TM-9-2815-220-24 Maintenance Manual for AVDS-1790-2CA AVDS-1790-DA and AVDS-1790-2DR Engines Download
Page 124 of 1563
TM 9-2815-220-24 ENGINE NOISY OPERATION 0015 00 MALFUNCTION 1: (Continued) Knock or tapping sound. PROBABLE CAUSE CORRECTIVE ACTION a. (Continued) Rocker arm assembly defective or out of adjustment. (1) (Continued) Locate faulty cylinder as follows: PROCEDURE OBSERVATION ANALYSIS Cylinder Compression Test Method: Perform Cylinder Compression Test (WP 0033, Cylinder Compression Test). Note cylinder with low pressure (below 330 psi at 140-180 cranking rpm). Indicates faulty cylinder, damaged rings, piston, valve, connecting rod or tight rocker arm (no valve clearance). PROBABLE CAUSE CORRECTIVE ACTION (1) Locate faulty cylinder as above. b. Excessive intake or exhaust valve clearance or damage. (2) Adjust valve clearance (WP 0034, Intake and Exhaust Valve Clearance Adjustment). (1) Inspect, repair, or replace valve and/or cylinder (WP 0133, Cylinder Assembly Replacement). c. Rocker arm assembly defective. (2) Replace rocker arm (WP 0104, Rocker Arm Assembly and Cover Replacement). (1) Locate faulty cylinder as above. d. Connecting rod, piston, ring damage, or loose piston pin. (2) Check for damage (WP 0143, Connecting Rod Assembly and Associated Parts Repair and WP 0142, Pistons, Rings, and Associated Parts Replace/Repair). e. Crankshaft bearing damage. (1) Check for damage (WP 0138, Crankshaft Main Bearing Inspection). f. Worn or damaged gears or bearings. (1) Check for damage (WP 0178, Disassembly/ Assembly Procedure Sequence for the AVDS 1790-2 Engine). WP 0015 00-2