Method for manufacturing a composite material part includes injecting a slurry containing a refractory ceramic particle powder into a fibrous texture, draining the liquid from the slurry that passed through the fibrous texture and retaining the refractory ceramic particle powder inside said texture so as to obtain a fibrous preform loaded with refractory ceramic particles, and demoulding of the fibrous preform. The method includes, after demoulding the fibrous preform, checking the compliance of the demoulded fibrous preform. If the preform is noncompliant, the method also includes, before a sintering, immersing the demoulded fibrous preform in a bath of a liquid suitable for decompacting the refractory ceramic particles present in the fibrous preform, and additionally injecting a slurry containing a refractory ceramic particle powder into the fibrous preform present in the mould cavity.