The instantaneous crankshaft torque has been measured with a crankshaft integrated torque sensor on a V8 Truck Diesel Engine subjected to cylinder unbalance. The results indicates that the torque signal is well suited for detecting steady state unbalances. With an empirical model of the engine type, the torque signal can be used to estimate the IMEP unbalance in each individual cylinder. This way unbalances as small as 3% of the actual load can be detected. In the case of intermittent unbalance it is verified that the torque instantaneously reflects the changes in IMEP unbalance.