Because of considerable importance of induction motors in different industries, fault detection of these motors has gained importance in the literature. One of the attractive approaches in this regard is motor current signature analysis. Thanks to simplicity and its lower cost, this method has been preferred compared to the other methods. In this paper, first, a model in which stator turn fault was taken into account is presented. Then, by stator current analysis using empirical mode decomposition (EMD), intrinsic-mode functions of the signals are derived. By selection of the calculated IMF in the first row of the EMD, its instantaneous frequency (IF) is estimated using adaptive IF estimation. Variation of the estimated IF is utilized for detection of different stator turn faults. The method is evaluated using plenty of simulations and some experiments.