English for automobile engineering - Unit 7: Finding a fault in a car

ENGLISH FOR AUTOMOBILE ENGINEERINGLECTURER: LANG VAN THANG FACUTY OF MECHANICAL ENGINEERINGHO CHI MINH UNIVERSITY OF INDUSTRYEMAIL: thang.langvan@hotmail.comSUBJECTS UNIT 7MAY 14, 2011ENGLISH FOR AUTOMOBILE ENGINEERINGFINDING A FAULT IN A CARPresentationIf your car doesn’t start in the morning, you should check three things first: the battery, the fuel level and the spark plugs. It is easy to repair three faults. If the battery is flat, you should recharge it. If it doesn’t work, you should replace it. If the petrol tank is empty, fill it up. If the spark plugs are dirty, clean them, and if the gap in a spark plug is too narrow or too wide, adjust it to the correct width.Read the text and match these pictures in Figure 7.1 with words from the passage:If your car still doesn’t start, the petrol pump may be broken, or the fuel pipe may be blocked. If the pump is broken, it must be repaired or replaced. If the fuel pipe is blocked, take it off and unblock it.PresentationIf there is a loud CLICK! When you turn the key, the starter motor may be jammed. If it is, you can try to release it by pushing the car forwards and backwards (in 2nd gear). If the car still doesn’t start, the starter motor should be repaired or replaced.Practice 1Read the text and then complete the table 7.1:Petrol will not burn unless it is mixed with air: normally the proportion of air to petrol required to burn fuel completely is 15 (air): 1 (petrol). This means that 1 kg of petrol should be mixed with 15 kg of air. More air or less petrol gives a weak mixture i.e. an air: petrol ratio greater than 15:1. Less air or more petrol gives a rich mixture i.e. an air : petrol ratio of less than 15:1.A weak mixture, which will mean very slow combustion, will result in high fuel consumption, low engine power and possibly overheating of the engine. A rich mixture, which will also mean slow combustion, will similarly result in high fuel consumption and low engine power. A further indication of rich mixture is black or sooty exhaust gas.Mixture strengthCombustionExhaust gasEffectsVery weak, e.g. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __Very rich, e.g._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ __Practice 1Practice 2Use Table 7.1 to complete this text:High fuel consumption and low engine power can be caused by either _ _ _ _ _ _ or _ _ _ _. If the exhaust gas is black, this will indicate _ _ _ _ _. If the engine overheats, this will probably mean the mixture is too _ _ _ __ .Practice 2Now use the text above and Figure 7.2 to complete the text below: Damage to sparking plugs can be caused by _ _ _ _ _ _, or _ _ _ _ _ __. If the sparking plug has _ _ _ _ _ _ _ and _ _ _ _ _, this will _ _ _ _ _. If the sparking plug __ _ _ __. If _ __ ___ _ _ _ __ _ _ _ _ _ _ _ _ __ __ _.Practice 3Use Table 7.2 and Figure 7.3 to complete the text:FaultReasonsRemedyExcessive fuel consumptionChoked air cleanerLeaking carburetorIncorrectly adjusted carburetorIncorrectly type of silencerClean air cleanerCheck and tighten screwsAdjust as necessaryFit correct silencerLow engine powerWeak mixture due to jammed float needleWeak mixture due to air leak at carburetor jointRemove float needle and cleanCheck and tighten all screwsPractice 3Use Table 7.2 and Figure 7.3 to complete the text: Excessive fuel consumption can be caused by one of the following reasons: a choked air cleaner, _ _ _ _ _ _, _ _ _ _ _ _ or _ _ _ _ _ _. If the air cleaner is not choked, examine the carburetor, since high fuel consumption could indicate either _ _ _ _ or _ _ _ _ . Check and tighten all screws and adjust as necessary. If, after checking the carburetor, fuel consumption is still high, it will probably mean _ _ _ _ .Practice 3Use Table 7.2 and Figure 7.3 to complete the text:Low engine power _ _ _ _ _ _ _ _ by a weak mixture. A weak mixture __ _ _ _ that the float needle is stuck, in which case remove the float needle and clean it.If, after _ _ _ _ _ _ _, engine power is still low, this _ _ _ _ _ _ _ that there is an air leak at the carburetor joint. In this case _ _ _ _ _ _ _ _ _ _ _ _.Development Read the text and then complete Table 7.3:A petrol and air mixture is drawn into the cylinder, compressed and ignited by a spark. First, the petrol and air mixture ignites near the spark. Then, heat given off by the burning fuel particles cause adjacent particles to ignite. Consequently, a flame front spreads through the combustion chamber. Development As a result of thermal radiation, increased pressure and hot pockets in the combustion chamber, a second ignition and flame front may occur in the unburned mixture. Sometimes this may lead to violent combustion of the unburned mixture, causing knocking in the engine.CauseEffectsHeat given off by burning fuel particles_ _ _ _ _ _ __ _ _ _ _ a flame front spreads through the combustion chamberThermal radiation, _ _ _ _ _ __ and _ _ _ _ __ a second ignition and flame front_ _ __ _ 3. _ _ ___