05 22v 5.7 MPI rushing air sound.. Circulation pump?

[wnytige]

Hello..
We have a 2005 22V with the 5.7 MPI water sports motor with about 400 hours that is making an odd noise.

It sounds like rushing air and the sound does go away occasionally and gets very quiet.

I have just replaced the serpentine belt, the water pump impeller (and have a long story about all the extra work that went into that) along with the thermostat and an oil/filter change.

The noise was there before the work and is still there.
It's a fairly loud sound but doesn't sound metallic.

It seems to be at the top of the motor near the rear of the boat.

I'm wondering if it could be the engine mounted circulation pump.
The original rubber impeller did disentigrate and two fins were trapped at the oil filter.. but the engine never over heated or ran poorly.

The oil pressure is fine, the temperature stays fine.

However, is seems like the engine RPM's dip for a second when the noise comes and goes.

Any thoughts or knowlege would be greatly appreciated.

Thanks

[boatwakes]

That is the IAC, idle air control valve. Completely normal.

[knochels]

I had that noise on my 2203 22v this spring. My mechanic fixed it by replaceing muffler(I think that what he called it) on the idle air control vavle.

[wnytige]

All..
Thanks for the quick reply.
Now that I have read more about it.
I think I may have an failure coming.
We have noticed that the boat does stumble just off idle.

Seeing as the part is about $100 we may just replace it.
I'd hate to have it fail out on the water and loose a whole weekend because we can't get the part.

Thanks again!!

[wnytige]

Idle Air Contrl Valve Muffler part number?

Thanks again for the info.

Does anyone have a part number for the muffler?

I haven't been able to find it anywhere.

Thanks!!

[Donnyparks]

This may help

http://www.mercruiserparts.com/Show_...=THROTTLE+BODY

[boatwakes]

go to perfprotech.com and look up by serial number on intake manifold link.