Engine

Engine noise, lower end - Excessive clearance MEASURE the piston pin bore and the light double knock or between the piston and piston pin in 2 directions on each side. sharp rap sound. Occurs the piston pin REFER to the appropriate 303-01 mostly with a warm engine Section for specifications. at idle or low speeds in drive. Increases in relation to engine load. Associated with a poor lubrication history

Engine noise, lower end - Excessive clearance CARRY OUT the Connecting Rod light knocking noise. The between the Bearing Journal Clearance procedure. noise is most noticeable connecting rod REFER to: Connecting Rod Bearing when the engine is warm. bearings and the Journal Clearance (303-00 Engine The noise tends to crankshaft System - General Information, General decrease when the vehicle Procedures). is coasting or in neutral

Engine noise, lower end - Worn or damaged CARRY OUT the Crankshaft Main deep knocking noise. The crankshaft main Bearing Journal Clearance procedure. noise is most noticeable bearings REFER to: Crankshaft Main Bearing when the engine is warm, Journal Clearance (303-00 Engine at lower rpm and under a System - General Information, General light load and then at float Procedures).

Engine noise, rear of Damaged INSPECT the flywheel/flexplate for wear engine - knocking noise at flywheel/flexplate or damage. INSTALL a new rear of engine flywheel/flexplate as necessary. Refer to

the appropriate section in Group 303 for the procedure. TEST the system for normal operation after the repair.

Engine vibration - vibration Excessive engine pulley CARRY OUT the Engine Accessory Test. felt at all times runout REFER to: Noise, Vibration and

Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing). INSTALL a new engine pulley as necessary. Refer to the appropriate section in Group 303 for the procedure. TEST the system for normal operation after the repair.

Damaged or worn CARRY OUT the Engine Accessory Test. accessory component REFER to: Noise, Vibration and

Harshness (NVH) (100-04 Noise, Vibration and Harshness, Diagnosis and Testing). REPAIR or INSTALL a new component as necessary. TEST the system for normal operation after the repair.

Engine vibration - at idle, a Cylinder misfire Using the scan tool, CARRY OUT the low-frequency vibration cylinder power balance and the relative (5-20 Hz) or mild shake compression test. REPAIR as necessary. that is felt through the Refer to the appropriate section in Group seat/ floorpan 303 for the procedure. TEST the system

for normal operation after the repair.

Engine or torque VERIFY the torque converter to converter out of crankshaft pilot clearance is correct. balance REPAIR as necessary. RE-INDEX the

torque converter on the flex plate by 120 degrees for a 3- bolt converter or 180 degrees for a 4-bolt converter. Refer to the appropriate section in Group 307 for the procedure. TEST the system for