Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

spark knock

  1. Engine/Spark Knock?

    OEM Issues
    I'm new to this so bare with me. I have a 2003 GMC Envoy sitting at approx. 96,000 miles, when I bought it in August last year it had 92,000. When we got it, it had a slight knocking in the motor, mainly when it was idling. Almost sounded more like a tap so I decided it needed better oil and...
Top