406 3.0 V6 Auto noise

My 406 V6 makes a noise which I originally thought came from the
automatic gearbox. It sounds like a mixture between a grating and a
groaning noise - very hard to describe accurately! It only starts up
after driving the car for a little while - usually it has kicked in
within 3 minutes. It then comes and goes, sometimes quieter, sometimes
noisier. I have recently read that the air conditioning makes a similar
noise at times - does anyone have experience of this car, this noise,
this problem etc etc?
Thanks
Fin

 

I get a droning noise which i have always blamed on the tyres. It seems to
start after new tyres have been on the car for a few thousand miles (I think
the rear) and is more or less noticeable depending on the road surface.

Peter

 

Thanks Peter,
I have now confirmed that my noise is indeed coming from the
air-conditioning compressor. Apparently a nbadly designed pipe is the
cause of it, and when the climate control is switched to ECO mode, the
noise disappears. Which is great, because my car is now like a ghost -
silent, smooth and fast.

 

What year is your car ?

 

1998, so its the Mk 1.