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?

[GeneW]

Originally Posted by RichieRoo

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?

You have a Scanguage? Set one of the displays to engine temps (I believe it's FWt). There is also an "Open" and "closed" display, don't recall offhand where they might be.

See when the motor's idle changes.... I suspect that the motor is adjusting for a leaner mixture in closed loop and that you have "lean idle lope".

As for the sound, that could be from different places... you are sure that you cannot hear it over the "cold" idle?

Gene

[bronsin]

Originally Posted by 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?

My Suzuki DL1000 Vstrom whistled like a tea kettle once. It was the fuel pump straining against a semi blocked fuel filter.