A.引擎條件--2011年出廠五缸D4渦輪增壓柴油引擎、改原廠SAM動力程式、最大增壓值2.2bar、保養及操駕情況正常、平均速度約34km/hr、平均油耗約10.3km/L，GPS最高速度235km、長期使用全國加油站超級柴油，里程約137,000km引擎開始出現症狀。
B.引擎症狀--介於冷啟動(每天第一次發動)與熱啟動(水溫約80。c以上)之中溫啟動(水溫約40〜80。c)時，怠速不穩定，rpm約650〜750轉之間跳動，造成引擎抖動不順(同時排氣變臭)，持續約一、二十秒後，隨著水溫提升，引擎運轉才慢慢正常，rpm約720上下5轉輕微跳動，無論市區慢速或國道高速，行駛狀況均正常，但退檔大腳加速瞬間，容易噴出黑煙。
(2)瞭解問題：
A.初期以電腦診斷，未發現故障訊息，車廠表示可能是EGR管阻塞，等14萬公里保養清除積碳後，怠速不穩應該會改善。但本人半信半疑，因為以本人駕駛習慣及車況，透過DPF炭微粒濾清再生系統，EGR管不太可能被積碳阻塞。
B.以前每一萬公里保養時，都會買原廠的「柴油燃料活化劑」添加於油箱(一罐好像670元)，但最近二、三萬公里都沒添加任何柴油精，自從發生怠速不穩後，每次加油都添加廉價的柴油清潔劑(3M及STP廠牌都使用過，一瓶約150元)，不過症狀並未改善。
C.作14萬公里保養時，發現EGR管還算乾淨，不像早期滿滿黑炭淤泥，但保養完畢啟動引擎，怠速不穩症狀仍然存在，最後插電腦檢測，出現第三缸噴油嘴故障訊號，原因為阻塞或其他損壞，車廠建議更換噴油嘴，連工帶料費用可能近3萬元，當下不敢決定。
(3)解決問題：
A.為了瞭解噴油嘴阻塞的修復，上網查到這輛災情慘重的寶馬120D，但想想我的車還沒那麼嚴重：
https://www.mobile01.com/topicdetail.php?f=275&t=4039221
B.後來看到這篇國外相關資訊(原文及翻譯如下)，所以決定購買專用的噴油嘴清潔劑試試看：
『Diesel engines are extremely popular today, simply because they are economical and have a lot of torque. On the other side, turbocharged diesel engines can have similar or even better performances than petrol engines. In general, diesel fuel and gasoline are made from the same crude. However, these fuels have different characteristics, with makes diesel and gasoline powered engines very different. A bad thing is that both of them have drawbacks. In a case of diesel engines, these drawbacks are more severe. Within this guide, you will learn about the best diesel injector cleaners and their innumerable benefits.』
『今天柴油引擎非常受歡迎，簡單來說，因為它們是經濟的並且具有大扭力。 另一方面，渦輪增壓柴油引擎可以具有與汽油引擎相似或甚至更好的性能。 一般來說，柴油燃料和汽油由相同的原油製成。 然而，這些燃料具有不同特性，使得柴油和汽油動力引擎非常不同。 一個壞事是，他們都有缺點。 在柴油引擎的情況下，這些缺點更嚴重。 在本指南中，您將了解最好的柴油噴油嘴清潔劑及其無數的優點。』
『Problem with the deposits
The main issue, all diesel engines have the deposits that occur inside of an engine. The most common type of deposits is those around fuel injectors. The sad truth is that every diesel engine has this problem, and it occurs after a longer period of use, so older cars with diesel engines usually have this issue. As the result, the engine will increase the fuel consumption and reduce its power. Simply said, it will be less economical and the car will be slower.
Keep in mind that the aforementioned deposits occur no matter where and what type of diesel fuel you use. However, in some countries, where fuel has lower quality, these deposits are a more common issue. This means that you should clean the injectors from these deposits more often.』
『淤積(積碳)問題
主要問題是，所有柴油引擎都會有內部產生的淤積物。 最常見的淤積物類型是在燃料噴射器周圍。 可悲的事實是，每具柴油引擎都有這個問題，並且發生在長期使用之後，因此柴油引擎的老車通常會有這個問題。 因此，引擎將增加燃料消耗並降低功率。 簡單地說，這將會不太經濟，車子會更慢。
請記住，無論使用何種類型的柴油燃料，上述淤積物都會發生。 然而，在一些燃油品質較低的國家，這些淤積物更是一個常見的問題。 這意味著您應該更經常清除這些噴油嘴的淤積物。』
『Solutions to clean the deposits
One of the ways to clean fuel injectors is to take a car to a professional garage. They use ultrasonic waves to clean the debris. Although, this is a good way, it is expensive and it isn’t especially good. Another way is to dissemble the fuel injectors and clean them by yourself. Although, this is the cheapest solution, you must have more than needed knowledge. Also, this is a time consuming process. The best and the simplest way to clean the fuel injectors is to use injector cleaners. These are chemicals that are added to the fuel. While the engine is running, these cleaners will remove the debris.
