GM Service Manual Online
For 1990-2009 cars only

Light knock hot may be caused by one or more of the following conditions:

    • Loose torque converter bolts
    • Exhaust leak at the manifold (tighten the bolts, replace the gasket if necessary)
    • Excessive rod bearing clearance, (replace the bearings as necessary)
    • Detonation or spark knock, refer to Engine Controls.