Smoke coming out of the exhaust pipe can be a warning sign of a serious fault. In this article we will discuss what a given colour of smoke means in the context of your car’s condition. Thanks to this you won’t be caught off guard and you will take the right steps faster to eliminate the fault.
Blue smoke
If blue smoke is coming out of the exhaust pipe, it means that the engine is burning oil that is making its way into its chambers. Unfortunately, diagnosing this problem is complicated and there is essentially no way to do it on your own. If the smoke only rises for a moment after starting the engine, it is possible that you have a problem with leaking valve stem seals. Blue smoke can also indicate worn piston rings. Replacing these components is costly, because it requires dismantling the entire unit.
White smoke
White clouds of smoke do not always have to be a warning sign of impending trouble. In winter it may just be water vapour that has accumulated in the exhaust system. If, however, your problem is not ordinary vapour, it means that water is getting into the combustion chamber, the cause of which is most often a damaged head gasket or the EGR cooler.
Black smoke
Black smoke coming out of the exhaust pipe in diesel engines is a completely natural phenomenon, as long as it lasts for a few seconds. Otherwise, the blame should be placed on accumulated soot, carbon deposits or a malfunctioning EGR. Determining the exact cause requires a professional eye and experience in car repair. So go to a mechanic who will help you find the cause of the black clouds of smoke.
Grey smoke
Grey-coloured exhaust fumes have the same basis as black smoke. The most common problem is excessively large fuel doses, which as a result leads to the appearance of black exhaust fumes.
A scored cylinder and smoking
Smoking can also be caused by problems with a cylinder on which scratches have appeared. You will recognise the improper operation of this component by:
- a drop in engine power,
- exhaust fumes coming out of the oil filler,
- a hissing sound in the crankcase,
- low compression pressure in one or several cylinders.
A damaged cylinder - can it be repaired on your own?
Unfortunately it is not possible to repair damaged cylinders on your own - honing under home conditions can only achieve a slightly better appearance and slightly shorten the break-in period. This method must therefore not be regarded as a method of restoring the proper condition or of repair.
On our own we can only prepare the engine block before the machining carried out by a specialist workshop. The repair must be performed very precisely according to the catalogue specifications, so that it is possible to select new pistons and rings that will operate optimally.
How to repair a scored cylinder?
The basic repair consists of replacing the liners or honing the scored cylinders. The cavities should not be filled with tin, because it can seize up the entire piston. Cylinder honing requires precision, equipment and experience. Such an operation can therefore only be undertaken by a professional workshop specialised in carrying out such tasks. If you care about restoring the cylinders to perfect quality, you should report to a trusted mechanic as soon as possible.
