Diesel engine failure(1)
Automotive diesel engine always in the course of failure should be in accordance with the automotive fault diagnosis method for fault diagnosis, and then to the exclusion or repair and restore the normal engine operating conditions.
First, the engine failure
1 Diesel Engine Fault
(1) diesel engine starting problems: The main difficulties include diesel engine and diesel engine starting at room temperature starting difficulties in cold starting problems.
(2) idle speed instability: mainly refers to the engine idle speed instability, no idling and idling vehicles idling condition you fail.
(3) small and medium-load conditions job insecurity: the engine easier to turn off individual cylinders intermittent work, power output is unstable.
(4) lack of a large load of power: diesel high speed, high load conditions show weakness, and weak underpowered cars accelerate failure.
(5) diesel oil costs: costs of oil found in car use, car found in long-distance travel increased significantly hundred kilometers and other faults.
(6) diesel engine does not stop the oil flame: Turn off the engine does not stall the engine still running; continue to repeat the shutdown is still stalled.
2 Diesel specific failure
(1) diesel Speed: engine running at high speed conditions, the speed suddenly increased their own, can not control, or even damage the machine.
(2) diesel engine shutdown: diesel engine at high speed and high load conditions, the sudden loss of control and shutdown, engine no longer starting.
Second, the diesel engine fault diagnosis
Ten flexible use of fault diagnosis method for diesel engine troubleshooting common faults and fault diagnosis. Diesel works decided that some failure is more obvious and relatively easy to determine, for example, can see the diesel engine emission tobacco smoke color, listening to the sound engine, hand temperature and touch somewhere other methods to determine the perception of vibration.
1 diesel engine exhaust smoke color
Observation of diesel engine exhaust smoke color, to determine whether the work of the engine failure, is a simple and effective way.
The engine at normal operating temperature, its exhaust smoke color is colorless or pale gray, so not completely colorless colorless, not as colorless as the gasoline engine, but with a touch of gray in colorless, it is normal exhaust smoke color; the engine at idle when the exhaust smoke color may be heavier, high-speed high load may be heavier, to observe the normal exhaust smoke color, can the non-normal exhaust smoke color with a clear understanding.
(1) exhaust black smoke. Diesel exhaust is the main fuel too thick black smoke, poor fuel mixture or the formation of incomplete combustion and other causes.
Diesel engine running at normal temperature, high load conditions or conditions often associated with accelerating the phenomenon of black smoke, is generally caused due to excessive fuel injection. If the engine trouble, and adjusted properly, and the smoke limiter is working properly, diesel engine under heavy load can reduce the phenomenon of black smoke, smoke gray is more normal. Can be adjusted to light gray smoke that is the best.
In the cold season, and some diesel engine cold start to smoke a lot of smoke, thick smoke and some even much more, looks like smoke to take the same car crash, have not seen strange scary. This is mainly due to cold weather, low air temperature, intake air temperature is low, although the 6110 diesel engine air intake preheating unit, but may sometimes not work or the role of the low; diesel body cold, cold night, especially at night, has been completely cold, despite preheating incoming air has been cooled, causing the combustion chamber air temperature is low, the corresponding low-temperature lubricants, oil pan oil temperature is low, the lubricating oil channels and the surface oil film temperature is low, the engine running resistance, the corresponding speed is low; coolant temperature is low, slow heat engine; fuel temperature is low, poor injector spray atomization, combustible mixture formation is poor, making the combustion is imperfect; coupled with poor fuel quality, smoke on the Solstice. BF6M1013EC Germany Deutz diesel engine, the combustion chamber in the installation of a pen-cold start heater, heating to give the combustion chamber, which makes the cooler start and cold start warm-up process after the black smoke of diesel phenomenon to ease and can be quickly disappear.
For diesel engine cold start and continuation of black smoke failure for some time, it is difficult to adjust the methods to be resolved, only to wait about half an hour, the engine temperature is normal, and black smoke lessens and failure will disappear.
(2) blue smoke. Blue exhaust smoke, usually after prolonged use, the engine, slowly began to burn oil caused, with the blue smoke of the increase, more and more oil burning, a diesel engine maintenance should be considered.
Sometimes the fuel is mixed with water, or water leaking into the combustion chamber, causing burning of the change, diesel engine will take the light blue smoke.
(3) white smoke. White exhaust smoke is the smoke color is white, with colorless different, white is white vapor. White smoke that contains water or containing unburned fuel components. Diesel engine in cold weather running, the engine temperature is low, low exhaust temperature, water vapor condenses into water vapor to form a white exhaust smoke, is normal. When the engine temperature is normal, the exhaust pipe temperature is normal, still emit white smoke, the engine is not working properly, the failure may be caused by: fuel contains too much moisture; fuel pump pressure is too low; such as the fuel injector failure in poor atomization in the combustion chamber, fuel mixture caused by the formation of bad.
(4) gray smoke. Light gray smoke, diesel engine work is fairly normal, but increased gray smoke color is not normal or nearly black, black smoke in addition to the above-mentioned reasons, there may be poor intake air supply that is not good reasons. When removing the intake air filter, the exhaust smoke color to colorless even by the shallow depth, the air filter is clogged, you should check into the air causing poor reasons.
(2) diesel engine sound
The working principle of diesel over gasoline determines its sound great, when its failure would show up with greater abnormal sound, as long as careful monitoring, fault relatively easy to determine.
Abnormal sound of the engine means more listening, such as direct use of ears listening, this is the most used, and many abnormal sound can be heard directly from them; by means of listening to bar, screwdriver, tools such as hose and stethoscope monitoring unit subtle sound, may well be a good listener method, received directly ears to hear hear the sound.
(1) diesel engine working rough noise. When the governor is not adjusted correctly, excessive fuel injection, fuel injection too soon, the work may appear rude noise, significantly higher than normal engine sound. Especially when the engine speed and high load performance of the more obvious, should be properly adjusted.
(2) diesel engine knock noise. When the governor is too early to adjust the fuel injection when the pressure in the combustion chamber in the piston near TDC, the combustion chamber in the high rate of pressure rise, causing diesel knock. Knocking occurs in acceleration and high load conditions, such as knock often happens, it should be adjusted, or long-term damage to engine knock.
(3) diesel engine exhaust noise. Diesel exhaust noise is relatively high, requiring from the engine exhaust nozzle until the exhaust muffler exhaust outlet of the pipe is damaged and can not leak, such as in pipe joints leak noise will greatly increase the use of very unfavorable, replacement parts must be repaired.
(4) seated valve noise. The valve can be seated right ear to hear directly from the noise, with a long stick or screwdriver to listen to listen to hear more clearly, as heard valve noise is too large, it may be valve clearance is too large, you should re-adjust valve clearance; such as hear the valve seat noise, accompanied by engine failure and poor work, it may be valve clearance is too small, should be re-adjusted to the appropriate valve clearance gap and restore engine work.
(5) fuel injection system noise. Injection pump and injectors work, the stick can be used to listen to listen to the rhythm of the oil pump delivery valve injector fuel injection after the sound and the sound of the needle valve seat. If monitoring less than a fuel pump and injector road sound, but also work with engine failure and poor, may not be a cylinder fuel injection, does not work.
(6) diesel engine sound is not normal. Diesel engine work, the issue of rhythmic noise, engine speed changes when the normal speed of normal sound upgrade. The engine speed, the sound becomes crisp, “slightly, slightly” sound, it may be premature due to injection; sound becomes boring, “call, call” the sound and acceleration associated with weakness, it may be sprayed late due to the oil.