Tag Archives: egr cleaning

Carbon Cleaners, Fuel Addtives, Fuel System Cleaning

Fuel & Carbon Cleaners – What Happens to the Carbon?

March 10, 2015 Oilem 2 Comments

Frequently we are asked about fuel-based carbon cleaners. Specifically, what happens to carbon deposits that are removed through the use of fuel cleaners and can these cleaners damage an engine?

Let’s begin by discussing the first part of that question.

Within the fuel system you’ll seldom find carbon itself. You are more likely to discover sludge, gum, varnish, debris, and similar deposits. The larger deposits are captured by the fuel filter. These and other deposits that have found their way through the fuel system are normally dissolved and dispersed in a controlled and manageable way using dispersal-based detergents. That’s why it is important to use additives at the recommended dosage so that deposit removal is completed in a controlled manner. High-strength fuel system cleaners that carry out this process normally contain a lubricant to ensure the entire system is lubricated during the cleaning procedure. This too minimizes the risk of any issues.

Most actual carbon formation occurs in the combustion chamber and post combustion areas. This includes the hot side of the turbo, intake, inlet valves, EGR, catalytic convertor, DPF, and the remainder of the exhaust tract. The reason why carbon remains is because there is insufficient heat to burn it off. Chemically, a liquid hydrocarbon fuel – such as gasoline or diesel – is very similar to the solidified fuel (carbon) that it creates. The difference is that to ignite and burn solid carbons a higher temperature must be reached because the flash point has changed.

High-quality fuel detergents, combined with fuel catalyst technology, reduce the threshold temperature at which the carbons can burn and therefore enable natural engine processes and inherent heat to gradually “burn off” the deposits. This is certainly the case for combustion chamber deposits.

Sometimes there also is a degree of active cleaning from any cleaning chemistry that is able to survive the combustion process and thus is still active post combustion. However, most carbon is removed by reducing the temperature at which it can burn as described above.

It is important to note that there also is a natural cleaning mechanism. When the combustion process is of sufficient quality – normally through an efficient fuel system (no injector deposits), sufficient fuel quality (more often than not, only achieved with fuel conditioners), and an engine that is up to full operating temperature – engines are designed to self-manage carbon build-up. The clean(ish) gases will naturally remove carbons with the aim of maintaining a respectable level.

The issue arises when this equilibrium is broken and more carbons are deposited than can be naturally removed. This could be due to a flawed engine design, poor fuel quality, fuel system deposits, driving style, failure to let the engine get up to the proper temperature, etc., or a combination of these.

This is why catalyst technology is so important in carbon cleaning and for keeping a system clean. When a catalyst is added to the fuel, it improves the quality of combustion to such a degree that it reduces the amount of hydrocarbons that are created, particularly when the engine is cold. These cleaner gases then get to work together, with the active work the catalyst is doing, to reduce the temperature at which these deposits can burn and be removed.

Essentially, a high-end fuel cleaner and carbon remover provides an environment where the quality of the combustion is much better and the exhaust gasses are much cleaner. The cleaner exhaust gasses will naturally scavenge and remove carbons from the combustion and the post combustion areas. The caveat is that this process requires heat. The catalyst will reduce the temperature at which the carbons can be removed and burned off, but it also needs heat.

This is why it is incredibly difficult for such chemistries to clean the EGR system. The problem is that an EGR and intake are designed to cool recirculating exhaust gasses. By doing so, they reduce the efficacy of any post combustion cleaner or chemistry. Unfortunately this also applies to the rear of the intake valves of direct poor injection engines. Those two areas are very difficult to clean because the gasses going through are cooled.

Also it is difficult to remove existing deposits in these areas. However, by using a high-quality conditioner with the fuel catalyst in both diesel and petrol applications, you’ll at least give the engine and emission control components a much easier life. This is because the engine and emissions systems will have fewer carbons to manage. This results in fewer deposits and hopefully removes the need to use high-strength cleaners or invasive measures to remove carbons manually.

What about the safety of cleaners and the risk of fuel system or engine damage?

Providing products are used as per the instructions, the risk of any damage is incredibly low. In fact, the few rare cases of alleged damage we have seen weren’t actually caused by the product. The product just revealed or exacerbated an underlying mechanical issue with the fuel system. This is incredibly rare.

Furthermore, manufactures err on the side of caution, so even if a product is used aggressively or improperly, it is still likely to be safe to use up until a certain point. For example, one of our main fuel conditioners is EPA tested. As part of the procedure the product is tested at ten times the recommended dose to ensure no possible harm to the fuel system or engine.

