Based on old data and the recent litterature, we suspect the existence of a poorly documented low temperature magnetic phase transition (T<30K) in colossal magnetoresitve Pr1-xCaxMnO3 manganites spawning between x~0.33 to x~0.45 doping levels. We therefore propose neutron powder diffraction experiments aimed at accurately determining the changes of magnetic structure in a prototype x=0.375 sample, as well as to map this new phase in the (x,T) phase diagram.