I have a worrying sound from my 1.6 Litre NB 2000 mx-5 107.000km (Timing belt changed at 80.000km at a workshop by previous owner) . I have searched a bit around after people with a similar problem but with no luck. So asking you clever people out there is my only solution other than opening the top cover. (or paying alot to a mazda workshop)
I tried to find the source of the sound with use of a stethoscope. (I tried: waterpump, alternator, steering pump and varius spots on the timing belt cover) I did find a spot where the sound i was looking for was amplified. The sound is coming from behind the timing belt cover near the crankshaft sprocket.
I can hear the sound when the engine is warmed up and can be heard best when idling.
Here is the sound: http://vocaroo.com/i/s0eWqhvLWxhQ
Need more info just ask.