Articles of Interest for Repair Professionals

Re-printed from The Profit Report 2/07

Fuel and Oil Deposits Are Often Inter-Related

Chicago, IL February 2007 – The cleaning of both an engine’s fuel side and oil system have increasingly become clouded in confusion and uncertainty for OEMs, service writers, technicians and customers. The problems largely stem from tunnel vision on symptoms, unwillingness to admit to engine design factors and a tendency towards the quickest and cheapest available service.

Fuel and Oil Deposits Are Interrelated
The fact that fuel system issues impact oil system deposits and oil system issues affect fuel system deposits seems to be one of the least communicated or accepted facts around these issues. Not accepting this fact seems to account for much of the misdirected “cleaning” efforts in the market.

First we should define what is meant by fuel system deposits. Fuel system deposits will be defined as deposits that cause loss of performance, mileage, drivability, or decrease in service life of components in the following areas:
· Throttle body and idle air control
· Positive crankcase ventilation (PCV valve and hose
· Intake and valves
· Fuel injectors
· Exhaust gas re-circulation (EGR) valve
· Top of piston
· Oxygen sensors
· Catalytic converter

Two components in this list are not truly “fuel system” components. The catalytic converter is part of the emission control systems but it is directly impacted by loss of fuel control.

The PCV system is designed to function as a system to protect the oil system from gasoline and water contamination and to provide emissions reductions. It has been included in the fuel system for this list because the PCV system is the preferred service port for induction fuel cleaning services.

Oil system deposits will be defined as deposits on the following components that cause a loss of oil control, excess oil consumption, insufficient lubrication and mechanical wear:
· Piston rings
· Oil galleys
· PCV

Now that we understand the location of deposits that cause problems, it is important to know why deposits end up on those locations and cause problems.

Causes of Fuel System Deposits

The first factor that must be established is that the burning of gasoline causes deposits and all gasoline engines will develop them. The marketing folks at Honda and some other OEMs (in a blatant and somewhat comical effort to artificially lower their cost of ownership calculations) will argue this point, but no gasoline engine has 100% burn of the available fuel. Even efficient and clean engine designs will not remain so under all operating conditions, maintenance levels, or levels of fuel quality, so they will all build deposits.

Beyond this, fuel system deposit levels are the result of the following factors:

· Fuel quality used
· Fuel additives used
· Driving patterns
· Levels of maintenance performed
· Degree of tune
· Operation of the oxygen sensor
· Valve guide and seal condition
· Engine and related component design

A quick look at the list reveals that 6 of the 7 factors listed are completely or somewhat controlled by the vehicle’s owner. This is why when problems occur, the initial default position of dealerships and OEM is that it is the owner’s fault, not theirs.

Causes of Oil System Deposits

Sludge is becoming a dirty word in the automobile business. Toyota, Volkswagen, Audi, Saab, Nissan, Chrysler, and Mercedes-Benz have all had sludge problems recently on their engines. Cadillac, Saturn and others have had oil control problems on their engine designs.

The key issues affecting oil system deposits are:

· Oil quality used
· Quality of air and oil filters
· Frequency of oil changes
· Driving patterns
· Gasoline additives
· PCV system design
· External heat sources near the oil sump
Again most of these factors are controlled by the vehicle owner so the default position of dealerships and OEMs is that problems stem from the customer’s maintenance habits.

Problems Cascade

Before examining the list of causes and recommended solutions another important point needs to be made clear. No deposits form in isolation, and once a problem causes symptoms in one area, you can know with assurance that other components have been compromised.

Trying to quick fix a problem with a targeted cleaning of the area causing the symptoms is quite likely to be ineffective or at best to have short-term benefits.

Problems in one system will almost always cascade into problems in another.

A Typical Story of Deposit Formation

As mentioned previously, all vehicles will develop fuel system deposits. This illustration is provided as a very typical story of the development of deposits in a Chicago area vehicle.

Sam was very proud of his new Honda. One of the best rated vehicles on the road.

Sam made sure to always use the fuel recommended by the carmaker whenever possible. Unfortunately that became more infrequent as it seemed that the station selling that type of fuel was always “overcharging” for its fuel by 2 – 4 cents per gallon.

