A diesel engine which is in proper running shouldn’t give out any smoke. If you see smoke coming out from your engine, keep in mind that diesel smoke tells you a story. The following are a few instances which could cause smoke to come out of a diesel engine.
However if your diesel engine is relatively old and you might see a puff of smoke coming out of it every now and then. The reason for this could be a lag in the turbo charger’s air flow.
White smoke from a diesel engine
If you spot white smoke coming from your diesel engine it could suggest a problem with the injectors. It’s an indication that the fuel is not being burnt off in a proper manner. Any diesel fuel which is not being burnt finds its way out of the exhaust. Some of the common reasons for white smoke could be any of the following.
- Injectors which may be damaged on or the verge of needing a replacement
- Some problems with injection timings
- Low compression in the cylinder
- Damage to the lining of the cylinder
- Problems with the head gasket
- Low fuel pressure in the fuel pump
- Damage in the fuel pump
Black smoke from a diesel engine
Black smoke indicates high level of carbon in the exhaust particles. When the diesel fuel in a cylinder burns down long chain carbon molecules into several smaller ones. These smaller molecules are a combination of water and carbon molecules. Anything that goes wrong during the combustion process can cause the hydrocarbon molecules to be left intact and then expelled in the form of a black smog. This can lead to sever for of air pollution due to the release of carbon mono oxide into the atmosphere. However, diesel engines these days are fitted with a catalytic converter or a diesel exhaust fluid which helps send the exhaust back into the conversion chamber to be broken down further.
The following could be some of the reasons for black smoke coming from a diesel engine.
- Air cleaners which have become clogged and just need a simple cleaning
- Injectors which have been damaged
- Damaged inter charger or turbo cooler
- Problems with valve clearance
- Buildup of excessive sludge in the engine
- Problems with the piston rings
Blue smoke from a diesel engine
Though quite rare but there could be an instance where you see blue smoke coming out of a diesel engine. Blue smoke can indicate burning of oil. Though it’s not something serious but it shouldn’t be ignored either. The following could be a few reasons for blue smoke emanating from the engines.
- Damaged piston rings which are worn out can cause blue smoke
- Worn out cylinders which might be damaged due to over use
- An engine which has become over filled with oil
- Improper oil not recommended for a diesel engine
If you see any of the above kind of smoke emanating from a diesel engine you should make sure you get it checked as soon as possible.