The engine is the heart of every vehicle, which is why it is so important to constantly take care of keeping it in good condition. Unfortunately, we sometimes forget about this, and in the meantime a great deal of dangerous deposits builds up inside it, among which carbon deposits deserve particular attention. What are they and where do they come from? What are the symptoms of their presence in a petrol or diesel engine? Learn the most important facts about this deposit and see that it is a real problem for your powertrain. Enjoy the read.
What are engine carbon deposits?
What are carbon deposits? The simplest way to put it is that they are the “silent killer” of the engine. They are a hard deposit, most often white or greenish-yellow in colour. They settle on the walls of the combustion chamber as well as on the engine pistons (in the case of both petrol and diesel engines). They sometimes also appear on the spark plugs, posing a risk arising from self-ignition. They bring with them many dangers to the powertrain - especially when they accumulate in excess. No matter what engine you have - petrol, diesel, naturally aspirated or turbocharged - one thing is certain: you can be sure that, sooner or later, carbon deposits will form inside it.
Engine carbon deposits - how do they form? There can be many causes
Where do carbon deposits in the engine come from? It depends on several factors, as well as on the type of design.
Carbon deposits in an indirect-injection engine are most often the result of combustion of the air-fuel mixture. This all happens in the combustion chamber - that is where the oil coking occurs, the result of which is precisely carbon deposits.
As for carbon deposits in a direct fuel injection engine, there the problem arises from the way the mixture is delivered. Instead of washing over the intake valves, the petrol enters the chamber directly, which causes deposits to accumulate on the valves. This in turn leads to the problem we described above, namely improper combustion of the mixture.
The carbon deposits that appear on the engine are also the result of a completely different way of operating the vehicle than even a dozen or so years ago. Other causes of deposit formation include:
- driving over short distances (running cold),
- extended oil service intervals (including Long Life servicing); old oil loses its protective properties,
- using low engine speeds (mainly in the case of turbocharged engines),
- improper operation of the timing tensioner (leading to irregularities in the combustion of the mixture),
- poor-quality fuel and engine oils.
You will find more information on this subject in the article entitled How do carbon deposits form? What can be the cause?
Carbon deposits on the engine - symptoms
How can you tell that there may be a considerable amount of carbon deposits in the engine? The main symptoms include:
- uneven engine operation,
- incorrect exhaust gas composition,
- higher fuel consumption,
- loss of power,
- errors appearing during the operation of the lambda sensor,
- problems with the ignition system, including misfiring spark plugs.
Types of carbon deposits in the engine
Carbon deposits in a petrol or diesel engine can occur in several forms. They are the result of various factors, including overly long intervals, oil burning or the presence of acid in the engine oil. The main types of deposit include:
- hard carbon deposits,
- soft carbon deposits,
- carbon deposits in the form of a so-called golden coating.
Carbon deposits in diesel and petrol engines - what dangers do they pose to the powertrain?
It can be said that carbon deposit build-up is one of the bigger problems that modern combustion engines have to contend with. Its excess can lead to serious, costly faults and breakdowns - and no driver wants that. That is why it is very important for each of us to bear in mind that contaminants in the form of carbon deposits or other deposits are not a myth, and downplaying them can cause us a great deal of trouble. What kind?
In short, it can be said that the presence of carbon deposits on individual engine components leads to a shortened service life of the powertrain - this is the result of increased friction (carbon deposits form a coating through which components wear away more easily). Due to their harmful action, components such as the following wear out faster:
- intake manifold,
- exhaust manifold,
- engine valves,
- EGR valve,
- turbocharger,
- DPF,
- catalytic converter,
- swirl flaps,
- cylinder liners.
The consequences of carbon deposit build-up - they can be costly
The moment one of the components listed above gets damaged, we can be sure of one thing: costs await us - especially when we are talking about repairing a turbocharger, gearbox bearings, the clutch or a dual-mass flywheel. Carbon deposits lingering in the engine can disrupt the operation of the entire system and effectively immobilise the vehicle - this in turn is often associated with ordering a tow truck (the costs can be substantial), followed by a costly repair.
Engine maintenance and carbon deposits - be sure to think about this
Owning a car is no great feat - the real challenge is keeping it in impeccable condition. In this case, great attention should be focused on the engine, because without it there can be no question of carefree driving. You already know that carbon deposits are a deposit that must absolutely be fought, although it is in fact practically impossible to get rid of them completely - over time, and as a result of the causes described above, they will eventually form again and settle on the various engine subassemblies.
It is important, however, to regularly remove their excess. How? The basis here is choosing a high-quality engine oil - preferably synthetic, which exhibits good protective properties for the engine, including, among other things, in dealing with contaminants.
Staying on the subject of engine oil, we must not forget about regular oil servicing. After all, when the old oil is drained, deposits, including carbon deposits, are flushed out.
It is worth enhancing the oil change with an engine flush - preferably using a high-quality engine flush, that is, a product created mainly for the purpose of eliminating carbon deposits and other deposits from the powertrain.
Engine flushing - is it safe?
Read more on our blog about dealing with carbon deposits in the article entitled Cleaning carbon deposits from the engine - how to do it?
For how deposits and carbon affect the cylinder wall, and what can still be cleaned versus what cannot, see our guide to the engine cylinder.