To keep the fine corn farmers of Illinois happy the folks in Springfield and Washington provided lots of subsidies for ethanol. Sam’s car didn’t particularly like ethanol above 5%, but ethanol levels of 10% were common and sometimes exceeded that in the ground at the station.

Even though he was driving a peppy driving machine Sam rarely got above 30 mph in his bumper to bumper commute. His other trips were often short around town jaunts when the engine barely warmed up.

It always seemed like a hassle to find a place to get an oil change downtown and the last thing he wanted to do on a Saturday was to drop by the dealership for an oil change. The oil got changed regularly, but maybe not as regularly as the carmaker had recommended (and they were now recommending oil changes at much longer intervals than Sam remembered when he bought his first car 20 years ago).

Air filter changes and PCV valve changes weren’t quite at the top of his mind.

Soon the poor quality of fuel and high levels of ethanol started to cause some dirty deposits to form on his pistons and intake valves.

Pretty soon the knock sensor in his car was noticing a slight problem with the detonation within a couple of the cylinders. The car’s computer adjusted the timing to correct the problem and the car was allowed to run slightly richer to make sure that Sam’s engine didn’t feel too rough. The fuel was then less efficiently burned leading to more combustion chamber deposits, which lead to further changes to timing, which lead to more deposits, less power and poorer fuel economy and so on.

The change was very gradual so Sam didn’t really notice a big change in performance and fuel economy but they steadily dropped month after month.

The higher levels of ethanol in the fuel were being carried by the “blow by” of exhaust gases passed the rings into the oil system. The ethanol contributed to the breakdown of the oil in Sam’s car. The phosphorous in the oil was vaporized and sent by the PCV valve to the air intake, through the engine and onto the oxygen sensor and catalytic converter, impairing their performance.

The ethanol was also very slowly breaking down the surfaces of the plastic and rubber parts that it passed over from the gas tank through to the injectors. These plastic and rubber elements caused injector deposits and intake valve deposits that then provided a base for more deposits.

The injector spray pattern became inefficient and the valve deposits started to impact his idle, cold temperature performance and performance at higher engine load.

The oxygen sensor was now receiving too much fuel from a rich condition caused by the retarded timing, and was being coated with phosphorous. As a result it started to become lazy and was no longer sending information for the correction of the air-fuel mixture to the car’s computer fast enough. As a result combustion became even more inefficient and deposits built faster.

The catalytic converter was also coated with fuel and phosphorous and began to work less efficiently. The less it worked, the faster that it deteriorated.

The PCV valve became more and more plugged with deposits. Soon the engine was not expelling the gas and water vapors from the crankcase and the engine’s oil began to breakdown into sludge. The sludge restricted the lubrication of the engine and it began to run hotter.

The oil was no longer able to suspend debris so oil galleys became clogged.

Two of the runners for the EGR system on his car were longer than those for the other 4 cylinders, so the temperature dropped for the gases in those cylinders and deposits formed. Soon those cylinders were receiving less re-circulated exhaust gas and ran hotter, and richer. The car’s computer again tried to adjust timing and fuel to compensate with negative impact on fuel economy, drivability and performance.

Sam’s once peppy, fuel mileage king is now an underpowered, ,rough running, lower mileage vehicle with excessive, if still unseen engine wear.

He brought his car to the Honda dealer and was told that the marketing people of Honda had determined that Honda’s fuel system does not need to be cleaned. What was Sam to do?

This story is not some wild confluence of events or worst case scenario. This is the real world faced by drivers in Illinois.

What Are the Solutions?

The first solution is for technicians and service writers to understand the variety of factors that are impacting deposits in an engine in Chicago. In 3 minutes or less they should be able to communicate this to a customer so that their customers understand that every vehicle in Chicago (not just those towing trailers) is a severe service vehicle.

There also needs to be a better understanding of vulnerabilities specific to any engine design. An engine design is a balancing act of dozens of design parameters to achieve power, efficiency, low noise levels, low emissions, fit into a specified compartment space, at a low weight, for prolonged durability, at a low cost of ownership and with minimum cost of manufacture.

