發動機高溫的檢查與診斷

Inspection and diagnosis of engine High temperature

冷卻水過熱是發動機冷卻系中較為常見的故障。冷卻水高溫，不僅使潤滑油變稀而降低潤滑質量，加劇運動件表面的磨損，而且容易導致黏缸、活塞環卡死等故障發生。因此，行車中如發現水溫過高。應及時進行檢查，做出診斷，並採取相應措施。將故障予以排除，以保證汽車能正常執行。

Overheating of cooling water is a common fault in engine cooling system。 The high temperature of cooling water not only makes the lubricating oil dilute and reduces the lubrication quality， aggravates the wear of the surface of the moving parts， but also easily leads to the sticking of the cylinder and piston ring。 Therefore， if the water temperature is found to be too high in the driving。 Inspection should be carried out in time， diagnosis should be made， and corresponding measures should be taken。 Remove the faults to ensure the normal operation of the car。

（1）冷卻系水量的檢查

（1） Inspection of cooling system water quantity

發動機冷卻系缺水。使冷卻水不能迴圈散熱，造成發動機溫度過高。冷卻系缺水的原因有兩種可能：一是冷卻水在正常消耗中沒有及時給予補充；是冷卻水嚴重滲漏。

The engine cooling system is short of water。 The cooling water can not be circulated and dissipated， resulting in too high engine temperature。 There are two possible reasons for the lack of water in the cooling system： one is that the cooling water is not replenished in time in the normal consumption； it is the serious leakage of the cooling water。Inspection and diagnosis of engine High temperature

發動機正常工作時，冷卻水溫度應在80°C~95°C之間，此時會有部分冷卻水被蒸發，若長時間不作補充，一旦水泵泵不上水，就會造成發動機因缺水而發生高溫的人為故障。

。 When the engine works normally， the cooling water temperature should be between 80°C~95°C， at this time， some cooling water will be evaporated， if not replenished for a long time， once the pump is not filled with water， it will cause the engine to have high temperature man-made failure due to lack of water。

如果冷卻系密封效能遭受破壞，使冷卻水嚴重漏失，也會造成缺水高溫，如水泵水封處磨損過度、溼式缸套因氣蝕造成的小孔、缸體出現裂紋、缸

If the sealing performance of the cooling system is destroyed and the cooling water is seriously leaked， it will also cause water shortage and high temperature， such as excessive wear at the water seal of the pump， small holes caused by cavitation in the wet cylinder liner， cracks in the cylinder block， and

缸套水封破損等。後三者不但能造成發動機高溫，且因冷卻水漏進軸底殼，與潤滑油混合，是潤滑油變質，會導致燒瓦、抱軸等嚴重事故。如拔出量油尺，油麵明顯升溫，潤滑油發白，這說明冷卻水漏進軸底，應找出漏油部位修復換新油。換下機油透過沉澱使水油分離，取上層油加溫30到50攝氏度，將水分蒸發，如該機油與新機油一樣，可繼續使用。

The water seal of the cylinder liner is damaged， etc。 The latter three can not only cause high temperature of the engine， but also cause serious accidents such as burning tile， holding shaft and so on because of the leakage of cooling water into the shaft bottom shell and mixing with the lubricating oil。 If the oil gauge is pulled out， the oil surface is obviously heated up and the lubricating oil is whitened， which indicates that the cooling water leaked into the bottom of the shaft， and the oil leakage part should be found out to repair and replace the new oil。 Replace the oil by precipitating to separate the water oil， heat the upper layer of oil 30 to 50 degrees Celsius， evaporate the water， if the oil is the same as the new oil， can continue to use。

（2 ）散熱器的檢查和維修

（II） Inspection and maintenance of radiators

如果發動機在冷卻液充足的情況下發生高溫。就需對散熱器進行檢查。。散熱器芯部被雜物堵寒汽車長時期行駛在泥療多塵、多雜草等路面上，散熱器被塵t草葉、民蟲等塞滿，造成散熱不良。遇到此類情況，可在發動機熄火後。從散熱器後面用壓縮空’吹或用低壓水流沖洗，以除去雜物，然後再用軟毛刷清理芯部。

If the engine is full of coolant， high temperature occurs。 The radiator needs to be checked。 The radiator core is blocked by sundries for a long time on the road surface， such as dust therapy， weeds and so on。 The radiator is filled with dust t grass leaves， folk insects and so on， resulting in poor heat dissipation。 In the event of such a situation， the engine can be turned off。 Blow from behind the radiator with compressed air or rinse with low pressure water to remove sundries， and then clean the core with a soft brush。

