One problem related to engine knocking noise has been reported for the 2006 Saturn ION. The most recently reported issues are listed below.
2006 Saturn Ion. Consumer writes in regards to vehicle electrical system issues. Recently, the emergency brake the consumer stated the check engine light illuminated twice and finally, the fuel injectors were replaced. Recently, the emergency brake light illuminated and stayed on without the emergency brake being pulled. Also, when she pushed the shifter knob, there was a noise in the steering column. There was an issue with the electrical power steering. It would go out and resume normal operation, while driving. The consumer stated she heard a knocking noise, when she drove over a bump and the check engine light illuminated again. Updated 08/06/14.