Most Peculiar Noise

[Donie]

In the last few days I've noticed a very peculiar noise in my MYO2 3.2S Manual Boxster.

Initially I though it was a sort of alternator 'unsupressed break-through' coming through on the radio, like you might hear if you weren't properly tuned to a station, but it can't be heard with the radio or CD playing.

It also sounds like the hiss you might hear from a small roller bearing at high speed and appears to be coming from the area around the instrument cluster.

It arrives as the revs drop below 2000rpm in any gear, and may well be there above that but perhaps the frequency is too high to hear it easily.

Is there any taut cable coming from the engine bay that could acoustically carry a sound like this?

It is definitely a 'head-scratcher'.

[Donie]

In the last few days I've noticed a very peculiar noise in my MYO2 3.2S Manual Boxster.

Initially I though it was a sort of alternator 'unsupressed break-through' coming through on the radio, like you might hear if you weren't properly tuned to a station, but it can't be heard with the radio or CD playing.

If I power-up the PCM 1 unit and leave the volume down I don't hear it, but if I switch off the head unit the sound will appear at some stage.

I'm now convinced that it's 'static or unsuppressed break-through' (for want of a better tech description) coming through the amplifier and speakers.

Can anyone confirm that the amplifier (mounted on the bulkhead wall above the spare wheel) stays powered-up even when the head unit is switched off?

Edited May 4, 2006 by Donie