There are two common causes of that noise on the K-series engines. One
is a "collapsed" hydraulic tappet - it could be cleared by a good oil
change, but if the problem is mechanical, the tappet will need to be
replaced.

The other cause is the anti-backlash gear on the camshaft drive; this
is an annoyance but does no harm if you can live with it. The
replacement part is not terribly expensive, but it is a lengthy job to
get at it to do the work.

--- In mazdamx3ownersuk@..., "monsoonmarty"
<monsoonmarty@y...> wrote:
>
> Hi folks, anyone out there know the reason and cure for said above
> noise. Its been doing it since I bought the car last year. Any
> suggestions/remedies would be appreciated...
>
> Cheers
>