a right turn or somthing
-always has to be when the car is rolling
-engine braking
-any gear as long as the rpms are up



it does not happen:

-clutch depressed and revving
-clutch depressed and rolling
-clutch depressed under heavy braking



things that trigger it:

-accelerating up a steep hill
-long periods of driving
-very hot days
-when building high boost



things i have checked/ fixed:

-boost leaks, ive have removed and replaced the entire exhaust system twice in the last two days, this includes the exhaust manifold, up pipe, down pipe. all gaskets have been changed to brand new oem units.
-up pipe heat shield had broken welds and was very loose, i welded that back together
-down pipe to transmission braket was broken, i welded that back together
-inspected for leaks, no leaks have been found except both left and right steering rack boots...(been meaning to fix it but i would need a new alignment)
-inspected for any loose suspension components



last options i can think of:

-drain the tranny fluid and check for metal debris, i suspect that the probem maybe a blown center diff



most recent mod:

-gruppe-s header



current mods:

-hks hipermax rs coilovers
-invidia V2 downpipe
-cusco front strut bar
-cusco rear strut bar with v-brace
-generic H-brace
-perrin heavy duty rear swaybar stout mounts with stock sway bar
-gruppe-s header
-trust dd cat back




those are all i can remember at the moment. if it is my center diff, has anyone had any experience fixing it? like always, i want to avoid taking the car to the dealership... ive only done so once, and it wasnt exactly fun, they didnt fix anything and voided my waranty, that was pflueger at the time


oh... heres a video, you may have to turn up the volume. the sound you hear that may sound like the wind is actually the sound im tryin to fix. i have the windows rolled up!!!


http://www.youtube.com/watch?v=Ukv55vJBMTc


thanks for any help and input you guys can come up with!!

 

what do you guys think?

http://forums.nasioc.com/forums/show...ti+center+diff

http://forums.nasioc.com/forums/show...ght=half+shaft

 

wow it might be your center diff or possibly a bad driveshaft bearings. Never looked at the two links posted above yet.

where is your center diff set to at the moment?

 

yea suckage... do you mean the dccd controller? its on auto, i never play with that.. i didnt take the time to learn about it so i never touch it to avoid breaking anything lol... i did notice that some really steep driveways would cause my front end to clank very badly. i guess things are getting worst now. its probably due to my drop, but the car is not even that low...

 

Wow I hope to hell it isn't your tranny or diff.

But that's probably what it is. Perhaps one of the various thingies that touches the tranny like the mounts and such?

 

Other than the clanking noise, your ride sounds awesome!

 

^^lol thanks...


yea, ive been underneath how many times tightening that looks like it could have gotten loose... i wish it was just something loose.



im gonna go ahead and change all my fluids tonight.

 

could be some spare change clangin' on some metal.....that happened to me once....drove me crazy!

 

changed my fluids tonight, suprisingly the fluid looks pretty good... im totally lost now during the test drive, again, the car must be warm for the knocking to occur.....

 

might be your driveshaft bushings. i changed mine out to beatrush ones found on i-club vendor section since mine were completely nothing already also double check your exhaust hangers as they could move more when car is warmed up. doubt this is it but doesn't hurt

Jon

 

hmm interesting, ill check it out those bushings.

thanks

 

I got those too but they are sitting on my room... :RockOn - not mine:

 

I got those too but they are sitting on my room... :RockOn - not mine:

 

yup. my bushings were shot and basically only had a metal sleeve there. changing it out and all is good

 

so i went under and checked the carrier bearing and its good, very flimsy but its good. i wonder if theres a stiffer aftermarket one out there...

today, i pulled off the header and decided to do a simple compression test on the pipes....

the results are in this video:


http://www.youtube.com/watch?v=V9BPBGuBAfs


im gonna go ahead and throw the stocker on and drive around to see if the sound is gone...

thanks for all ur input guys!!!