loud wind noise in the cockpit C5 2010 3 litre diesel

[Peter Dowdle]

As of yesterday I now have a loud wind noise which develops at speeds over about 40 km . It appears to have something to do with cockpit air pressure because as soon as i wind a window down the noise disappears.
It seems to be coming from under the dash board towards the left hand side of the car.

Regards Peter Dowdle

[GiveMeABreak]

Ok, so first have a look in the passenger glovebox. At the top, there should be a small circular plastic knob. This is the control that allows air from the heating system to pass into the glovebox to keep items cool and can be turned to block or allow air passage. It might be air from this area that you can hear. Try turning it one way fully or the other to see if this stops the noise.

If not I'd start looking at the door seal. If this has come away in even a small area it can cause noises from the external air entering the cabin.

[wheeler]

I was driving a brand new Renault Traffic hire van for a few days recently. If the blowers were switched off the wind noise in the cab was horrendous if the system was not set to recirculate. The problem was if the fans werent on the recirc function would automatically switch back off after 5-10 minutes & had to keep being switched back on.

[GiveMeABreak]

Because it's unhealthy to breathe in stale exhaled air and carbon dioxide - especially in a confined space, so it's set to switch back to fresh outside air after a few minutes. I only ever use recycled setting in extended traffic jams in a city, but thankfully that's never an issue where I live in the mountains.