Whistle at idle - vacuum leak, induction side

[RichieRoo]

Ok, as promised, here's an update:

Today I tried spraying some WD40 around the parts which could be leaking air,
the whistle was constant so we decided to strip the inlet side.

Took the throttle body off, all the pipes and the inlet manifold. Visually it all
looked perfect. All the rubber seals looked like new.

I applied some gasket sealant to the manifold gasket before reassembly,
just for good measure.




The throttle body and butterfly were both pretty clean, but I went over them
with carb cleaner and the came up shiny.

Reassembled it all... Whistle still there and engine still rough on idle.
See video here.

Initially, from cold the car runs fine, but then as it warms up an the revs gently
fall to a normal/warm setting the car begins to whistle, clatters a little and idle
poorly (as seen in the video).

So I'm now stumped. Any ideas?