By Andrea Hargraves 
All engines are designed to last as long as possible. However, this does not always happen. However, whether due to a random problem or some bad habits on the part of the users, a diesel engine can start to display unusual and worrying characteristics when it is on the verge of failure. These characteristics can range from concerns typical of any engine to issues completely unique to the diesel engine structure. So, if your diesel car is doing some of the things listed below, your engine is in trouble!
to caution! If your diesel car is doing this, then there is a problem with the engine!
High oil consumption
On average, diesel engines are larger and operate at higher temperatures than their conventional counterparts. After all, a diesel engine shines on long trips, so it needs more muscle and lubrication to maintain its speed and performance. However, even a diesel engine only needs a certain amount of oil on a regular basis. If your diesel engine is consuming oil at capacity, this is a sign that something is wrong.
As with conventional engines, excess oil consumption in a diesel engine is usually caused by a leak somewhere in the casing or components, allowing oil to escape from the engine to places it's not supposed to be. Not only is it expensive to constantly top up the oil, but it can also be a sign of failure or wear at various points.
Noticeable evaporation
Do you know how engine pistons use the air and fuel mixture to ignite a fire and push it down? Sometimes, due to the lack of a tight seal in the cylinder, some of the air-fuel mixture can pass through the piston and escape into the crankcase. This can result in a characteristic gurgling sound from the engine.
However, if the cylinders, piston rings, or crankcase are all wearing out at the same time, there will be a lot of smoke coming out of the engine at the same time, which is not safe or healthy for anyone nearby.
Colorful smoke
You would never want to see any kind of smoke coming out of your diesel engine. Even in movies, a stream of smoke coming out from under the hood of a car is a sure sign that something bad is about to happen. It would be bad enough if the smoke was white or black, indicating a fuel handling or combustion problem, respectively, but the big red flag to be concerned about is whether the smoke has a distinct blue color.
If your diesel engine is smoking blue, this is a sign that it is burning its oil supply as well as diesel fuel, possibly due to oil residue building up on the cylinder walls. This may be the result of an increased amount of oil in the engine, as well as deformations of the piston rings, valves or cylinders.
Loss of strength
One of the great attractions of diesel engines is the fact that their power is generally greater than that of a conventional engine. However, over time, this effectiveness may begin to slowly decrease. This is a common feature of an old, outdated diesel engine. Although the problem can also appear in newer engines under the right (or rather, wrong) conditions.
The key to a diesel engine's outstanding power is fuel quality. Diesel fuel can contain various impurities and debris, more so than regular gasoline, which may prevent normal engine functions. Normally, these impurities are filtered out by the fuel filter, but if the filter is clogged or damaged, all that loose dirt ends up entering the engine and unbalancing the entire process.