Two color, pump-probe laser experiments on the similar to 100 fs time scale have been applied to examining the dynamics of vibrational wave packets in the C (1) Pi(u) state of Cs-2. Wave packets consisting of more 20 C state vibrational levels are produced with an initial pulse having a central wavelength between similar to 620 and 680 nm. The temporal history of the wave packet is inferred from the time and energy-integrated photoelectron signal produced when the excited state is photoionized by a time-delayed pulse centered at 605, 610, 615, 617, or 620 nm. Because of the difference in equilibrium internuclear separations for the Cs-2(C) and Cs-2(+)(X) states (Delta R(e) approximate to 0.75 Angstrom), wave packets are readily observed (signal-to-noise ratio >10) without the need to resort to mass selection techniques. Frequency analysis of the wave packet data shows a dominant (fundamental) component that decreases from 29 to similar to 28.3 cm(-1) as the pump wavelength is tuned from 627 to 641 nm. Other spectral modes at similar to 23.5 and similar to 34 cm(-1) and a weaker term at twice the fundamental frequency are also observed and quantum mechanical calculations of the wavepacket motion are in accord with the experimental results.