Odd deceleration noise from anything above 80km/h! CPV35 6MT

[nicholascleef]

Hi all,

Got a bit of an issue with my V35 manual coupe.
Wondering if anyone has any ideas what could be causing the sound in attached video?
 

• Happens when decelerating from anything over 80km/h
• Steering wheel will shake sometimes, other times it doesn't.
• The noise is present without braking
• Wheels and tyres are fine - IMPUL F919S with new Federal 595RSRs
• Noise appears to be coming from drivers front wheel area
• Calipers are not stuck

I've put the car up in the air and can't find anything visually wrong underneath. Spun the wheels by hand, sounds normal.
Was hoping it would be a wheel bearing, but now I'm not so sure.

Any ideas?

 

received_1749827491756552.mp4

Edited December 13, 2017 by nicholascleef

[sonicii]

have you checked for loose plastic inner guard covers, sounds like something slapping around in there, maybe some of the plastic clips have broken?

Other than that, possibly bad bushes.  Does the noise go away if you apply brakes?

[nicholascleef]

The noise doesn't go away if I apply brakes, nor if I put the clutch in. Inner guards etc are all secure and as normal. The noise only goes away once the vehicle has slowed down to below 80km/h regardless of whether I apply the brakes or just let the car gradually slow down.

Has brand new rotors and pads. Clutch is brand new too - Exedy heavy duty, single mass flywheel conversion.
Front lower arm bushes and lower ball joints replaced also. All this work was done less than 5,000km ago, car has been driving fine until recently.

Noise started occurring when I was giving it the beans, so I've obviously damaged something.

Edited December 14, 2017 by nicholascleef

[ka86]

I know you said the guards are secure but plus one on sounding like loose plastic.

I had an issue awhile ago where one of the smaller plastic covers that links to the undertray was loose.

Wind would hit it at certain speed, get partially trapped and would make noise.

 

[sonicii]

hmm.. if it was bushes, I would expected to have seen some change with brakes, possibly steering linkages, but I would think that would be more obvious.

I know you checked, but the only thing I can think of that lines up with the symptoms well is a loose splash guard or fender liner.

Giving it a boot full of throttle shouldn't have broken anything in the front suspension, it is just there to steer and brake.

[nicholascleef]

Thanks everyone for the responses. The noise ended up being the under tray, some of the clips were broken, hence it was partially loose. Not sure how I didn't notice this the first time I had the car up on the hoist. Obviously it was catching the wind at 80km/h+.

[sonicii]

Nice work.. good to hear it was nothing serious!