X5 30D - Strange idle noise
 

Hi guys,

Looking for some help in identifying a strange noise my car has developed during hot idle.

It seems to be coming from the rear of the engine and in the video below you can see one of the hoses moving in what i consider a suspicious way.

It's a 2008 xDrive30D - any help would be appreciated.

It feels like cabin heat control valve.There is a electric water pump that circulates water for the cabin heating and there is a valve which opens and closes to maintain user programmed temperature.

Try to shut shown the cabin fan or try to turn the temperature down to minimum and see if that noise still persists.

I have just had my 2007 E70 30D (65000 miles) in for BMW UK warranty work for the exact same noise, they said it was the EGR circuit causing it so replace the EGR valve (not sure if that's the exact truth but they have cleared the noise).

If you Google E70 or BMW quacking noise you'll get some hits on it also.

Now that's a funny noise...

I have no direct experience on this, but the EGR valve could in fact be the reason.

In the EU version the EGR is vacuum controlled. The vacuum acts on a membrane that pulls the rod controlling the poppet valve for the EGR. If the membrane has a tear it can vibrate and produce a quacking noise.