OPERATION TROUBLES AND ACTIONS Engine 3 q ( ): Always contact your Komatsu distributor when dealing with these items. q In cases of abnormalities or causes which are not listed below, contact your Komatsu distributor for repairs.
3-131 Problem Main causes Remedy Engine oil pressure monitor lights up •Engine oil pan oil level is low (suck- ing in air) •Clogged oil filter cartridge •Defective tightening of oil pipe, pipe joint, oil leakage from damaged point •Defective engine oil pressure sen- sor •Defective monitor •Add oil to specified level, see CHECK BEFORE STARTING •Replace cartridge, see EVERY 500 HOURS SERVICE (•Check, repair) (•Replace sensor) (•Replace monitor) Steam spurts out from top of radiator (pressure valve) •Cooling water level low, leakage of water •Loose fan belt •Dirt or scale accumulated in cooling system •Clogged radiator fins or damaged fins •Defective thermostat •Loose radiator filler cap (high-alti- tude operations) •Defective water level sensor •Defective monitor •Check, add water, repair, see CHECK BEFORE STARTING •Check fan belt tension, adjust, replace •Change coolant, flush inside of cooling system, see WHEN REQUIRED •Clean or repair, see EVERY 500 HOURS SERVICE (•Replace thermostat) •Tighten cap or replace packing (•Replace sensor) (•Replace monitor) Radiator water level monitor lights up Engine does not start when starting motor is turned •Lack of fuel •Air in fuel system •Defective fuel injection pump or defective nozzle •Starting motor cranks engine sluggishly •Preheating monitor does not light up •Defective compression •Defective valve clearance •Add fuel, see CHECK BEFORE STARTING •Repair place where air is sucked in, see EVERY 500 HOURS SERVICE (•Replace pump or nozzle) •See ELECTRICAL SYSTEM •See ELECTRICAL SYSTEM (•Adjust valve clearance) Exhaust gas is white or blue •Too much oil in oil pan •Improper fuel •Set oil to specified level, see CHECK BEFORE STARTING •Change to specified fuel Exhaust gas occasionally turns black •Clogged air cleaner element •Defective nozzle •Defective compression •Defective turbocharger •Clean or replace, see WHEN REQUIRED (•Replace nozzle) (•See defective compression above) •Clean or replace turbocharger Combustion noise occasionally make breathing sound •Defective nozzle (•Replace nozzle)