Diesel Smoke tells YOU a Story
Basically, smoke from a diesel engine indicates that something is not right.
It should be taken as an indication that there is a problem existing (ordeveloping), that will potentially shorten the engine life, or result inunnecessary costs. It should be regarded as an opportunity to take measuresthat will save you money in both the long term and also the short term. At theleast, that smoke may be due to a simple problem, that is causing poorcombustion efficiency…and costing you in excessive fuel bills (eg carboned upengine from excessive idling, stop start operation or short run times). At theother end of the scale, it may be your last chance to act, before acatastrophic engine failure occurs (eg piston seizure, valve or turbochargerfailure).
A diesel engine in good condition should produce no visible smoke from theexhaust, under most operating conditions. A short puff of smoke when an engineis accelerated under load may be acceptable, due to the lag before the turbochargerspeed and air flow is able to match the volume of diesel injected into thecylinders. That would only apply to older technology diesel engines, but withmodern type diesels, no smoke at all should be evident.
There are three basic types of diesel smoke, identifiable by their colour...Black, Blue and White
In the outlines below we explain what causes each colour of diesel smoke andprovide you with links to high quality products that will help you solve theseproblems....
Black smoke is the most common smoke emitted from diesel engines. It indicates poor and incomplete combustion of the diesel fuel.There are many causes, including…
Incorrect timing
Dirty or worn injectors
Over-fuelling
Faulty turbocharger (ie not enough air to match the fuel)
Incorrect valve clearance
Incorrect air/fuel ratio
Low cylinder compression (eg sticking piston rings or worn components)
Dirty air cleaner
Restricted induction system (eg system too small or kinked inlet piping)
Other engine tune factors
Poor quality fuel
Excessive carbon build up in combustion and exhaust spaces
Cool operating temperatures
Obviously, worn or damaged components must be replaced, and the earlier youidentify and fix the problem, the less damage will be done. Keep on top ofengine tune issues, including valve adjustments, and regular servicing of air,fuel and oil filters. Do not buy fuel from suspect outlets. Dirty components,such as injectors can be easily restored to full cleanliness by using aneffective and reliable fuel system cleaner. If you choose from our range ofproducts, Cleanpower is what you need.
Cleaning of internals of engines has usually only been possible at overhaul,however, Cost Effective Maintenance provide two products to enable vehicle andequipment owners to quickly, safely and cheaply restore full cleanliness tocombustion and exhaust spaces (FTC Decarbonizer) as well as piston rings, oilpumps, oil galleries, oil coolers, piston skirts, valve gear, etc (Flushing OilConcentrate).
Black smokeis high in carbon or soot, which is an undesirable product of dieselcombustion. Now, the combustion of diesel is a complicated process of breakingdown the various hydrocarbon fuel molecules into progressively smaller andsmaller molecules, by burning in the presence of oxygen. The main and ideal endproducts of combustion are CO2 and H2O (carbon dioxide, the greenhouse gas andwater). It is believed that the last step in the process is carbon monoxide(the poisonous gas) to carbon dioxide. This is also the slowest step by far,and when combustion conditions deteriorate some upstream bottle necking occursin the chain of combustion reactions. This results (according to someauthorities) in polymerization of smaller partly burnt molecules into muchlarger ones, which become visible as soot, or black smoke.
Blue smoke is an indication of oil being burnt. The oil can enter the combustion chamber for several reasons.
Worn valve guides or seals
Wear in power assemblies (ie cylinders, piston rings, ring grooves)
Cylinder glaze
Piston ring sticking
Incorrect grade of oil (eg oil too thin, and migrating past the rings)
Fuel dilution in the oil (oil thinned out with diesel)
At cold start, blue smoke is often evident, and can reflect reduced oilcontrol, due to fouling deposits around piston rings or cylinder glaze (whichis actually carbon deposited in the machined cylinder crosshatching. These tinygrooves actually hold a film of oil, which in turn completes the seal betweenthe combustion chamber and the oil wetted crankcase). Blue smoke should not beevident at any time, but it is worth noting, that engines with good soundcompression can actually burn quite a lot of oil without evidence of bluesmoke. Good compression allows oil to burn cleanly, as part of the fuel. It’snot good though!
Once again, restore physical cleanliness to all components. Replace worn partswhere necessary. In some situations, where the engines are pretty worn, but youjust need to keep them in service, cleaning with the previously mentionedproducts, followed by effective additional anti-wear protection, will reduceinternal stresses on all those tired components, providing extended servicelife. Our AW10 Antiwear
White smoke occurs when raw diesel comes through the exhaustcompletely intact and unburned. Some causesof this include…
Faulty or damaged injectors
Incorrect injection timing (could be a worn timing gear or damaged crankshaftkeyway).
Low cylinder compression (eg caused by leaking or broken valves, piston ringsticking, cylinder and/or ring wear, or cylinder glaze)
When white smoke occurs at cold start, and then disappears as the engine warmsup, the most common causes are fouling deposits around piston rings and/orcylinder glazing. Use of our Flushing Oil Concentrate and FTC Decarbonizeraddress these respective problems.
Water entering combustion spaces will also create white smoke. Faulty headgaskets and cracked cylinder heads or blocks are a common cause of water entry,and are often to blame. Unfortunately, expensive mechanical repair is the onlyproper solution here.
Check the link at the top to find out more about Cost Effective's Diesel SmokeSolutions