Odd noise on deceleration

[Dipstik-sportech]

Ever since I put the rear subframe and diff bushings in my cat I've been getting a metallic rattle on decel. It only happens that I can hear in 5th gear above 35mph. Sounds like the exhaust vibrating but its been checked numerous times and that's not the issue. Today I had an idea and removed the front two diff inserts and the noise significantly lessened. Do these cars have noisy diffs or could mine be on its way out? I'll try to post a vid of the noise later today.

[apexaddict]

You sort of answered your own question - it's the diff bushings. They add a LOT of noise for not a whole lot of benefit. If you take the rear bushings out, it should go back to "normal".

I did not notice an increase in noise with the subframe bushings.

[Dipstik-sportech]

I've never known a differential to be this noisy though. I'm wondering if it was making noise before I swapped bushings but I just couldn't hear it

[Pure Automotive]

My FX400 clutch makes that horrendous noise when decelerating

[Dipstik-sportech]

Mine is so weird because it only does it in 5th gear which made me think transmission. I swapped the diff and tranny fluids (they were both clean) and still the noise persists. I too have an fx400 I wonder if this is just part of the territory.

[Argento_FR-S]

I recently installed the STi motor and trans mounts, and the rear diff inserts from whiteline. I have noticed a metallic rattling noise as well that sounds like a nut or bolt just barely being loose. The rattling sound is most noticeable in 4th but around 30-40mph. I can hear a separate whining sound from the diff which is what I expected. I also have the FX400 which was quite loud on decel before the mounts etc, but this seems different.

I have a few thousand miles on the FX400, and about 300 miles on the mounts and inserts. The noise just recently started being noticeable.

[Hawk77FT]

Originally Posted by Argento_FR-S

I recently installed the STi motor and trans mounts, and the rear diff inserts from whiteline. I have noticed a metallic rattling noise as well that sounds like a nut or bolt just barely being loose. The rattling sound is most noticeable in 4th but around 30-40mph. I can hear a separate whining sound from the diff which is what I expected. I also have the FX400 which was quite loud on decel before the mounts etc, but this seems different.

I have a few thousand miles on the FX400, and about 300 miles on the mounts and inserts. The noise just recently started being noticeable.

Any news on this mate? I have the whiteline KTD 925 bushing and it sounds like something is about to get loose on the right hand side.

[Argento_FR-S]

The sound continued to get worse. I have found that it was the sound generator tube hitting on the intake manifold. I'm looking to remove the sound tube. Since the manufacturer thought it would be a good idea to use rubber bushings that seem to have shrank and are now allowing a lot of movement in the mounting point.