To summarise, fuel system deposits are generally dissolved, dispersed, and combusted naturally. Carbon is generally combusted through the use of heat and an added fuel catalyst and/or fuel borne catalyst. They are proven safe processes when used correctly and responsibly.

Carbon Cleaners, EGR Cleaning & Maintenance

Importance of a Clean EGR

August 21, 2013 Oilem Leave a comment

The subject of EGR (Exhaust Gas Recirculation) systems comes up often so I thought it was about time we explained further on how a dirty EGR can effect performance, MPG and exhaust emissions.
With our professional range of cleaners we are confident that we can resolve a large percentage of the minor poor running issues (hesitation, poor idle, reduced performance, MPG, increased exhaust smoke etc) that our customers encounter. So where does that leave the other percentage? From our experience, faulty EGR’s (due to deposit accumulation) and faulty sensors (the Mass Airflow being the most common) contribute to a large proportion of running issues that professional fuel injector cleaners won’t resolve.

What is an EGR valve?

An EGR valve, or exhaust gas recirculation system is a primary component of an engine’s emissions system on both petrol and diesel powered vehicles. Its purpose is to reduce NOx emissions by recycling a proportion of the combustion gases that normally exit through the exhaust. Recirculating some of the spent exhaust gases back into the engine is one way to reduce these harmful emissions, and this is done by way of an Exhaust Recirculation System (EGR). The main component of this system is a valve that essentially returns a proportion of the exhaust gases back into the engine to be mixed with clean air, fuel and then re-combusted.

The gas to be recirculated can be passed through an air or water type EGR Cooler. This in turn reduces the temperature of the gas, which reduces the charge temperature that leads to an improved quality of combustion and engine power. In the case of a diesel engine, the recirculated proportion of gases can sometimes be as high as 50% under certain operating conditions.

Over time the EGR valve and associated pipework accumulate carbon deposits. These inhibit bypassed exhaust gasses back into the intake and play havoc with the fuelling and thus we end up with hesitation, reduced MPG and ironically, excessive emissions, particularly when the EGR is transitioning from open to close and vice versa. Unfortunately modern electronics do not always recognise a faulty EGR except when flow is fully impeded or there is an electronic fault with the control solenoid/actuator. What happens is that carbon builds up on the EGR valve itself creating a resistance to the opening and closing of the valve. Basically, this vacuum operated valve sticks and the solenoid that operates the vacuum has to work overtime to create sufficient vacuum to open the valve. An excess draw of current then trips the ECU warning light.

Carbon build-up cannot be avoided fully as there is a natural and strong affinity between hydrocarbons and metal surfaces. The key is to maintain a manageable level of carbon build-up within the system and in quantities that the engine can naturally consume.

It is important to understand why carbon builds up in the first place and where it comes from. Contrary to popular believe, carbon build-up comes not just from fuel but also from the engine oil. Engine oil can bypass engine rings, inlets valves and crankcase breather systems and then polymerise on intake and emission control system components as its recirculated. This creates a porous surface from which further oil vapour and then also excess hydrocarbons produced from the combustion process can then adhere and create further build-up.

There are numerous solutions now available ranging from aerosol sprays with accompanying fuel cleaner to pressurised detergents that are atomised into the intake and EGR system. The most effective way is a manual clean of the EGR valve and periphery pipework but this is not always possible without significant labour time. It is also important to note that it is not always the valve that blocks up but the pipe leading from the EGR back into the intake. The hole(s) where it leads into the intake are normally very small and can block up very easily. This then backs up to the valve.

Why do fuel cleaners struggle with EGR cleaning?

Fuel cleaning technology has come on a long way and carbon can be removed from most areas of an engine and emissions control system though fuel system cleaners. However, EGR’s are notoriously difficult with this method. Here’s why:

There are 4 types of fuel based EGR cleaners (1st 3 are added to the fuel).

1. Low-cost solvent based cleaners that do very little other than clean the fuel injectors as the chemistry is destroyed during the combustion process.

2. Higher quality fuel system cleaners that use chemistries such as polyether amines to help remove combustion and post combustion deposits, although most of it Is destroyed during the combustion process.

3. Patented molecules that are activated during the combustion process (rather than destroyed) and are then carried in the recirculating gases. These molecules bond with the carbon acting as a catalyst for its removal.

4. Solvent cleaners that are sprayed into the air intake and circulate through the intake system, EGR, combustion area and out into the post combustion areas including the turbo and EGR again.