Keep in mind that cleaners don’t have any side effects to your car. They are specially designed in order to remove the debris around fuel injectors and after that they will burn and be eliminated. As the end result, you get more power, due to the fact engine is restored to the original state and the fuel consumption is going to be reduced. No matter which diesel car you have, you can use these cleaners.
Over time, older cars lose their power. For example, if a car had 200 PS as a brand new, after 10-15 years it will have 150 PS. This reducing cannot be prevented, but there are techniques that can help you. Once again, diesel injector cleaners can restore that power. According to a research, they can restore up to 30 PS! Of course, the factory power of your car is something that determines the amount of restored power. In addition, the car will have better combustion and starting the engine will be easier.』
『清潔淤積物(積碳)的解決方案
清潔噴油嘴的方法之一，是將汽車送到專業車廠。他們使用超音波清潔廢渣(積碳及其他淤積物)。雖然，這是一個好方法，但費用昂貴，也不是特別好。另一種方法是拆下噴油嘴自己清潔。雖然，這是最便宜的解決方案，但你要有更多的必要知識。而且，這是一個耗時的過程。最好及最簡單的方法是，使用噴油嘴清潔劑。這些是添加到燃料中的化學品。當引擎運轉時，這些清潔劑將會清除廢渣(積碳及其他淤積物)。
請記住，清潔劑對你的車沒有任何副作用。它們是專門設計用來清除噴油嘴周圍的廢渣，之後它們會燒掉而被消除。最後結果是，你獲得更多的動力，因為事實上引擎回復到原來狀態，並且油耗將會減少。無論你有什麼柴油車，你可以使用這些清潔劑。
隨著時間的經過，老車會逐漸失去動力。例如，如果一輛新車有200 PS(馬力)，10-15年後它只剩下150 PS(馬力)。這種動力減少是不能防止的，但有技術可以幫助你。再說一次，柴油噴油嘴清潔劑可以回復這種動力。根據一項研究，它們可以回復高達30 PS(馬力)！當然，你車子的原廠動力，是決定回復動力數值的條件。此外，汽車將有更好的油耗，且啟動引擎將更容易。』
『Additional benefits of the diesel injector cleaners
Beside the aforementioned benefits, the cleaners offer a few more advantages. The first thing you should know is that they will clean the whole fuel system, including the hoes, pipes and fuel pump. This means that all deposits will be removed. In addition, these cleaners protect the fuel system, so it will be immune to the corrosion and forming of deposits.
The black smoke, on the exhaust system is usually connected to a bad fuel or fuel system. Diesel injector cleaners can eliminate this issue as well. On the other side, they will reduce the noise, an engine makes. At the same time, they will provide an extra amount of lubrication to the fuel, so the engine will last longer.』
『柴油噴油嘴清潔劑的附加優點
除了上述好處之外，清潔劑還提供了更多的優點。 你應該知道的第一件事是，它們會清潔整個燃油系統，包括噴孔、油路和燃油幫浦。 這意味著所有的淤積物都將被清除。 此外，這些清潔劑可以保護燃油系統，因此它可避免腐蝕和淤積物的形成。
排氣系統的黑煙，通常與不好的燃油或燃油系統有關。 柴油噴油嘴清潔劑也可以消除這個問題。 另一方面，它們會減少引擎運轉產生的噪音。 同時，它們也會為燃油料提供額外的潤滑，因此引擎壽命可以更長。』
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※後記：
(1)被車廠建議後，一度想網購D4拆車件噴油嘴，後來覺得沒必要動手術，不過是噴油嘴輕度阻塞，對症下藥即可：
(2)使用進口柴油噴油嘴清潔劑，混合燃油跑了四、五百公里後，中溫啟動之怠速不穩，已獲得改善：
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■■最新後記：清潔劑只是治標不治本，更重要的問題是→你看不見的汽缸壁裂縫（請參考下列連結）
https://www.mobile01.com/topicdetail.php?f=339&t=6505130
