Charge air cooler faults in diesel engines are diagnosed following OBD standards. One charge air cooler fault occurs when debris blocks the charge air cooler. This leads to poor engine performance and emissions violations. An experiment has been designed to collect sensor data from a Cummins ISB5.9 liter diesel engine experiencing a charge air cooler fault. A symptom of the fault has been identified by analyzing the dynamics of the sensor signals using a technique called singular spectrum analysis. The resulting diagnostic strategy makes use of the oil pressure signal to generate symptoms of the charge air cooler fault.