Product type 1 is useless. Product type 2 may have some effect if the carbons are mainly fuel related, but this process relies on heat. What happens is that such products improve the quality of the combustion to the degree that the cleaner exhaust gases will naturally scavenge and remove carbon from post combustion areas. This is more workable in areas such as the turbo, DPF, CAT etc as heat is maintained. This cleaning mechanism is effective with HOT, clean exhaust gases but an EGR system is designed to cool the gases so the efficacy is reduced considerably. Furthermore, there has to be sufficient flow through the EGR system for this process to work. If it is blocked completely then natural scavenging will not work.

On a side note, fuel additive manufactures have been careful not to reveal the fact that combustion modification and improvement and the resulting cleaner exhaust gases can naturally remove carbon deposits! I remember one of our long term test vehicles (Audi S8 4.2 TDI) having exhaust tips cleaner on the inside than on the outside and I’m not kidding.

Product type 3 is similar to 2 and slightly more effective. Specific molecules in the fuel additive are dormant and become active during the combustion process. Carried through the recirculating exhaust gases they bond to carbonaceous deposits. This acts as a catalyst to dissolve/remove the deposits to the combustion area where they are then burned. However, just like with product type 2, this method requires sufficient heat and airflow through the EGR system.

Product type 4 is the most effective as the solvents do not require heat to work and and hit the target areas more easily. Again, if there is substantial oil build-up then it is much more difficult to remove.

For information on products to clean the EGR system and keep it clean, read our article HERE.

EGR Cleaning & Maintenance

EGR Cleaning and EGR Cleaners

July 29, 2013 Oilem 51 Comments

An EGR valve, or exhaust gas recirculation system is a primary component of an engine’s emissions system on both petrol and diesel powered vehicles. Its purpose is to reduce NOx emissions by recycling a proportion of the combustion gases that normally exit through the exhaust. A valve is used to control the flow of gases, which are re-routed through the intake system, where they are re-combusted with fresh intake air and fuel. On a correctly functioning EGR system, this lowers undesirable exhaust emissions.

The problem with these systems, particularly with diesel vehicles, is that excess hydrocarbons are produced during the combustion process. These hydrocarbons deposit themselves on the EGR valve and periphery pipe work where the EGR routes back into the intake system. Over time, this clogs and eventually blocks the EGR valve and the associated pipework.

Additional Source of Deposit Build-up!

It is important to note that the carbon buildup you see in an EGR system and other emission control components is not only from the combustion process. In most cases, it’s a combination of combustion-produced hydrocarbons and also carbons and deposits from the crankcase oil. This is where many fail to correctly arrest deposit build-up on the EGR after it has been cleaned or replaced. More on this later…

What happens is engine oil can bypass the piston rings, valve stem seals and crankcase breather system (PCV). That oil is then consumed during the combustion process, but it isn’t fully combusted. The unburned oil and fuel are both recycled and deposited within the EGR. The oil in particular will polymerize onto the metal surfaces due to the very strong affinity between oil and metal. This newly formed surface then acts as a “sponge” for all further particulates in the recirculating exhaust gases.

Basically, what you have is a combination of bypassed oil and unburned fuel deposited within the EGR system. This turns into a solid, which builds up and clogs the EGR valve and associated pipework, causing faulty operation.

If the EGR valve begins to stick or is blocked up, the solenoid used to operate it will draw more current to open it. The ECU detects that condition and throws an engine warning light.

The symptoms of a faulty EGR include:

Hesitation
Stumbling
Excessive emissions/smoke during acceleration
Engine warning lights

As deposits begin to accumulate this restricts the flow of gases and disturbs the fuel mixture. The ECU is expecting a certain amount of recirculating gases as the EGR valve transitions from closed to open and visa-versa. These gases are not delivered as anticipated hence the disturbance in the air/fuel ratio. This can result in hesitation, stumbling and excess emissions, particularly during acceleration.
Natural Carbon Removal

Now, there is a natural cleaning mechanism for carbon and most additive manufacturers won’t tell you this. If you’re able to improve the quality of combustion, and are thus able to produce cleaner exhaust gases during the combustion process, these cleaner exhaust gases will naturally scavenge and remove carbon. This is also the case with many emission control components attached to the exhaust system, such as the hot side of the turbocharger, catalytic converter, or a diesel particulate filter.

