Knocking on firewall ? Or near passenger side

[tom_kauf]

I was about to suggest a Dash Rattle, but is less likely because you say it happens even when at standstill. Most cars have it while going over bumpy roads. But maybe your engine vibrations etc are causing enough movement to make the very common Gen4 Dash Rattle appear.

It's a simple test to confirm it, press down somewhere on the LH side of the dash, and it usually stops. We sell inexpensive Dash Rattle stoppers to fix that issue, if you find out that's where it is coming from.

[AAA]

Hey man, it works for me? It is an m4a file that was recorded with my phone, maybe that's why it doesn't work for your software?

Regarding the dash, I don't think it comes from the dash, it sounds more like a rotating mass/belt/exhaust chug

[tom_kauf]

I can open the file ok. On my Windows XP PC, it plays with RealPlayer.

Definitely not a dash rattle. Sounds weird, different to any suspension knock or CV shaft clunk or Centre Diff noise I've ever heard....

[THE SpecB]

Got it

That sounds familiar !!

[THE SpecB]

Hey man, it works for me? It is an m4a file that was recorded with my phone, maybe that's why it doesn't work for your software?

Regarding the dash, I don't think it comes from the dash, it sounds more like a rotating mass/belt/exhaust chug

Cola is yours consistent ?

[bigBADbenny]

Little Sam, my local mechanic with decades of experience, showed me a cool trick that fixed noisy accessory belts on the President.
Just hold a medium fine file flat on the angled edge of the belts for a few seconds as the engine idles.
Over time the belts build up shiny patches on the edges and the file helps to alleviate the associated noise.
Or just put new accessory belts on, especially if there're starting to crack with age.
I have files if you want to try it.

[AAA]

My noise is inconsistent. I tuned my car and Matt had a look and thought it was either the AC belt or the secondary air pump for omissions.

I have gotten over it now

[muzza]

I have the same sound on my gen 5 auto wagon. Drives me nuts. I have uploaded a sound clip. You can hear that çhugging noise that comes on and off between 500-1200 revs when the engine is hot. You can hear it at stand still if you slightly turn the wheel and the revs go up a bit.

I asked Subaru and they don't know what I'm talking about.

I also heard the exact same sound on another members gen 5 wagon (but manual). So it seems like a design fail. http://www17.zippyshare.com/v/e802L5v0/file.html

Please let me know if you find out what it is so I can cut it out with an axe...

Yes, I have found something similar on mine BUT only when fairly hot - like when idling on hot days with AC running or having just driven up a steep hill when fully loaded - most noticeable when the idle load alters when the compressor cuts in.

I thought exhaust rattle initially

Cant hear it under the bonnet and it comes and goes.

I asked Subaru last service and they thought fuel lines/dampers too, so I pushed the lines around a little and they definitely pulse a bit.

Wondering whether to pack some extra foam rubber in/around them to adjust their tension a little and remove some free play where they sit near the firewall and toward the fuel dampers.

[jiggabite]

I think I know what it is, I get the same tapping and gurgling noise from behind the dash as well. I investigated while replacing the pollen filter and turns out to be a ghost mechanism in the AC system behind the stereo. It happens with the AC/fans on and off while in accessory mode.

The circled mechanism moves by itself and makes the noise. Had to remove the pocket in the right of the glovebox to see it. If anyone knows how to fix it that'd be great.

[bigBADbenny]

Can't see your attachment but Google liberty or legacy HVAC door actuators.
You'll find my post about it. Aka HVAC door murmur/noise.

There's 2 different issues resolved by:
removing the actuator motor and cleaning or slightly bending the contacts on the internal tracks, eg the HVAC door can't self calibrate as the track is worn...
Or
Putting the doors follower tab back in the slot in the actuator cam...

It's a job I'd regard as medium difficult so if your local I can help out