Reminis

I have this whirring noise coming from behind the lower left hand side (passengers in UK) foot well / bulk head.
It is not a really loud noise, but loud enough to know that all is not as it should be.

The noise is not related to the vehicle moving, the noise occurs when it is both stationary & moving to the same effect.

It is most noticeable when at low revs, just a little above tick over.
You can still hear it at tick-over but becomes more apparent when revs are increased to 1000-2000rpm.
Above this rpm you can still hear it but is not as loud.
I know the other engine noises can muffle it when above this rpm but it is genuinely not as loud in higher rpm but still present (not really noticeable above 3000-5000rpm.

Describing the whirring noise is hard to describe (so I have attached a clip) but I think it sounds similar to something like a fan rubbing on a shroud or something, except that is not where it's coming from.

Clip1 is from inside the car, pointing at where the sound is coming from in the footwell:-

Clip2 is from in the engine bay where I move the camera down to close where I think the noise is coming from:-

Could it be a bearing somewhere, an exhaust leak, an intake leak?

Any help would be greatly appreciated!

Maj. Dundee

Was your heater on at the time? If it was it could be the blower motor on the other side.

Reminis

Hi MD, no... It was not on, think you can se that in clip1, thanks for the idea though.

Maj. Dundee

Do you think the noise is originating from the eng. compartment or the passenger compartment?

Reminis

The engine compartment.

Maj. Dundee

What is this bobbing up and down?

Could the sound be coming from the front of the eng.?

Reminis

I think that that the bit moving is just me not holding the camera steady lol,
I couldn't remember seeing anything bobbing around in the engine bay otherwise I would have been a bit shocked.
I will check again tomorrow but I can 95% say that it was just my poor camera skills.

And the sound is definitely coming from the lower back end of the engine compartment.

Thanks again :-)

Maj. Dundee

Buy a cheap mechanics stethoscope and put it against the trans. bell housing.

Reminis

Good idea, I usually use a screwdriver for that but I certainly wont be able to fit my head down in the engine bay lol.

I was rather hoping someone would have had this fault before and can give me a diagnosis but it looks like I will have to solve it myself.
A unique problem on the ML430 that no one else has had, who'd believe it lol.

Cheers MD

Maj. Dundee

The tool is less than $15. Just get it and listen around.