ARMY TM 9-6115-639-13 AIR FORCE TO 35C2-3-386-51 MARINE CORPS TM 10155A-13/1 Table 3-3.  Operator Level Troubleshooting (continued) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 10.    ENGINE EMITS WHITE SMOKE a.     Check engine oil level to see if it is too high. Refer trouble to unit maintenance level to drain and service engine oil. b.     Check for water in fuel filter / water separator (refer to para. 3-8). Drain water from filter separator by turning valve. c.    Refer trouble to unit level maintenance. 11.    ENGINE EMITS BLACK SMOKE a.    Check air filter for clogging or dirt. Remove filter and inspect (para. 3-9).  Replace filter as required. b.    Has engine run for prolonged periods at idle speed (no load)? Operate engine at rated load only. c.    Refer trouble to unit maintenance level. 12.    ENGINE WILL NOT START IN COLD WEATHER a.    Check that PREHEAT switch is in ON position. Place switch in ON position. b.    Check that proper fuel is being used for cold weather operation. Use proper fuel as noted on FUEL CAPACITY data plate (Figure 1-5). c.    Check for crimped or pinched fuel lines.  Check for clogs or frozen water in fuel lines, filter separator. Straighten flexible fuel lines.  Refer to unit level maintenance if fuel line or filter separator is frozen or damaged. d.    Refer trouble to unit level maintenance. 3-8 Change 1