Whirring Noise...

Dxthomas · #1 10th July 2016, 07:14 AM

I've noticed a very faint whirring noise coming from somewhere around the rear centre vents area.

It's a bit like the noise a DVD player sometimes makes when spinning a disc. Or maybe a bit like a fan / rotary kind of noise.

It does get slightly louder at higher speeds, but the revolutions don't seem to change.

The noise dies completely away when slowing right down, circa. below 10/15 mph.

The noise doesn't occur when revving the engine at a standstill.

Any ideas?

snapdragon · #2 10th July 2016, 08:16 AM

When you turn the thumbwheels on the vent to increase/decrease airflow, you are operating a rheostat - that sends resistance signal to the HVAC controls which in turn send current to motors which control a peg that sticks out from inside the dash and into the vent to move it back and forth - maybe someone took out the vents and refitted without engaging in the peg as it is easily done. Is there any clicking?

Dxthomas · #3 24th July 2016, 04:23 PM

Just thought I'd close this one out...

The noise is a worn centre prop shaft bearing. New prop shaft circa. £1200 from Audi, hoping to get just the bearing replaced though.

snapdragon · #4 25th July 2016, 01:28 PM

Hello, how did you find it was that?
I have a similar thing on mine now for the last few days.
A bit like metal being turned on a lathe but quieter.
It is not very noticebale under 45mph.