obo110x

Hi,
I have a whine or droning noise from my engine (3.7l V8, 2004 D3) that is in tune with engine revs, a bit like a fan and I'm pretty sure it is one of the accessory driven parts.
It is worse when A/C Econ is off but this could just be the extra load of the compressor.
I disconnected the aux cooling fans and it is still present.
I've had the A/C serviced and it made no difference.

All systems function normally in the car. The sound a V8 makes is music but mine sounds awful at the moment.

The engine sounds fine when idling and the noise is only really evident inside the car.

The question is how do I determine the source of the noise?

Thanks in advance.