Unusual 'intake' sound

[uk215m3]

Hi all, i have an issue trying to track down concerning an unusual sound coming from the intake 'system'.

Plenum etc was all off during a recent service, however 300 or so miles later the car has developed this sound, i have searched and only found comments around 'whistling' and the issue with the seal at the rear of the plenum. This is not that i believe.

The sound is best discribed as a 'hooting' type sound akin to (if anyone has ever done it... likely need to be my age! LOL) putting a blade of grass between your thumbs and blowing, or a paper kazoo with a comb and piece of paper.

Can't belive im posting this on here... LOL. Go to 1:43 in this video (no the car doesnt play the tune...LOL)

https://www.youtube.com/watch?v=1Y-T8cRpt94


Most notable at the slightest throttle opening between 2500-3500 rpm.

Any ideas gladly taken

[amrazM]

check the obvious, check the big hose at the back of the plenum it takes force to clip it on, check that the plenum is evenly seatly on all 8 of the rubbers for the throttles, check the intake connections. if all checks out pull the plenum, one of the rubbers is likely flattened.

[nick3753]

Originally Posted by amrazM

check the obvious, check the big hose at the back of the plenum it takes force to clip it on, check that the plenum is evenly seatly on all 8 of the rubbers for the throttles, check the intake connections. if all checks out pull the plenum, one of the rubbers is likely flattened.

This. Your plenum isn’t seated correctly. It might be rubbing on one of the strut braces. I’ve had the issue before with the same buzzing type sound.