Whistling sort of sound

[Mike]

Hi all,

I've noticed a kind of whistling noise when accelerating in the 1500-2500 rpm range, it's not a really loud noise, but I can hear it when the windows are down. Once past 2500 it seems to disappear. I don't need to be accelerating hard for it happen, is this normal? Could it be a belt or my airbox? I've got a standard airbox with an ITG filter, but it was making the noise before I changed the standard filter over.

Cheers
Mike

[Laine_16v]

Gearbox differential? mine makes a whistling noise at the same revs and will dissapear at higher ones too.

[Coops]

make sure the oil breather from the airbox to the centre of the rocker cover is connected, the big one that runs up the middle of the inlet manifold!

without that connected it whistles!

[jwarren2k2]

ive got that noise too, i just thought it was the induction kit... when the throttle valve is part open (lower revs) it whistles because of the gap between the valve and body?!

duno if thats right, but thats what i thought it was...

[Scott-16v!]

mine used to do that too^ since swapping over to a standard airbox this morning it's stopped

[Coops]

oh if u got a i/k then yeah, thats just a noise open ik's make, eudnt worry! :P

[Mike]

Thanks guys, I checked the oil breather pipe and it seems to be connected up well, could it be the gearbox differential then as you were saying Laine? If it is that, will it need replacing soon?

Cheers
Mike

[rt_blackpool]

i think the question is mike, do you have an induction kit or the standard airbox on the engine?

[gtbloke]

Was gonna say the i/k's whistle like mad

[J o n]

diffs whine, air induction is more of a hissing sound, but mine does the hissing noise.