Anything vibrating in the same frequency of spectrum that a knock sensor is designed can trigger the knock sensor.
Knock sensors picked up a binding water pump and tried to adjust the engine accordingly. Made the entire car rock at idle! Let's just say anyone who rode in the car at that time was less than impressed with the crown jewel of the BMW line-up! The defecytive WP can barely be turned by hand.
And in typical fashion that incident was followed shortly with a failed radiator!
What is your year and mileage?
If you haven't done the cooling system overhaul, here is the info:
Last edited by cn90; 09-27-2007 at 07:28 PM.