No car company can optimize all of these variables. Every engine will perform as advertised for a long period of time under ideal conditions. Conditions cease to be ideal within 2 blocks of leaving the dealership, and writers and technicians should know the vulnerabilities of the engine.

As an example, GM and Chrysler have had injector tip designs that were more sensitive to injector tip deposits. Volkswagen’s steep V6 engine design (“inline V”) is more sensitive to intake valve deposits, and is harder on oil. Honda’s older 2.2 liter engines have been susceptible to EGR deposits. Mercedes and BMW have been sensitive to piston carbon deposits. The Chrysler 2.7 l, Toyota’s V6 and inline 4, VW’s 4&6 cylinder engines, Subaru’s flat engine, Saab’s inline engine, and Nissan’s 2.5l all have known sludge problems.

If the engine design has a very fine injector design that is more vulnerable to deposits, make sure the customer knows to clean the injectors regularly. If the car has multiple, small valves that makes it vulnerable to valve deposits, then they should be regularly maintained. If the car was designed with a smaller than normal oil capacity, make sure they know not to try and extend the oil change interval without using oil additives.

If you use a one size fits all approach to selling fuel or oil services, you will waste customers’ money on areas that don’t need attention, decrease CSI, and leave them vulnerable to other problems.

It also needs to be emphasized that a solution should not come at the expense of a future problem. Too many times chemicals are thrown at poorly diagnosed “injector” or “intake” problems that then loosen carbon and sends the deposits and the chemical used onto the O2 sensors and cat. The most important fuel control component and the most expensive emission component are put at jeopardy for a “preventative maintenance” item.

This is the reason why customers think engine cleaning services are smoke and mirrors efforts to separate them from their money.

With knowledge of the problems faced in our region and for specific vehicles you then need to specify the best service for the specific problem area.

Throttle Body
The throttle body helps control the amount of air and fuel that enters the engine. Excess deposits on a throttle body will cause the throttle plate to “stick” or not open freely. This will be felt with a gas pedal that seems to stick, and with an irregular idle.

There are two methods of cleaning the throttle body: an induction cleaning, and a traditional throttle body cleaning.

With an induction service the throttle body and the intake of the vehicle receive a mist of a cleaning chemical that is “induced” into the air flow while the vehicle is running. The chemical is designed to turn carbon in a hard form into a soft form that can be moved by the engine pressure and gravity.

The second method that is used is for the technician to remove the air intake assembly to expose the throttle body, and then spray a special cleaning chemical into the throttle body, and on the throttle plate. With the vehicle running certain products such as Terraclean’s post-combustion cleaner and Well-Worth’s can be induced into the idle air control motor to clean it too.

The technician then uses a brush to remove the carbon and the cleaning fluid and a rag to wipe the area down.

The traditional throttle body cleaning service is preferred to an induction service. If an induction service is done, the technician should still go back after the service and wipe down the throttle body and the plate. This step is rarely done in many garages.

Air Intake
Excess deposits in the intake will cause noticeable deceases in performance and an increase in emissions. Evidence of intake valve deposits will include stumble and hesitation when cold. Severe carbon deposits will restrict airflow to the cylinder and can cause loss of power at high engine rpm.

On most vehicles intake manifold carbon does not cause any performance issues and moving it from its location chemically is more likely to compromise performance than it is to help. The “liquefied” carbon is then moved through the engine and on to the oxygen sensor and catalytic converter.

This is a service that should be performed if there is an indication of a problem, or as preventative maintenance on vehicles with a known sensitivity to intake carbon such as Volkswagen. This is a case of letting sleeping dogs lay.

The induction service is an oversold service in the market today. It is often sold because it is a “fuel system cleaning “ that requires fewer skills by the technician, and is fast and cheap to do. It is also one of the services that is most focused on by chemical distributors because of its profitability.

A choice has to be made in cleaning the intake valves between an induction service and a mechanical cleaning. Induction is by far more cost effective and is technically effective on many vehicles. In severe cases walnut shell blasting is sometimes necessary.

In the case of a chemical induction cleaning there is a consideration of the chemical formulation. There are chemicals to dissolve the hardest carbon, but they are not fully safe for many parts and coatings in the engine and emission system. There are also chemicals that by themselves create deposits that promote future carbon deposits.

