Observations in the daws magnetosheath with the LASL/MPI fast plasma experiment on ISEE 1 and 2 reveal the existence of two distinct states of plasma flow within the sheath: 1) a ''quiet'' state; and 2) a ''disturbed'' state. Energetic ions in the range of 3-40 keV are the distinguishing feature of the disturbed state. Long period (~ 1 minute) fluctuations in plasma density, temperature, flow speed, and flow directions occur simultaneously with the appearance of these high energy particles. The most likely explanation of these observaons is that the energetic ions are produced in the vicinity of the bow shock under certain (unspecified) interplanetary conditions, and the fluctuations in plasma flow are produced locally by the interaction of the energetic ions with the ambient plasma.