The colour of engine oil can change both in cars with a diesel engine and in petrol ones. But what does the black colour and thick consistency that you noticed while checking the oil level mean? From this text you will learn everything important on the subject of black engine oil.
Diesel fuel in the engine - what is it for?
For correct operation, a combustion engine needs engine oil, which provides lubrication for all moving parts. If the unit were not equipped with any lubricant, it could lead to overheating and rapid wear of the individual components that come into direct contact with one another. The oil therefore provides the necessary glide and reduces the temperature generated during engine operation.
Black oil in the engine - where is it located?
As a rule, engine oil is stored in the oil pan. Its capacity is variable and ranges between 4 and 6 litres depending on the type of car, its make and model. The moment you start the engine, the oil pump, with the help of a special tube, begins to draw the oil directly from the pan. The lubricant then goes to the oil filter and is cleaned there of all kinds of dirt and metal shavings that are produced during use of the vehicle. The next direction is the engine channels. Once the oil flows through the channels, it returns to the oil pan and the whole process starts again, providing the unit with the necessary glide and regulating the temperature.
Black colour of engine oil - causes
The black colour of engine oil, regardless of whether you have a vehicle with a diesel drive or an ordinary “petrol car”, should arouse your interest. After all, it is not an entirely normal situation. Below we have prepared for you a list of potential faults that may be the cause of the change in the oil colour.
- Normal wear - let’s start with a “fault” that results from normal use. It is not entirely a breakdown, but it is certainly worth mentioning when creating this type of list. Well, engine oil darkens between changes and this is a normal phenomenon. The oils used today are equipped with special performance-enhancing additives whose task is to accumulate contamination and metal shavings, which can naturally lead to you finding black oil in a petrol engine or a diesel.
- Dirty filter - this type of element is tasked with filtering out the contaminants present in the oil. The longer the filter goes unchanged, the worse it works. Over time it becomes clogged and stops separating contaminants from the lubricant. If you do not replace the filter, dangerous waste can get into the engine and damage its delicate components.
- Infrequent oil changes - the oil should be changed regularly. If during an inspection you notice that the substance on the dipstick is black and thick, it means you should immediately attend to changing the oil. How often you have to add new lubricant depends on the type of oil and the manufacturer’s recommendations.
- An illuminated warning light - if you notice a warning light in the driver’s cabin responsible for signalling the oil condition, it means you should take an interest in the condition of the oil pump and check whether a possible leak has occurred. Do not ignore this signal, because it may be a harbinger of a serious breakdown.
- Low oil level - in a situation where there is too little oil in the oil pan, it may mean that you are dealing with a leak. In such a situation, contact with a mechanic is essential; they will check the condition of the pan thoroughly and diagnose the problem. Remember that the oil level should be constant, and its drastic changes are often a harbinger of problems.
Black oil in the engine - stay calm
As you can see, the colour of diesel fuel can darken over time and this should not raise any concerns. However, take an interest in the situation when you notice that the oil is very thick and black. Darkening over time is something normal, but such a drastic change of colour is a clear signal that something bad is happening.