There is always a potential for one problem to be solved but with other problems then being caused.

Well-Worth Products ProShock is a concentrated and targeted induction cleaner with no fillers. Products with excess fillers can be identified by the amount of smoke they produce. This product is very effective in removing intake deposits, and combustion deposits, and has been shown to have a positive impact on oxygen sensors and catalytic converters.

Uview Ultraviolet’s “Terraclean” fuel rail service has been shown to be very effective as the injectors direct the product at the back side of the valves. A combination fuel rail and induction service is the most effective solution for intake valve issues.

EGR Valve
As a means of reducing emissions of nitrous oxides, there is a valve in the engine that diverts gas exhausted after combustion in the engine, back to the air intake of the engine instead of out the tailpipe. This is referred to as an EGR.

Excess carbon will result in a “clogged EGR valve”. Depending on the engine design and the degree of the problem, an induction service may help address the problem and in some cases mechanical repair will be required.

The Well-Worth ProShock induction service when performed at slightly above 2,000 rpm will hit the EGR. A scan tool can also be used to open the EGR during the service to draw more cleaner through the system.

Fuel Injectors
Most drivers are familiar with the concept of “injector cleaning” products and services. Most people have seen the photo of the spray pattern of a dirty injector beside a photo of a clean one.

A clogged or restricted-flow injector will cause noticeable drivability problems, and the problem will likely cause an engine code. Most chemical companies will offer a polyetheramine formulation (Techron) for this problem but other lower cost formulations are in the market.

There are four options for cleaning injectors:
· a fuel rail service
· a “two line” flush service
· an in tank additive
· off-the-car ultrasonic cleaning.

In tank additives are obviously the cheapest to administer, but are less likely to produce consistent results, especially on an injector that is truly clogged. If an in tank product is used it should be a good polyetheramine formulation.

Off-the-car ultrasonic cleaning is the most effective solution, but is also the most expensive and in some cases it is preferable at that point to install a new injector.

Fuel rail services offer the best solution in virtually all cases, and some fuel rail systems offer technical effectiveness that approaches that of ultrasonic systems.

When choosing a chemical to administer through the fuel rail, it is again wise to focus on the chemical formulation and whether it is pre-mixed with fuel.
Many of the chemical formulations that have been used and continue to be used have been formulated to remove even the hardest deposits. As a result they are not always friendly to coated, plastic or rubber components, especially if not used in a properly diluted concentration.

These chemicals provide a risk to fuel pumps, fuel tanks, plastic injector tips and other components. Most of these systems will require the regulator to be disabled to prevent the chemical from getting to the gas tank.

Systems that require the tech to properly mix the chemical detergent or solvent with gasoline create an opportunity for recommended concentrations to be exceeded. Some techs brag about exceeding the recommendations to “really clean” a vehicle.

This is another area where the service is oversold as a preventative maintenance item. Chemically flushing injectors that are not causing a performance problem will loosen carbon and move it in a paste form through the engine and onto the oxygen sensor(s) and catalytic converter.

This will negatively impact their performance in the short term, possibly the long term, and the chemicals used can create deposits on those components.

There is not a good logic to this service since the oxygen sensor has a primary role to play in engine performance and fuel mileage and the catalytic converter is one of the most expensive components on the car.

Uview Ultraviolet’s Terraclean system is a noteworthy new development in this area. Documented by Linder Tech of Indianapolis to clean even zero flow injectors back to OEM specified flow rates, the system uses a pre-mixed formula that is made up of 96% of a proprietary, modified gasoline.

The system has an additional benefit of having a second step that cleans the pistons, oxygen sensor and catalytic converter of any deposits that might have been loosened.

Piston Carbon
All pistons will have some evidence of carbon in two forms. One form is a marble-hard form that is evident towards the center of the piston. This carbon does not affect engine performance.

The second type is a crystalline, sponge structure that will build around the outside of the piston and towards the center.

This form of carbon, once it has reached a certain point, will begin to soak fuel in it and cause mistimed combustion. This will result in poor idle quality, poor performance, and “dieseling” when the vehicle is shut off. These deposits can also create mechanical interference in the engine.

