High pitched rear noise.
 

Hello. I've got a 2005 Impreza which over the last few weeks has developed an intermittent high pitched metallic sound. Somewhere between not quite a squeal and a sort of jingling noise. Its only when in motion and above c. 40 MPH. Suspect the diff - but could be a bearing - although I've had several go in the past with a low drone - or grit in something ?

Just wondering if anyone else had had similar.

TIA.

David.

Most obvious one for me is a wheel bearing. I've had a couple go and one was a low whirr, the other a high whine almost like a transmission problem.

Is the sound worse with the windows open or in a tunnel? Does it vary between gears? Is it worse at speed? Have you tried rolling the car at speed out of gear?

Check the tyres for pressure as running one lower (e.g. with a slow puncture) can cause the diff to make odd sounds, but it doesn't sound like that to me.

Richard :)

Thanks. Its happening less now but did catch it the other day & opened the window & had a listen, seems to be driver side rear, and was with wheel rotation when coasting - so now suspect bearing.

Will give the rear a jet wash and see if there's grit somewhere too.

Have a check of the rear pads and also check the wear tab is in the correct position.

Thanks all. Well the sound like a metal chaffinch stuck somewhere has mostly gone, but now getting a grinding noise from rear passenger side on left lock. So going to get diff & oil checked pronto.

Well. In the end - it was what the garage have called 'anti rattle shims' (or clips) on the rear brake pads. Bearings & diff are fine (touching wood). :-)