散熱片變形粘連。由於機械損傷等原因。造成散熱片堆積或黏結在一起，使氣流不能通暢穿過散熱器芯，造成散熱不良。解決的方法是用薄鋼片（如廢鋼鋸條）小心地將散熱片撥至原位。恢復散熱片的平直形狀

。 The heat sink deforms and adheres。 Due to mechanical damage and other reasons。 Resulting in heat sink accumulation or bonding together， so that the air flow can not pass through the radiator core， resulting in poor heat dissipation。 The solution is to carefully set the heat sink to its original position with thin steel sheets， such as scrap saw blades。 Restore the flat shape of the heat sink

散熱器芯管堵塞。駕駛員長期向冷卻系加註硬水。泥沙含量大的河水。使冷卻水中的泥沙與汙垢等黏附於芯管內壁致使芯管不通暢或被堵塞。檢查的方法是：發動機走熱後，用手觸控芯管的上部與下部，注意其之溫差。正常情況下，上、下部有溫差，但相差不大。若感到芯管上、下溫差明顯（因下部無熱水透過），則說明該芯管堵塞；若堵塞芯管超過芯管總數的15。冷卻效果將大為降低。此時，應將散熱器拆下，置於含有5%-10%的蘇打熱水（80到90攝氏度 ）中沖洗，並用鋼釺疏通芯管。然後再用熱水沖洗。

The radiator core pipe is clogged。 The driver poured hard water into the cooling system for a long time。 A river with a high sediment content。 So that the sediment and dirt in the cooling water adhere to the inner wall of the core tube， resulting in the core tube not smooth or blocked。 The method of inspection is： after the engine is hot， touch the upper and lower parts of the core tube with your hand， and pay attention to the temperature difference。 Under normal circumstances， there is a temperature difference between the upper and lower parts， but the difference is not significant。 If the temperature difference between the top and bottom of the core tube is obvious （because there is no hot water passing through the lower part）， the core tube is clogged； if the blockage core tube exceeds 15% of the total number of core tubes。 The cooling effect will be greatly reduced。 At this point， the radiator should be removed， washed in soda hot water （80 to 90 degrees Celsius） containing 5% less than 10%， and brazed through the core pipe with steel。 And then rinse it with hot water。

（3）風扇與風扇皮帶的檢查

（3） Inspection of fans and fan belts

現代汽車的發動機冷卻系一-般都是風冷 和水冷相結合。風冷是否正常，對冷卻效果極為重要。 若皮帶打滑，則會影響風冷效果。因此，應經常檢查皮帶的張緊度與損壞等情況。如發現過鬆應予調整。若橡膠脫層或纖維層折斷，則應更換。

The engine cooling of modern cars is a combination of air cooling and water cooling。 Whether the air cooling is normal or not is very important to the cooling effect。 If the belt skidding， it will affect the air cooling effect。 Therefore， the tension and damage of the belt should be checked frequently。 If it is found to be too loose， it should be adjusted。 If the rubber is delamination or the fiber layer is broken， it should be replaced。

其次是檢查風扇葉片的旋轉情況。現在許多車型都採用矽油風扇離合器，在發動機低溫時自動斷開風扇的動力傳遞。使發動機快速升溫。減少冷態時的快速磨損。但在發動機達到正常工作溫度時，風扇應進人正常旋轉。若因風扇離合器中的矽油被甩幹，或過敏雙金屬片發生故障而造成風扇轉速不能達到標準時，冷卻系即發生高溫。該故障的檢查方法是：

The second is to check the rotation of the fan blade。 Nowadays， many models use silicone oil fan clutch to automatically disconnect the power transmission of the fan when the engine is low。 Make the engine heat up quickly。 Reduce the rapid wear and tear in cold state。 However， when the engine reaches the normal working temperature， the fan should rotate normally。 If the silicone oil in the fan clutch is thrown dry or the allergic bimetallic plate fails， the cooling system will be high temperature if the fan speed can not meet the standard。 The fault is checked by：

車輛在停車過夜之後，風扇離合器的主動盤和從動盤之間仍殘留有矽油，由於矽油的黏度高。這時撥轉風扇比較吃力。啟動發動機，以中速運轉1~2min，使工作腔內矽油返回貯油室。立即熄火。此時用手撥動風扇。應轉動輕鬆，用力較小。

After the vehicle stops overnight， there is still silicone oil between the active disk and the follower disk of the fan clutch， because of the high viscosity of the silicone oil。 At this time， it is more difficult to dial the fan。 Start the engine and run at medium speed for 1 min to return the silicone oil in the working cavity to the oil storage chamber。 Put off the fire at once。 At this time， use your hands to move the fan。 The rotation should be easy and the force should be small。