umm i have a downpipe i dont have the turbo heatsheild either so..and i only get it in 3-5th at like 2k rpm...so if it was a heatsheild rattling ..it shouldnt care wat gear it is anyways? what take do you have it being the final gears in our trannys? the mazdatrix thing makes it a possiblity......

hell new trannies anyone? 300bucks shipped im sure we can find like 4 of em for us? group buy!!!! lMAO! hell id be down

Actually the tranny itself is what the first reason for the noise is coming to mind

Ya- I have a 'new' jdm tranny or something... it could possibly be the shifter itself, or something that connects to it. Also- It happened this morning as I was in neutral, coasting to a stop... it wasnt as bad as if I were in 4th gear, but was definatly noticable. Reving made it stop for some reason. ???

--Any updates???---

I've got a Euro-tranny, but shit is the same :) No updates yet... Looking forward for my broken U-joints to be replaced... May cure this problem as well as shifter vibration when acceleratin', but may not though...

Did you try having someone else driving the car and listening for where the sound came from? I did this and found it was coming from the front area of the tranny where it meets the engine. I popped the hood, grabbed the heat shield, and all it did was wobble. Dont know if you will find the same thing but it might help.

haha, mine JUST started making this same noise as of last thursday.

it starts around 40 mph as you said, isnt really RPM specific. when I let off the gas it stops. other than putting on new tires a few days before this happened, I hadnt messed with anything and it never made any noises.

weird.

Yeah... Really weird!

2 Longshoe: yes, i've asked somebody to listen where are noises coming from and it looks like they're from the same place you've mentioned, but no heatshields are loose so i'm lost with this...

any updates anyone???

I finally put my car back together and ive still got the noise, although its not nearly as loud as it was before. All I think the noise could be is either the exhaust manifold (which wobbles around a little because the fools at Midas cut it down the middle a little bit) heat shield, or something inside the tranny itself (which I think is unlikely since the noise does not sound like its coming from the gearbox). I guess ill find out for sure if its the manifold heat shield when I put headers on in the summer. All I can recommend is tighten stuff down, or just drive it until something breaks lol.

After tinkering around with the car- I found that my exhaust is cracked and is well- junk...

People that have this wierd chatter, do you have a stock exhaust? (or do you get fumes in the car when its on, and parked?) -I hope I'm on to something!

I recently installed a Bonez hi-flow cat, but the catback itself is stock. And old. And lately, sounds a lot crappier.

I don't get any fumes, but like I said, the sound quality has really dropped off over the past two months, so it may somehow be related.

I have a new exhaust arriving today.. RB header, to a borla stainless catback.. gonna evaluate the bonez cat, and a resonator.... hope to have updates soon...

Ok- Finished installing the exhaust and everything. Drove around for a few days to make sure everything was settled in, and as it turns out, the rattle is still there. I replaced the WHOLE exhaust w/ a RB header, Bonez cat, and a Borla catback. Its a bit too burbly for my taste, but the power is definatly there! :)

~The search for the rattle continues...... :(

its not the exhaust.. i have the same problem... make sure u have the right oil level in ur tranny... if its on the right level, it could be a worn syncronizer sleeve.... rattling for sure coming from the tranny... mine, when its low on oil for tranny, it does teh rattles, but when i fill it up it goes away, it just came back recently again so hopefully its just ur oil level, but yeah, mostlikely theres something worn out in ur tranny

Hm, I'll give that a try. As well, I am going to subscribe to this thread. We must find that damn chatter.

I've been having some other strange issues which may or may not be related to the chatter. I'll throw it out and see if anyone with a chatter can relate:

Car pulls fine in first and second gear. Third gear, however, is a bit .. errh... clunky. There's this obnoxious banging if in the upper revs (say, 5000 and above) at WOT. It sounds pretty scary so I just stopped redlining the car through all the gears, which has really made driving the car a lot less fun lately ...

Another issue -- in fourth gear, on the highway, 4000 RPM. NO acceleration whatsoever. No weird noises though, the tach just sits there like "I aint goin nowhere bub!". Shift to fifth and everythings cool again.

Maybe the chatter just means your tranny sucks.

Yeah, it's definitly not the exhaust, 'cause mine is all custom... And i have that chatter... But i've changed my tranny to euro-spec last summer and chatter is still there at the same gears... So i see two posibilities:

1) it's just like an illness of our trannies... my euro-tranny had the same defects as my old a-spec one... i have a third spare euro-spec tranny, so i could check it out some day and swap it in...

2) it's not related to tranny... but than again, i'm lost...

On a side note: I checked my tranny oil levels and the oil was a teal color, like a turquise or something.. I used redline synthetic oil (thanks corksport), but I was thinking it could have been the racing version which is not to be used in most transmissions because it'll eat the syncros (as there made of copper or something, and if I remember correctly, copper oxidizes in that color). Any one else use redline tranny oil? And are my syncros going down the crapper? :(

OK, update from my end of things.

The chatter has now transformed into something much uglier and potentially engine threatening.

Now I'm starting to believe it's the sound of detonation -- I know, I didn't think it was that likely with a (more or less) stock N/A as well. But my car has gotten WORSE to the point where I'm afraid to drive it.

Going up a hill, accelerating on the highway -- hesitates, sputters, chatters. Yet compression is still above 100 PSI. The weird thing is, after 10 minutes or so of really horrible highway driving, it stops hesitating and drives normally (though the chatter still persists).

I don't know why this would be affecting me now (perhaps I somehow advanced the timing back when I last tore it down), but I think everyone experience this noise should consider detonation. Especially if the symptoms start to worsen -- mine started in fourth gear, then third and fifth gears, and now even first and second gear.

Sounds really ugly and scarry... But i'm not at that point yet... And hopefully won't be...