Deep rumble when coasting in gear

hey all. Taking my 2006 Legacy GT Spec B in for service, just wondering what you all think about this. I get a rumble noise when Im coasting, in gear. Any gear but its louder in lower gears at higher RPM like the 2500-3500 range. The higher RPM the louder the rumble but ONLY when I am coasting in gear with foot off the peddle, as soon as I hit the peddle it goes away, or if I slow down belows 2000 RPM. Im sure its still there but I just cant hear it. Does this ring a bell for anyone about what it could be? Hard to describe the sound but to me it sounds like what an 18 wheeler sounds like when it down shifts. I think its comming from the driver side front left but Im not positive. Thanks!

Check the exhaust system, it may be a suspension that's bad or that it's improperly mounted and pushes against the body of the car.

 

It may of course be a bearing too, hard to tell without hearing the sound.

Thing that throws me for a loop is that its only when Im coasting in gear. Coasting in neutral is just fine. Does that make sense?

Do you hear it right after a down shift? Like you make it into gear, the engine hesitates for a second, then you feel it kick in and start making the noise?

No. I could upshift to 3rd gear, give it some gas to get to over 2500 RPM or so, let go of the gas and just coast and then I can hear it. or I could downshift, let off the gas and I hear it. Only when I am coasting. Everything feels fine. It shifts fine. Power is fine. Other than this strange sound, I would never think anything was wrong with my baby.

I have experienced a very similar symptom with my legacy...only difference is that I could only really notice this when I am in first or second, and usually only when I am high up in Revs...Keep us updated!

Living Legacy... did you ever get it checked out or did it go away? Was it imtermitent? I can make that noise happen whenever I want. And like you, it is most noticible in 1st, 2nd gear at higher RPM but in higher gears I think its still making a noise, just not so loud.

Pretty sure this is normal in the 6 Speed. I have this noise too, mostly in 1st or 2nd when i coast in gear around 3000rpm down to 2000.

Do some searching as i believe it was discussed a few times before. I think i may have started a thread on it too.

It was intermitent. I mentioned it to Subaru (of course they found nothing), and it did end up going away.

 

I never noticed it below 2K and only noticed it in 1st and 2nd. The noise was deffinetly from the front end, but I didn't notice a bias towards one side or the other.

I have the 2006 Spec-B. It has a 5 speed. I have had the car for 2 years and never heard such a sound. I realize that higher RPMs make louder engine noises but this is a deep rumbling (something is shaking loose) kind of noise.

I took it in and they said it was the Flywheel. They are ordering it and it is covered under the warranty so we shall see...

Hey all... can a bad flywheel do any other damage to my car? Thanks

Just to post the final update, got my car back after a week and a half! New flywheel, under warranty still so no cost to me and the sound is gone! Can anyone explain why a flywheel would make such a noise when coasting in gear?

Slightly unbalanced flywheel can cause that. Not good for the bearings in the long run but since it was only noticeable when coasting it had to be a minor case.

 

But keep any receipts/data from that just in case there is a later issue.

Yeshia, I had that exact same problem, but I would not have guessed it to be a flywheel. My sound did go away the very day I wanted to take it in to the dealer. Figures, right?! Anyway, to me it sounded like an exhaust leak created by the engine braking, but I couldn't narrow it down before it went away. And it only happened when the car was cold, but once it was up to temp for about 20 minutes, it went away. Very strange.

 

Dave

Mine sounded more like exhaust to me as well.. but then again most grandmothers know more about cars than I do.

 

It did it hot or cold however.

mine does this only in 5th gear at about 70-80mph if i coast and let off gas i get a slight resonance in the exhuast but im pretty sure its just the backpressure.