Noise at end of revs?

[Jordanian]

I've noticed the last few days that if I take the car upto the shift light in 2nd and 3rd (not tried other gears) there is a noise during gear change. The only way to describe the noise is its like having a dump/ recirc valve?

Any ideas? Other than the the car runs great.

 

[Willis]

Do a search, it's been covered a few times on here but I can't remember what it is off the top of my head...

 

[X82]

Acoustic valve on the inlet closing

 

[dredd123]

Wow I've got this as well - what is this acoustic valve and what is the solution to get rid of the noise?

 

[GrumpyTwig]

Wow I've got this as well - what is this acoustic valve and what is the solution to get rid of the noise?

The black 'trumpet' on the nearside of the engine bay, put a finger up it (ooo err missus) and you'll feel the butterfly valve. It's vacuum controlled so it shuts (I think) above a certain RPM.

You can just remove it, supposedly in the Renault bumf it's part of the design to reduce noise at low revs.

 

[djjackwilson]

I've noticed it alot more since I removed my centre box

 

[Foxspeed]

The black 'trumpet' on the nearside of the engine bay, put a finger up it (ooo err missus) and you'll feel the butterfly valve. It's vacuum controlled so it shuts (I think) above a certain RPM.

You can just remove it, supposedly in the Renault bumf it's part of the design to reduce noise at low revs.

other way - opens at higher revs....

 

[ryan197]

the valve is closed upto 4000rpm, then it opens. i just removed the vacuum hose to the solenoid and blanked the pipe off, so its open all the while, also fed a cold air feed from lower in the bumper to the valve