White vapors, usually referred to as 'white smoke' by the uninformed, are completely normal in cool\cold weather when starting an infernal-combustion engine, be it gasoline-fueled or Diesel-fueled:
a - when a running engine is turned off, as the engine\exhaust system cools, raw atmosphere with included water vapor (humidity) is drawn into the intake, also the exhaust system - start the engine from cold-start, and the hot exhaust evaporates the moisture in the exhaust system, giving white water-vapors - gasoline engines, with hotter exhaust gas temperatures at idle, create denser vapors over a shorter period of time - Diesel engines, with lower btu output at idle, take longer to heat up the exhaust system so the vapor is lighter - yer 6.5 don't warm up very quickly, even in warm weather, particularly when unloaded, not working
b - infernal combustion engines require increased advance and fuel rates at cold start -
- the automatic choke on carburetors is proof enuff of that, and EFI systems have their own methods, with the Idle Air Control and Computer Controlled Spark referenced to the Engine Coolant Temperature and Intake Air Temperature sensors and the heated 02 sensor - gasoline is highly volatile, burns rapidly, and is easily ignited by the ignition spark, so combustion temperatures are easily managed - result: minimal un-ignited fuel vapors out the exhaust
- Diesels have their own systems, with increased injection advance and injected fuelrate referenced to ECT and IAT, with glowplug system response referenced to those same sensors for increased glow duration - Diesel fuel is ignited by high compressed-air temperatures in the cylinder, so when the intake air and engine coolant and sump oil and cylinders and heads and injectors and injection pumps and lift pumps and fuel lines and fuel in the tank are all cold, cylinder temps can easily drop below threshold of combustion - result: unignited fuel passed into the exhaust system and out the tailpipe = raw white fuel vapors, mixed with the normal water vapors in the exhaust system - glow plugs and heated fuel serve to alleviate this problem, as does the engine coolant heater in the cylinder block - other Diesel systems use an intake air heater along with fuel heating and the coolant heater
Black smoke, or unburned raw fuel where the fuel was at or above combustion temperature and the flame went out, is caused by two conditions:
a - too much fuel, either from excess injection from faulty sensor feedback ,or reduction of air\fuel mixture, as from dirty air filter, low\no Boost from ruptured intake ducting or loss of wastegate control, burns until oxygen volume in the cylinder is depleted, flame goes out, remaining unburned fuel component is carbonized - result: black smoke out the exhaust - EFI and EFI\mechanical (6.5L) systems manage this better than the mechanical systems, so the initial symptom from restricted air intake will be more haze, easily recognizeable at nite in the headlites behind the rich emitter, and\or, particularly from loss of Boost, black smoke out the exhaust
b - water in the fuel\contaminated fuel quenches the flame B4 the fuel charge is depleted, or cannot sustain combustion - flame goes out, heated unburned fuel component is carbonized - result: black smoke out the exhaust - EFI systems do not manage this condition any better than mechanical systems, as watery fuel is not conducive to efficiently converting fuel to btu's
White vapors are water or\and unignited fuel, usually increasing in cooler weather, but also from failing or defective glow plugs
Black smoke is unburned fuel, usually any season
a - when a running engine is turned off, as the engine\exhaust system cools, raw atmosphere with included water vapor (humidity) is drawn into the intake, also the exhaust system - start the engine from cold-start, and the hot exhaust evaporates the moisture in the exhaust system, giving white water-vapors - gasoline engines, with hotter exhaust gas temperatures at idle, create denser vapors over a shorter period of time - Diesel engines, with lower btu output at idle, take longer to heat up the exhaust system so the vapor is lighter - yer 6.5 don't warm up very quickly, even in warm weather, particularly when unloaded, not working
b - infernal combustion engines require increased advance and fuel rates at cold start -
- the automatic choke on carburetors is proof enuff of that, and EFI systems have their own methods, with the Idle Air Control and Computer Controlled Spark referenced to the Engine Coolant Temperature and Intake Air Temperature sensors and the heated 02 sensor - gasoline is highly volatile, burns rapidly, and is easily ignited by the ignition spark, so combustion temperatures are easily managed - result: minimal un-ignited fuel vapors out the exhaust
- Diesels have their own systems, with increased injection advance and injected fuelrate referenced to ECT and IAT, with glowplug system response referenced to those same sensors for increased glow duration - Diesel fuel is ignited by high compressed-air temperatures in the cylinder, so when the intake air and engine coolant and sump oil and cylinders and heads and injectors and injection pumps and lift pumps and fuel lines and fuel in the tank are all cold, cylinder temps can easily drop below threshold of combustion - result: unignited fuel passed into the exhaust system and out the tailpipe = raw white fuel vapors, mixed with the normal water vapors in the exhaust system - glow plugs and heated fuel serve to alleviate this problem, as does the engine coolant heater in the cylinder block - other Diesel systems use an intake air heater along with fuel heating and the coolant heater
Black smoke, or unburned raw fuel where the fuel was at or above combustion temperature and the flame went out, is caused by two conditions:
a - too much fuel, either from excess injection from faulty sensor feedback ,or reduction of air\fuel mixture, as from dirty air filter, low\no Boost from ruptured intake ducting or loss of wastegate control, burns until oxygen volume in the cylinder is depleted, flame goes out, remaining unburned fuel component is carbonized - result: black smoke out the exhaust - EFI and EFI\mechanical (6.5L) systems manage this better than the mechanical systems, so the initial symptom from restricted air intake will be more haze, easily recognizeable at nite in the headlites behind the rich emitter, and\or, particularly from loss of Boost, black smoke out the exhaust
b - water in the fuel\contaminated fuel quenches the flame B4 the fuel charge is depleted, or cannot sustain combustion - flame goes out, heated unburned fuel component is carbonized - result: black smoke out the exhaust - EFI systems do not manage this condition any better than mechanical systems, as watery fuel is not conducive to efficiently converting fuel to btu's
White vapors are water or\and unignited fuel, usually increasing in cooler weather, but also from failing or defective glow plugs
Black smoke is unburned fuel, usually any season
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