Weird chatter
 

Ive searched but cant seem to find out (or know weather or not) what my issue is. When driving at about 40mph, if the throttle is pushed in about 1/4 of the way I hear a chatter sound. At first I thought it was something loose in my passenger side door so I had a friend drive my car with me in the passenger seat and found out its coming from what I believe is the front of the tranny! It is not rpm specific, it is throttle and speed specific. Ill check again but I believe it happens when the throttle is 1/4 of the way in from 40-60 mph. If I push the throttle in more or let it out, it goes away. If I am going 60+ it goes away and if I am under 40 I believe it goes away.

I am not sure if it is gear specific or not. What the heck is this noise? Since this is my first manual car, I dont know what this noise could be. I figure it could be clutch chatter (though it does not make sense to me), or its just another damn thing that is loose in my car.

BTW I drive a 88 S4 n/a

I had a rattle that I was trying to chase down last summer with similar characteristics. I discovered that it was the spare tire, and the steel rim would vibrate against the body whenever my exhaust would reach a certain frequency. The solution was to tighten the wing nut that held it down. Your problem sort of sounds like a loose heat shield that covers the cat.

could be your driveline is getting worn out, and/or trany mount is bad,
do you hear it if u push on the gas and let off really fast, like tap it while moving?

Or something as simple as a harmonic vibrating heat shield.

Can you get it to happen in neutral?

It only happens when the pedal is pushed in about a 4th of the way down. Actually I was doing some 'spirited driving' yesterday (gotta excersize those 5th and 6th ports ya know) and the chattering noise stuck with it all the way up to 6k. I dont notice anything weird performance wise-- rpms go up with speed like they should, no weird shakes or anything aside from the chattering noise.

I suppose these things could help diagnose:

*It does not happen in netural at all
*It wont happen if I tap while moving
*It does not happen while coasting
*I havent checked the heat shield yet, but it does look like its been cut down the middle (Midas muffler fucked up my entire exhaust putting a damn cat on).

I have a problem that sounds almost like this... But i would say that that this chattering sound comes for me only in 3rd (starts from 2K rpm and finishes at apr 2.8K) and in 4th (starts from ~1.9K rpm and finishes at ~2.6K) gears... And only appears if i'm accelerating... the harder i'm accelerate the more chatter heard... and no chatter while coasting... no chatter in 2nd or 5th... nothing in neutral...

Do you really think it could be a heatshield?

http://www.mazdatrix.com/g2.htm

Sound like any of these? Particularly the bottom half symptoms.

I've read all of that before... No, symptoms are quite different... They are rpm-dependant and not only gear-dependent and acceleration dependant...

I too have the same issue. I want to believe that its the tranny itself.. only happens in 4th gear, and only under light acceleration.. sounds kinda raspy/rattles.. I thought it was the shifter at first, but then it would happen in any gear at the same rpm range.. just the other day i think it started doing that in 3rd gear too.. just a little. first-second, and fifth gears are completly silent... -I just pray that it isnt the tranny.. i just had it installed @ corksport not too long ago.. (and my car is an '86 s4 gxl or something like that)

Well... your problem sounds exactly like mine! If you will come across a reason please post it in this thread!

Mine has a similar situation (S4 N/A w/T2 Drivetrain). It's always had it since I got the car. It seems to only "chatter" at low RPM's in higher gears. I've been Auto-Xing the car for over a year and a half now, but the trans still works fine. (?????)

mabey it has something to do w/ the T2 tranny+drivetrain mated with the non turbo motor? (thats also my setup)

My drivetrain is bonestock n/a... So it's not the reason...

Since we're all talking about drive-line noises and whatnot...anyone care to help me diagnose this? Car is S4 N/A, stock N/A drivetrain.

When at WOT, usually in first or second, if I completely let off the throttle after WOT, there is like a jump in the car, it lurches forward a little, then the engine slows itself down. ALSO there is a "clink clunk" type of noise. Never happens any other time, unless i'm decelerating after going WOT in a lower gear.

I'm guessing it's the power from the motor coming to an abrupt halt and shifting the tranny or driveline a little. I plan on checking tranny mounts, but any other input would be great.

Sorry to hijack...

James

look i have the EXACT same issue im trying to get a new tranny flywheel and throughout bearing(my clutch is pretty good id say) and im hoping that will take care of it....but i know exactly what u mean and now when i release the clutch pedal in first gear i hear a rubbing noise i belive its the throughout bearing althought it was replaced with the mazdaspeed clutch and pressure plate.....

I doubt its the throwout bearing... I have a new one and a new clutch, and it started this the first hour after driving the car.. (I should say, that I first noticed it an hour after enjoying a good clutch and tranny. -and I wasnt driving hard either).
I first thought it was the shifter, as the rattling sounds like its comming from below the shifter..

is ur shifter sloppy as hell mines sloppier than a ganbanged whore...if urs is too maybe our trannies are just grabage? i pretty much know mine is....i heard on the mazdatricks site that the finalgear could be making that sound i was like OHNOES!

my shifter is really sloppy for everything accept going into 5th gear.. I was told that replacing the bushings on the shifter fixes the looseness.. I wonder if that'd be the solution to that odd rattle...?

I was thinking that it could be the driveshaft- perhaps theres a loose bolt, or something?

It is definitely not a throwout bearing problem... i've had a bad throwout bearing and it's different...

Theoretically, since we can't locate the problem - it could be the driveshaft's U-joints... I have a loosy rear U-joint, i will replace both in a nearest 2 or 3 weeks and than will see - will the problem be gone or not...

OT: considerly loosy shifter - i've replaced all shifter bushings and boots and now it feels almost like new! it easily and precisely goes into any gear, like it should...

Thats good! I too would like to replace the shifter bushings, but as of late I'm having trouble deciding if I would like to keep the car. -Theres so many little things about it that need attention...

As far as the driveshaft and u-jounts go, I'm fairly confident that Corksport installed one that was in good condition (or at least passed a visual inspection..), so I have my doubts if its the u-joints.

-Does anyone know how to fix this annoying rattle??? Seems like many of us have it, and seems like no one has a solution. :sadwavey:

When I took out my tranny to replace my clutch, I found two heatshields to be loose along with a bolt floating around on top of one. Though it still is not all back together yet (replaced the pilot bearing only to trash it when trying to put the tranny back in), im assuming this was the problem. So get under there with a ratchet and tighten some bolts! Especially check the heat shield where the exhaust meets the engine.

Please post the results when you'll install the clutch - curious will it cure the problem...

The more and more I hear this, I fear that its a bearing thats starting to fail. Its now happening on my thrid gear as well... ::(:

Welcome to the club :) I have this in 3rd for a long time...