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Smoke

This document discusses different types of exhaust smoke from diesel engines and their potential causes. White exhaust smoke can be caused by unburned fuel due to lack of heat, incorrect injection timing, or poor atomization of fuel. Black exhaust smoke usually indicates a lack of oxygen for proper combustion, which can result from a clogged air filter, issues with the turbo or intake system, or an excess of fuel. Blue exhaust smoke is caused by the engine burning oil, which can be due to worn piston rings, excessive crankcase pressure, or worn valve guides.

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696 views2 pages

Smoke

This document discusses different types of exhaust smoke from diesel engines and their potential causes. White exhaust smoke can be caused by unburned fuel due to lack of heat, incorrect injection timing, or poor atomization of fuel. Black exhaust smoke usually indicates a lack of oxygen for proper combustion, which can result from a clogged air filter, issues with the turbo or intake system, or an excess of fuel. Blue exhaust smoke is caused by the engine burning oil, which can be due to worn piston rings, excessive crankcase pressure, or worn valve guides.

Uploaded by

Joe
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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This is due to a air to fuel ratio imbalance, either the fuel system is delivering too much fuel into

the
engine or there is not enough clean air (oxygen ) a few things to look for :

•Faulty injectors (injectors need attention at about 100.000 to 120 000 miles)

•Faulty injector pump

•Dirty air cleaner

•Turbocharger or intercooler faulty

•Problems within cylinder head, valves clogged up due to faulty EGR (exhaust gas recycling unit)

Normally means that the fuel injected into the cylinder is not burning correctly. The smoke will burn
your eyes.

•Engine/pump timing out

•Fuel starvation to the pump causing the pumps timing not to operate correctly

•Low engine compression

•Water/petrol in the fuel

The engine is burning engine oil

•Worn cylinders or piston rings

•Faulty valves or valve stem seals

•Engine over full with engine oil

•Faulty injector pump/lift pump allowing engine oil to be mixed with the diesel

White Exhaust Smoke white smoke could indicate several problems, such as unburned fuel from lack of
heat, incorrect injection timing, poor atomization of fuel or coolant being burned during combustion.
White Smoke Due to lack of heat. When fuel is injected into a combustion chamber where there is
insufficient heat for ignition and combustion the fuel will not be completely burned resulting in White
Smoke. Low ambient temperatures (Winter Operation) make it more difficult for cylinder pressure to
generate enough heat, especially when starting the engine. Once the engine has warmed up the smoke
will normally disappear. Starting aids are used to reduce this problem (Glow plugs, intake heaters etc.)
Low compression pressures (worn engine) will not generate sufficient heat for efficient combustion and
can cause the engine to produce white smoke even at operating temperature.

White Smoke Due to Incorrect Injection Timing. If the fuel injection timing is retarted, the burning fuel
chases the piston down in the cylinder. When the exhaust valve opens, the heat escapes before the fuel
is completely burned. The unburned or partially burned fuel exits the exhaust as white smoke. With the
engine at operating temperature and under load, the white smoke may appear to be a gray color.

White Smoke Due to Poor Atomization of Fuel Poor atomization of the fuel may be caused by low
injection pressure. The fuel droplets are too large and therefore harder to ignite and burn. As a result
combustion is in complete resulting in White Smoke.

Black Exhaust Smoke Black exhaust smoke usually indicates there is not enough oxygen for proper
combustion.

Black Exhaust Smoke Can be The Result of Two Conditions. 1. A lack of air for the metered amount of
fuel. This could be due to a plugged air filter, a defective turbo or leaking intake system gaskets and
hoses on turbo charged engines.

2.An excess amount of fuel (overfuelling) for the amount of air an engine can supply. If the maximum
fuel setting is greater than the manufacturers specs or if pollution controls have been improperly
adjusted, there may not be sufficient air to burn all of the fuel.

Blue Exhaust Smoke Blue exhaust smoke is the result of an engine burning oil. Common causes include
worn piston rings, excessive crankcase pressure, worn valve guides or a defective turbo charger.

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