  Temperature dependent magnetization, muon spin rotation and $^{57}$Fe
M\"ossbauer spectroscopy experiments performed on crystals of intermetallic
FeGa$_{3-y}$Ge$_{y}$ ($y=0.11,0.14,0.17,0.22,0.27$, $0.29,0.32$) are reported.
Whereas at $y=0.11$ even a sensitive magnetic microprobe such as $\mu$SR does
not detect magnetism, all other samples display weak ferromagnetism with a
magnetic moment of up to 0.22 $\mu_B$ per Fe atom. As a function of doping and
of temperature a crossover from short range to long range magnetic order is
observed, characterized by a broadly distributed spontaneous internal field.
However, the $y=0.14$ and $y=0.17$ remain in the short range ordered state down
to the lowest investigated temperature. The transition from short range to long
range order appears to be accompanied by a change of the character of the spin
fluctuations, which exhibit spin wave excitations signature in the LRO part of
the phase diagram. M\"ossbauer spectroscopy for $y=0.27$ and 0.32 indicates
that the internal field lies in the plane perpendicular to the crystallographic
$c$ axis. The field distribution and its evolution with doping suggest that the
details of the Fe magnetic moment formation and the consequent magnetic state
are determined not only by the dopant concentration but also by the way the
replacement of the Ga atoms surrounding the Fe is accomplished.
