Low molecular weight polystyrene melts were subjected to shearing flow which was periodically halted. Weak maxima in both the viscosity and normal stress were observed upon startup of the flow, notwithstanding the absence of entanglements. The strain associated with the viscosity maxima was independent of shear rate, and consistent with the overshoot strains for entangled polymers. The stress overshoots disappeared or were of weaker intensity When the flow was resumed after a brief interruption. For sufficiently long rest periods between Row, the original behavior was reproduced. The time scale for recovery of the maxima was about the same as that for relaxation of the stress from steady state flow. This differs from the behavior of entangled polymers. (C) 2001 The Society of Rheology.