Noticed this knocking/rumbling noise today.Couldn;t fathom it out.When I parked I turned the mid-lights off and it stopped,turned back on and noise started again.Any suggestions very welcome.Hope nothing serious.Thanks.

 

Weird. What Mazda?

Probably it's either the alternator is falling off, or is self-destructing.

PAS pump fell off my MX-5 & alternator fell off my S2000. Fours vibrate a lot at high rpm...

 

Mazda 6.
Thanks.Better take it to garage tomorrow.Had it a month,but 3 month warranty.