You can naturally clean these areas. Many additives you see on the market today are essentially just fuel system cleaners and combustion catalysts. They might be promoted and marketed as EGR cleaners, DPF cleaners and so on, but they’re really nothing more than fuel system cleaners. What they do is restore the efficiency of the fuel system and by doing so, improve the efficiency of the combustion, which reduces hydrocarbon production. In addition, some products contain a fuel catalyst technology that in itself will lower the hydrocarbons produced. What you’re left with is cleaner exhaust gases, which will help naturally remove the carbon from these mentioned areas. Except for a very few products that contain patented technologies where molecules are activated during combustion (more on this later), such cleaners do not directly clean these areas, as the chemistry is destroyed during the combustion process.

The Problem with Natural Removal and EGR Valves

Now, this natural cleaning mechanism is not always effective when cleaning the EGR system. The reason for this is that when cleaning carbon from your engine, heat is the primary factor. It is important that there is sufficient heat. Heat, combined with the cleaner, recycled exhaust gases, helps remove carbon. The problem with the EGR is that the gases are usually cooled by the time they reach the valve and the periphery pipework. Therefore, the natural cleaning mechanism is not always as effective with EGRs, so you have to take alternative action.

Alternative Cleaning for EGR Valves and Systems

Unfortunately, the most effective way to clean an EGR is to remove it and clean it manually (if you have access to it). You’ll remove the EGR and the periphery pipework. Scrape off as much carbon as you can manually, then use a quality EGR aerosol cleaner such as Ecotec Soot Cleaner Aerosol, to clean the remainder and reassemble the system.

If you don’t have easy access to the EGR valve, you can use an in situ aerosol-based EGR cleaner that you can either spray into the EGR pipework or through the air intake and clean the EGR this way. However, particularly with diesel engines, you must be very careful. You don’t want to damage the engine. If you’re in doubt, you should let a trained professional carry out this procedure for you. For this we recommend the Ecotec Turbo Net and EGR Cleaner Aerosol.

Once the EGR is clean and operational it is important to take the steps necessary to prevent further carbon buildup. While you can never stop it completely, what you can do is maintain a manageable level of carbon that the engine can naturally consume without the deposits becoming excessive. If you were to remove the EGR, what you’d be looking for is a very fine layer of carbon that you can scratch off with your nail. Anything more than that would be considered excessive.

Maintain and Protect

1. Firstly, use a high quality polyetheramine-based fuel system cleaner and carbon remover to ensure injector and combustion efficiency is restored. Otherwise, you’ll end up with a clogged EGR valve soon after. For this we recommend Archoil AR6400 or AR6400-D MAX for diesel engines.

2. Secondly, you need a VERY high quality engine oil and/or oil additive that helps prevent oil bypassing the crankcase breather system or piston rings and polymerizing with the EGR system. You must tackle the problem from both the fuel system end and also the crankcase oil. For this I would recommend the Bardahl C60 fullerene range of engine oils as the advanced nano additive pack has proven to keep the EGR and similar systems clean. Alternatively use a high quality oil additive pack such as Archoil AR9100 or AR2300. These have shown to prevent polymerisation and even remove carbon from these areas in some cases.

3. Thirdly, and particularly if the majority of your driving is short or start/stop, use a high quality ongoing fuel additive containing an effective combustion modifier or fuel catalyst. For this we recommend Archoil AR6200 (petrol) or AR6900-D MAX (diesel). What this will do is improve the quality of the combustion and lower the amount of hydrocarbons being produced and thus recycled through the system, especially when the engine is in its warm-up cycle. Most of the time you’ll only use a little bit of the product at a time and a single bottle will last for multiple tanks of fuel.

Get Out and Drive

Finally, it’s important to make you aware our view is that most of today’s vehicles are commonly mis-sold. They are simply not designed for the short journeys that many people use them for – around town driving, shopping runs, school runs, etc. If the vehicle is not permitted to get up to temperature on a frequent basis, it’s inevitable that hydrocarbons will be produced and deposited throughout the system.

Because of the lack of heat, it will be very difficult for the engine and the emissions control components to naturally manage carbon within the system. Therefore, using the correct types of oil, fuel and fuel additives is essential to keeping the engine running efficiently.

If you require any expert advice or help then please don’t hesitate to contact us and either I or a member of my team will be pleased to help.

For rapid fuel system cleaning

AR6400 (petrol) or AR6400-D (diesel)

Fuel conditioning, protection and carbon reduction

Hybrogen or AR6900-D MAX

Nano oil additive pack to reduce circulating oil build-up in the EGR

AR9100