When a blue black smoke is seen from the exhaust pipe, it signifies that the lubrication oil is entering the combustion chamber. Where there is a mixture of oil and diesel, the result of the combustion is the blue-black smoke.

One of the ways in which oil can enter the combustion chamber is a situation when we have a burnt top cylinder gasket. The job of the gasket is to prevent contact between the top cylinder and the engine block. It also stands as a barrier that prevents the oil that lubricates the rocker arms activities from entering the combustion chamber. So when this gasket burns, its duties fail and thereby leading to three things, oil entering into the combustion chamber, shortage of oil and overheating as a result of the contact.

Excess gauging of the oil in the sump can also cause the oil from entering into the combustion chamber because the oil scrapper ring will not be able to scrap the oil effectively.

Solution:  The solution to a blue-black smoke is first check for the burnt top gasket which will also be accompanied with signs like over heating. When this gasket is located then it has to be changed completely. The second which is the ring will also be accompanied with the loss of compression on the part of the engine. This means that the engine will no longer be giving out the required output. This is to say the ring is now worn out and needs replacement of the liner has expanded. Normally blue-black smoke fault arising from the rings comes from engines that are due for general overhauling. It is during overhauling that a wider ring will be used.