The paper presents the results of studies of diffusion combustion of gaseous methane in the presence of external pressure pulsations with low amplitude on the flame plume. The analysis of the temperature field and the stabilization time of the combustion mode has been carried out. It is established that the presence of pressure pulsations leads to characteristic changes in the temperature field, which are expressed by a growth of the temperature pulsation amplitude, corresponding to the frequency of external influences. A characteristic time for stabilizing the combustion regime from the moment when there is no external influence to their appearance is determined.