For the past few weeks, my 2003 Saturn Ion has started making a knocking sound. I mainly notice it when I first turn on the car or I’m idling or going at slow speeds. Once my car gets above 30 mph the sound goes away. When I open the hood and listen to the sound, it is loudest to the left of the engine block. Any thoughts on what this could be? Still drives fine but not sure if this is a worrisome sound/problem or not. Thanks

 

By the left side you mean the belt end of the engine? If so you need to have the timing chain checked before it breaks and bends all the valves. Quit driving it until you do.

 

Record this for us. Start and idle 5 seconds, take to 3000 rpm for 5 seconds. Do a snap throttle also.
This will help us a lot.