2nd gear deceleration grind-type noise - video
 

2006 wrx sti

Sometimes get a faint grind-type? noise which seems to follow a yo-yo type frequency on deceleration in 2nd gear between around 2000-1700 rpm mainly. i.e. accelerate to just over 2000 rpm and coast in gear with foot off accelerator. Seems only noticeable in 2nd year in this scenario with the right rpm's and on a quieter street. Accelerating of putting the clutch in stops the noise. Interestingly accelerating to 3000 rpm for example and letting it wind down the noise still only starts around 2k.

I've spent quite a bit of time researching this noise on the net and there are loads of posts on various forums describing deceleration noises, and there does seem to be a general complaint in this area with quite a few theories, from flywheel/clutch to just a 'normal' noise.

Drove around a bit with the iphone recording and this is the best example I could get, probably because it was quiet and road enclosed so the sound it more apparent.

I'd be interested to know if anyone has noticed anything similar first hand? thanks

P.S - Turn up the sound, the recording was very quiet generally or some reason!

It does sound like clutch chatter videos I've watched on youtube, also someone posted a video of their 2011 wrx with a similar thing.. https://www.youtube.com/user/mrkyle72

Very feint sound recording, but I think my 07 plate STi Spec D does the same. 34k miles.

I think it's perhaps rear diff or transmissions idling / winding down. Mine seems to do it more after a long / colourful run shall we say.

Always done it, and isn't getting worse or causing any problems for me.
I too get the clutch pedal squeaks, but probably just needs a squirt of WD40 on the pedal assembly somewhere thats all.

Perhaps check your gearbox and rear diff oil levels. Mine were fine, and I'm sure yours will be too.

Recently had my oils changed by the way, and not made any difference. Am I worried, nope.
There are so many things working underneath on an STi, I think it's just normal mechanical winding down sounds to be honest.

What clutch have you got? Unsprung paddle clutches are very noisy, sprung paddle clutches are noisy but not as much.

Yes, sorry.. the sound is rubbish I have had to turn up my sound to MAX on the laptop to hear it well. I think the iphone mount was covering the mic or something!

thanks, I will check the levels though just to be on the safe side, its just been serviced a couple of months ago so I think it will be ok.

Lots of the other information on the net mentions 2nd year too, It does seem to be the most noisy generally!

As far as I know its a standard clutch, but who knows maybe it was changed by the last owner.

Mine is quite stiff to get into 2nd gear until the car has driven a mile or so.

Keep your ears and eyes on it, but I wouldn't worry about it, and yes, I only get this in 2nd gear too.

For me personally, I feel it's just "how they are" Some are maybe noisier than others I suspect.

I'm glad someone has raised this, as now I feel I'm not alone!

I had the same noise on my S202, it had a 4 pad Carbonetics clutch. When you push the clutch down the noise would go away.

Mine does it in 3rd and 4th, with clutch in or out I'm running a excedy pink box, I'm not to worried about it if it goes pop ill change the box

mine does the same, 95 wrx with 98k on it, lightened flywheel and api clutch plate etc, just put it down to wear and tear really LOL

It's very faint I agree. It might just be clutch 'thrash' which is the springs in the friction plate loose and rattling around in their location. A common problem, It could also be a heatshield but it is very hard to tell over the internet. Take the car somewhere they know what they're doing and ask for a road test. Be helpful to know the mileage of the car unless I missed it further back.

David APi.

sorry yes, wasn't in original post. 41k

Bloody heatshields, I have one vibrating at low revs. To be fair I have to keep cutting bits off the heatshield at the very front part of the manifold.
As for noises on decelaration, mine does the same, but now my diff has shed a few teeth its rattly as well! Nothing to worry about, in my opinion the Impreza has quite an agricultural 4wd system and there is nothing to worry about.