Mazda 6 Strange Noise Identification

Aircon compressor or some sort of valve?

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "TheScullster" saying something like:

You have a beepus-beepus nesting under your dash. I suggest calling Wile E. Coyote immediately.

I had an odd noise (on an escort diesel) somewhat similar recently, a tiny stone was stuck in the alternator belt! never seen it before and probably never will again.

TheScullster laid this down on his screen :

I had what sounded like a very quiet trickling water noise from what I thought was around the bulkhead. It took several thousands of miles before I worked out the noise was just a squeak from between dash panels, due to slight body movement. A thumb on the dash stopped it instantly. Could your problem be something similar?

"Harry Bloomfield" wrote

Thanks Harry

I have experienced that exact same sound on occasions - quite disconcerting! Looking around the car for running water source.

But no, this is something completely different although similarly unrelated to engine speed. Last time I heard it, it seemed louder and is definitely more audible outside the car.

Phil

something which can make odd noises at odd intervals is the exhaust recirculation system, old fiestas make all sorts of strange puffing noises when cold which can be traced to the recirc system. In your case I would try removing the auxiliary belt and run the engine to see if the noise still occurs.