The collision-induced dissociation (CID) dynamics of the Ar-2(+)+Ar collision system are investigated at different Ar-2(+) internal energy distributions in a guided-ion beam (GIB) apparatus. The internal energy of reactant ions, assumed vibrational in a first approximation, is controlled by varying the position of ionization in a supersonic jet, electron impact ion source. Three conditions are investigated: cold, in which the ions are produced as vibrationally relaxed as possible; intermediate, in which a substantial shift in the CID onset is observed; hot, in which the apparent CID threshold is at near thermal collision energies. The vibrational distribution of the Ar-2(+) ions is probed at the same conditions by measuring the kinetic energy release of photofragment Ar+ following (2)Sigma(g)(+)<--(2)Sigma(u)(+) photodissociation. The derived internal energy distributions are then used to model the observed CID cross sections with a modified line-of-centers approach to assess vibrational effects in the single-collision cross sections. The intermediate CID cross sections are consistent with a negligible vibrational enhancement beyond the statistical predictions. A substantial increase in cross section is observed when going from intermediate to hot conditions, despite a weak increase in internal energy, as apparent from the photodissociation measurements. Contributions from metastable states, not registered in the photodissociation experiment, can explain this disparity.