There are four approaches to this problem:
· a chemical can be used to cause the engine to run much hotter than normal to try and burn away these deposits
· a chemical can be introduced to try and soften the carbon to a form that will flow
· conditions can be created to provide excess oxygen in the engine to allow these deposits to burn themselves clean
· the carbon can be mechanically ground off

Elevating engine temperatures obviously comes with some risks. The engine’s cooling system is designed to compensate within a reasonable range, but excess heat will risk engine and sensor damage.

Changing carbon to a soft form creates deposits that end up on the O2 sensor and the cat.

Mechanically grinding the carbon requires the engine to be opened which is very costly to do.

The Terraclean system creates the conditions for excess oxygen to be provided that will combine with the potential fuel represented by the carbon and the heat to get the deposits to burn themselves clean. It also creates an exhaust stream that is wetter to help decoke the engine and post-combustion components.

The Terraclean method is highly effective, cost effective and probably the safest method of cleaning.

Oxygen Sensor and Catalytic Converter
Both the oxygen sensor and the catalytic converter will tend to fail over time because of deposits. The sources of deposits have traditionally been unburned fuel and additive, but with the introduction of ethanol into the fuel supply vapors from degraded oil are more common. Ethanol in the blow by causes the oil to breakdown with the phosphorous in the oil then carried as a vapor on to the O2 and cat.
These deposits cover the surfaces that read oxygen levels, for the oxygen sensor, and the precious metal catalysts in the cat.

Until the development of the Terraclean system there was no method proven effective by third parties for cleaning and maintaining these items. The Terraclean system has been reviewed by Linder Tech of Indianapolis, the British Columbia Institute of Technology, Speed Channel’s “Dream Car Garage”, McGill University and hundreds of garages for the effectiveness of the system on oxygen sensors and catalytic converters. The system has been demonstrated to be effective in creating performance improvements for oxygen sensors contaminated by fuel.

The oxygen sensor is the most important component for its impact on fuel mileage and performance. One study showed that a fuel mileage improvement of up to 40% was possible with a clean oxygen sensor. The catalytic converter is important for controlling emissions and is one of the most costly components to replace on a vehicle.

A contaminated oxygen sensor will begin to become “lazy”. The contaminants on its surface will cause it to respond more slowly. Less information to the car’s computer (ECM) will lead to more infrequent adjustments to the air-fuel ratio entering the engine. This will lead to poorer fuel control and this will likely lead to additional O2 and cat deposits.

In the logic of a modern vehicle’s computer, a compensation will be made for a “lazy” O2 by running a slightly richer air-fuel ratio and dialing back the timing of the engine for a period before an engine light is triggered.

The impact of this adjustment is a decrease in fuel mileage and a decrease in engine performance, and further deposits on the O2 and cat. Because the process is gradual, the impact is not noticed.

Because the eventual loss in mileage and performance is significant over time, the improvement from the cleaning is also nearly always significant to the vehicle’s owner.
Fuel mileage improvements of up to 18% have been documented and horsepower improvements of up to 6% were documented by “Dream Car Garage” on Speed Channel.

While the system is effective in cleaning these components, it is unlikely that heavily contaminated oxygen sensors or catalytic converters can be restored to a condition that will provide long term continued use.

In field trials Well-Worth’s ProShock product has also shown some benefits to oxygen sensor and catalytic converter efficiency. The combination of ProShock followed by Terraclean’s post-combustion cleaner seems to offer exceptional potential for this service area.

Oil System Cleaning
Oil system cleaning can be accomplished in one of three ways:
· Crankcase dump in product
· Engine on/dynamic oil flush system – RTI
· Engine off/static oil flush system – EnviroLution
This is an area of service that is somewhat controversial because of concerns about the impact on lubrication of the engine during or after the service.

“Engine on” systems like RTI’s OSX-2 introduce cleaner and oil to the vehicle’s oil system as the vehicle runs. The theory in this system is that more of the engine deposits are removed if oil and cleaner are being splashed around as the vehicle idles.

“Engine off” systems like EnviroLution’s inject a heated solution of oil and solvents through a pulse method to remove deposits.

Both systems will do a very good job in removing oil system deposits and sludge. After spending quite a bit of time on the Internet looking for complaints of engine failure after such a service none could be found. Such failures would cause loud complaints so it is safe to assume that they are very safe services.

