Theres a pretty loud knock or thud noise that I sometimes hear after reversing. The noise happens as the car comes to a stop, it 'sounds' like its more likely coming from the rear than the front.

Also, I have noticed that I can hear a squealing coming from the speakers when the boost is building up. The more I put my foot down, the higher frequency the squealing gets.


Any ideas?

clunk is probably a the rear brake pads.

squeel is probably wind whistling past the wing mirrors.

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Long live the WRC

Could be the brakes - They have about 5000km's left on them.

If the squealing is in fact resonating from your speakers it would suggest a bad earth somewhere. The greater the revs the higher the hertz therefore a higher pitch sound. Then again like tuna said it could be wind, GC's don't seal up so good so at higher speed they do tend to leak air through all manner of door seals, if that's the case the air pressure in your door void might be escaping into the cabin via the speaker holes.

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Omnia dicta fortiora si dicta Latina.

As for the speakers, i may have the same issue in my daily mazda 3 after getting some tweeters installed many years ago. The tweeters would make a whistling/ whining noise as i accelerate, i spoke to someone about it they said it was picking up "engine noise"? never actually got it fixed..but assume the audio install in my car wasn't done properly..

Im thinking the speaker noise is something with the installation - My setup is a big alpine custom job, with tweeters also (which currently dont work).

It cant be a battery issue, my Turbo Timer says the Voltage is 14+, I think the Bad Earth may be spot on. Theres so much electronics in there, I'd have to get an auto sparky to check it out I think.

also if your power wire is run close to your RCA cable it will do the same.

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00 forester GT. 90 rodeo turbo dualcab