wicked white14

Well, this is a weird one: So, I started noticing this a week or so ago......This only happens when I can row through the gears from 1st-4th while getting on the highway on-ramp while at WOT and taking it up to about 6K RPM before shifting.

As i shift at 6K RPM, i push in the clutch and for the couple seconds between shifts I hear a vibration/ sound resonance coming from the back end of the car? However, this only happens some of the time as it is not reproducable on commmand. Am I being ultra paranoid or could there be a problem developing? As stated, I have to be ON WOT for this to happen.........even if I am cruising in 3rd gear and take it to redline I cannot reproduce this noise. Seems to only happen on the on-ramp while going through all of the gears? Sounds like a "tinging" noise and it only happens while I am in between gears and at about 6K RPM? Its not ultra loud, but loud enough that the first couple times it was audible over the radio.
The car is an '08 GSR that has 35,000 miles on it with only a DC Sports catback exhuast. I had a problem a year ago with the flange in the mid-pipe expanding as it hit cold water and it was being pushed into the driveshaft and THAT noise was loud and obvious, this...not so much.................

Does anyone have any ideas, or is this another case of somehting just loose somewhere and a vibration being made as it only happens during shifts at high RPM's???
Thoughts, please??????????????????????????????????

wicked white14

Anyone with ideas??

xTiCkxMYxLaInTx

iTrader: (11)

It only happens on a specific on ramp? Maybe it's the material it's made of or something.

vegittoss15

iTrader: (2)

Can you describe the sound better?

wicked white14

it is not a grinding sound but a "tinging" like a veberation or imagine if you put a marble in a can and oscilated it, like a "whirling" noise...???

wicked white14

mmmm, doubt it as it never used to do it.

vegittoss15

iTrader: (2)

Hmm, I remember a similar sound came from my shifter bushing pins at a higher RPM.

Kracka

iTrader: (49)

You get one thread.

wicked white14

Hey, can anyone with a little more mechanical prowess help me on this?? Now that the weather is getting nicer and I have been driving with the windows down this rattle between high RPM shifts is killing me!!!!! Does anyone have a clue here what could casue a "rattle" between shifts????

Vivid Racing

iTrader: (98)

If it's coming from the rear of the car at high RPM, check the rear diff and driveshaft.

Also, are you really going WOT all the way through 4th gear when getting on the highway? That's over 100 mph...

Topshot

Is there any vibration at idle? When I had my X, I put TS exhaust hangers on my Legamax CBE it would vibrate or produce a knock when I shifted quickly in 1,2, and 3. Checking to see if you replaced anything on your exhaust?

wicked white14

[QUOTE=Vivid Racing;10079671]If it's coming from the rear of the car at high RPM, check the rear diff and driveshaft.

Thanks! I checked everything as I had all of the fluuids changed last year and everyhting in the rear end is clean with no play or movement........I do not think it is coming from the rear end......almost in the middle of the car......I have a DC Sports Exhasut, POS, and the damn thing buzzes sooo bad I wouldnt doubt it is making somehitng rattle............

wicked white14

Hey Topshot, yea the DC Sports exhasut buzzes hella bad at idle so i wouldnt doubt it is some type of rattle due to the sound resonance from the exhaust......would that many any sense?

Topshot

Yeah man, I would take it to an exhaust shop to see if everything is bolted down properly. New hangers may help but in my situation they just made that knock sound as the exhaust system wanted to move between shifts but the hangers made it so stiff it sent the vibrations as knocks felt through the floor. If you have your stock setup still you can put that back on and see if the problem goes away and if it does you may want to get a different exhaust system.

laxplayer14

iTrader: (4)

it may just be your exhaust smacking on the bottom of your car. i had something similar happen when my shift was just slightly off from "perfect"