| The main problem with a diesel engine is - getting | | | | next starting of the engine. The advantage of this |
| it to start. The problem is compounded ifa. The | | | | system is that the operation is fully automatic |
| engine happens to be an indirect injection modelb. | | | | whenever the engine is started and heating cycle |
| The temperature is near or below freezing pointc. | | | | automatically operates as per the required time. |
| The engine is to be started with fuel other than | | | | This conserves battery power and increases the |
| diesel. | | | | life of glow plugs. Further it eliminates `white |
| To overcome this problem most diesel engine | | | | smoke' which causes harmful air pollution. This kind |
| vehicle manufacturers provide an engine heating | | | | of automatic system is more advantageous than |
| system and/or a provision to start the engine | | | | intake air heating system, which can not pre-heat |
| with ether or petrol and then change over to | | | | the chambers causing heating inefficiency. The air |
| diesel. Electric heating systems can be auto or | | | | heater is also far more costly than glow plugs and |
| manual. Electrical heating of the diesel engine is | | | | replacement is difficult. It also consumes more |
| done in several ways. Two of the most | | | | energy than direct heating through glow plugs. |
| commonly used systems are heating the | | | | Most manufacturers of indirect or direct injection |
| chamber with glow plugs and heating the intake air | | | | diesel engines are incorporating automatic engine |
| with an electric air heater placed in the intake | | | | heating systems of 12 or 24 Volt glow plugs but |
| manifold. | | | | some are also using a quick glow system through |
| In a manual heating system, a push button is | | | | 5.6V or 9 V systems for quick glow of glow |
| pressed to make the dashboard mounted glow | | | | plugs. With the quick glow system the controller |
| indicator to show the amount and duration of | | | | becomes more complicated and expensive. |
| glow being transmitted to the chambers through a | | | | Therefore the standard has become a normal |
| series of glow plugs. The advantage of this | | | | heating time of around 7/8 Sec. at 20 Deg. C. |
| system is that there is no complicated electronic | | | | The time-heat curve has been calibrated in the |
| glow control system. However the disadvantage | | | | controller to vary the heating time automatically |
| is that you try and heat on a hunch. If the button | | | | as per the engine temperature. In other words |
| is kept pressed for a longer time than necessary, | | | | the heating time will get reduced to a second |
| the battery will get drained and the life of the | | | | when the engine is in hot condition whereas the |
| glow plugs will get reduced. | | | | time will extend to as long as 30 Sec when |
| In an automatic engine heating system through | | | | starting conditions are extremely cold. |
| glow plugs, the heating is started automatically as | | | | Additionally, for extremely cold climates, |
| soon as the ignition switch is turned on. The CPU | | | | manufacturers are providing simultaneous heating |
| controller (timer) either senses the actual | | | | during cranking after pre-heat period is over and |
| temperature of the engine through a sensor | | | | again post heating time after the diesel engine has |
| mounted on the engine block or in the cooling | | | | started. This simultaneous & post heating |
| water jacket, or it senses indirectly with an | | | | eliminates the emission of `white smoke' due to nil |
| internal device in the controller (timer). On the | | | | or partial combustion of the fuel, in extreme cold |
| basis of the `feed back' of the sensor, the | | | | climates. However to retain the prospect of |
| controller (timer) automatically determines the | | | | future parts sales, manufacturers do not allow |
| amount of heat duration to be given to the glow | | | | interchangeability of the heating systems between |
| plugs. At the end of the required heating cycle the | | | | different vehicles. This escalates prices and often |
| controller gets automatically switched off and | | | | local technicians do not know how to check, |
| indicates that pre-heating is over and the engine is | | | | replace and calibrate these systems. |
| ready for starting. The controller waits for the | | | | |