Knocks at Idle Hot

^ Detonation or spark knock. Check operation of ignition controls or knock sensor circuit.
^ Loose torque converter bolts.
^ Exhaust leak at manifold. Tighten the exhaust manifold bolts and/or replace the gasket.
^ Excessive connecting rod bearing clearance. Replace bearings as necessary.
^ Excessive piston pin clearance.
^ Excessive crankshaft thrust bearing clearance.
^ Bent connecting rod.