e70 3.0l d humming/droaning from engine

[redjim]

Hi guys,
I have a humming droning noise coming from what sounds like the left hand side of the engine and it seems to get louder whist driving and can be heard quite loudly in the cabin. It seems to be coming from the bottom of the engine as you can hear it louder from under the car. I thought it was a wheel baring at first whislt driving but have noticed it is coming from the engine. It is quieter at idle but gets louder whist driving at normal road speeds. it also seems to disappear at motorway speeds.

Any ideas?
car is march 2007 3.0l d se

cheers

[X5Sport]

Front or rear of the engine?

Have you checked all the engine shields are tightly fixed?

[redjim]

rear bottom i think

[X5Sport]

Not sure what's back there, but gearbox - as in torque converter - might be the issue, though lower on the possibility list.

All of the ancillary drives are at the front of the engine.

Could be a driveshaft bearing on the inner CVJ?  The thought has just occurred about tyres.  We have had reports of diff whine being caused by incorrect tyre types or wide tread wear variations.  The transmissions are not very tolerant of non-OEM tyres being used - though not all makes suffer - or if the front to rear wear is quite large - such as 7mm rear and 4mm front or vice versa.  If in doubt check as it can result in a diff shattering.

Worth checking for loose underbody shields though.

[redjim]

i tried to make a video of the sound but its hard to hear anything but the diesel engine noise. its a deeper sort of humming slight muffled sound.

[redjim]

https://www.youtube.com/watch?v=Rfr3iMWqdV8

[Tommy]

Are tyre tread depths equal front and rear ?