My cars developed a 'hiss' which sounds like its coming from underneath the gear lever - so presumably from the gearbox. Its more apparent in 4th and 5th and the pitch goes up with engine speed, however if I back off the throttle completely it goes away. There is still a faint hiss while the clutch is disengaged, but nothing like as loud as it is in-gear. In neutral - no hissing at all, but I can get the hiss to happen if I push the gearstick either left or right from the neutral position with a little more force than I would usually.

Gear selection is fine (the usual stiffness when cold but fine when warm) and the gears never pop out, clutch can be a bit juddery at low RPMs but no more than (I've read) is expected with Imprezas. There's a faint whine in the gears from the gearbox, but nothing alarming or out of the ordinary - the hiss is something else on top of the usual noises I think.

I'm going to take it to a local specialist for him to have a look, but I'm curious as to what it might be and would like to go and see him armed with some suggestions - I've next to no understanding of gearboxes so don't really know where to start! The cars a 2001 Bugeye WRX, on standard (as far as I know) clutch and flywheel.

 

local specialist says its the turbo and TD04s are notorious for being a bit noisy... newbie mistake!

 

i have a the same issue :s on my05 sti, exactly the same syptoms but i would say its more of a little whistle type noise??

 

snakes.

 

 

as trails said, S N A K E........ could try a gearbox additive??? saw dust ive heard is used by garages that sell cars. lol well thats what i hear.

 

This sounds like the same problem I am having on my 2002 WRX see
https://www.scoobynet.com/drivetrain...box-noise.html

I am looking for someone local (north east) to sort it...

 

Alyn at AS Performance. Drew or lad called fin all local and highly recommended. Join tts or nesf for contact details. :-)

 

To be fair I haven't checked for snakes...

The guy I use is also on the NESF forum, Andy Kindon based in Chester-le-street. He said a whine would indicate diff/gearbox issues but that its a very obvious whine rather than the hiss I'm hearing, which he's sure is just the turbo being a bit loud which is typical with these - I'm just not used to being able to hear things like that!

 

Can always try one the others I mentioned for a second opinion. Av seen his name before and always with good comments. I no what you mean though. When you hear a noise it is unsettling

 

Yeah, I know what you mean about the hissing sound, but this sounds more like a bearing and the noise will "bounce" on and off with the accelerator, the way a diff sounds. That's why I'm not sure its the turbo...?