The third method is to use an oil flush additive, like Well-Worth’s eFlush product, to the crankcase immediately prior to an oil change. The additive breaks up any deposits and sludge and allows them to be suspended in the oil and drained prior to the new oil being installed.

If oil sludge is a concern to the point that an oil system flush is recommended, then thought should be given to what this means for the fuel and emission system components.

The formation of sludge necessarily means that components of the oil while it was breaking down were vaporized. If they were vaporized, then by design the PCV system was purging them to the intake, and from the intake affecting components through the engine, passed the oxygen sensors and through the catalytic converter(s).

If the customer cannot afford a fuel system cleaning during the same visit then they need to be made aware that their vehicle’s performance, mileage and life of the components in their vehicle’s engine and emissions components have been compromised.

When explained systematically and logically, the customer is much more likely to respond positively to the recommendation for the service, and to feel that they have enough information to make a wise decision.

At the same time, using phrases such as “this engine builds carbon there because it is a bad design” should not be used. It is safe to say that the individuals that make statements like that would not know where to start in designing something as complex as an engine to meet the performance, efficiency, emissions, space and cost considerations that are required.

Every engine will be susceptible to some condition that will yield deposits and future problems. A true professional will know the basics of the engine design and what services will help the owner enjoy the longest engine life, lowest fuel costs and bet performance for that particular vehicle.

Conclusions
With good overall knowledge of the various locations where carbon deposits can cause performance issues, and the tools available to address these problems, customers are in a better position to accept the recommendations of a technician or service writer, and the technician is better positioned to provide a service that creates value for the customer.

In review, the key points to remember are:
· All engines will develop some degree of carbon
· The fuel system impacts the oil and the breakdown of engine oil will affect the fuel system through the PCV, on intake valves through the valve guides, and through loss of oil control because of ring issues
· Driving patterns, fuel quality, maintenance habits, ethanol levels in fuel, and engine design will determine the extent and location of the carbon
· Most carbon does not create a problem, and in absence of an effective post-combustion cleaner, should be left where it is so it does not contaminate the O2 and the cat. A fuel service that does not address O2 and cat contamination should not be sold as a “preventative maintenance service”.
· Most chemical cleaning services, especially induction services, should be done to address a specific performance issue, not for preventative maintenance, unless it is for an engine design with known susceptibility to intake deposits
· Most customers will notice no improvement and many times, a decrease in performance after a preventative maintenance fuel service because deposits are moved from the top of the engine onto the oxygen sensor.
· Quick lubes are for oil changes, not professional services. Fuel system cleanings should be done by a certified technician, who can diagnose the need for one, and be able to complete a fuel rail service
· If a chemical service is required to clean the intake area, it is important that a top quality formulation be used, and administered by a certified technician to maximize effectiveness and reduce the risk to the vehicle. The cost difference between a cheap chemical and a quality alternative is minimal, (probably never more than $10), but the difference in effectiveness will be noticeable
· Technicians should know the formulation of the chemicals they use, not the brand or product name. They can then know that they are using the best formulation for the problem, and they can stop overpaying for those non-proprietary formulations from “national” chemical distributors
· Uview Ultraviolet’s Terraclean system is the only system currently that offers the breadth of cleaning (throttle body to catalytic converter) to be confidently used as a preventative maintenance service
· A gasoline-based approach like Terraclean is preferred over chemical solvents and detergents. Chemicals should be used as a last resort, and targeted to specific problems
· Preventative maintenance intervals should be evaluated based on driving patterns, fuel quality used, maintenance habits, and engine design. The best rule of thumb is as an annual “tune up”
· Injector or induction services should not be sold as a stand alone service. A Terraclean post combustion cleaning should be used in combination with these services to clean any down stream fouling.
· Special care should be taken to use chemicals for cleaning the top of the engine that have been demonstrated to have minimal or no negative impacts on the oxygen sensor(s) and catalytic converter(s). Terraclean Injector Cleaner for injectors, and Well-Worth’s ProShock for induction cleaning, are two noteworthy offerings to accomplish this.

Please e-mail comments to vsp@insightbb.com

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