Abstract:
A device and method for cleaning the air-intake system of an EGR-valve-equipped diesel engine includes a dispersion component which mixes air and a liquid cleaning solution before delivering them to the air intake system of a running diesel engine. A main air intake is blocked and the EGR valve is removed and replaced with a coupler that receives the dispersion component, whereby a pressure drop is created. The pressure drop creates sufficient vacuum so that cleaner may be administered into the air-intake duct of the running engine. The cleaning solution is provided to the dispersion component under pressure supplied by a pressurized air source.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application, having attorney docket number BGPI.133819, is a continuation-in-part of pending application Ser. No. 10/722,302, attorney docket number BGPI.108186, filed Nov. 25, 2003, which claims the benefit of U.S. Provisional Application No. 60/478,582, filed Jun. 13, 2003. All of the aforementioned applications are incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates generally to the field of cleaning the engine systems of diesel vehicles. More specifically, the present invention relates to a method of cleaning the air intake systems of diesel vehicles. Even more specifically, the present invention relates to the use of a device to introduce carefully controlled amounts of cleaning solution into the air supply system such that the entire air supply system is cleaned. The device is configured to create a vacuum within the air intake system such that the cleaning solution passing therein remains, substantially airborne, and thereby distributed throughout the entire air supply system.  
         [0005]     2. Description of the Related Art  
         [0006]     Motor vehicle engines, whether they use gasoline or diesel fuel, have three fundamental components that participate in the combustion process - an air intake duct, a combustion chamber (or chambers), and an exhaust duct. It used to be that both gasoline and diesel engines would intake air (containing oxygen) in through the air intake system, and for gasoline engines, fuel would be mixed with the air prior to entering the combustion chamber. With respect to the traditional diesel engine, the air was typically injected directly into the combustion chamber. For both systems, however, only fresh, uncombusted air would be present in the entire system upstream from the combustion chamber. After combustion, undesirable, contaminating hydrocarbons (“soot”) would form as a by-product of combustion and cling to components in the combustion chamber and exhaust system. With respect to the combustion chamber, the intake and exhaust valves, piston head, and side walls would be undesirably lined with soot. With respect to the exhaust system, its components would also be covered.  
         [0007]     In order to remove this soot, cleaners could be mixed with the fuel before it was introduced into the combustion chamber. The introduction of cleaners into the combustion chamber effectively cleaned the combustion chamber and the down stream exhaust system. This method, however, did not clean the air intake system as it is upstream of the combustion chamber. Because the air intake systems were only exposed to clean, outside air, they did not require frequent cleaning.  
         [0008]     Later, exhaust gas recirculation (“EGR”) was introduced into gasoline engines. An EGR system takes a portion of the combusted-exhaust gas from the exhaust system, and loops this portion back into the air intake duct of the vehicle. Once reintroduced into the air intake duct, and mixed with fresh air, this portion of already combusted air serves to make the overall combustion process less environmentally harmful.  
         [0009]     Though great for the environment, this recirculation process had a major practical disadvantage in that it resulted in soot being recirculated along with the exhaust gas. This now introduced soot or dirty air into the air intake system for the first time. It also introduced soot into the new valve that made exhaust gas recirculation possible, i.e. the EGR valve. As a result, now that soot was present upstream from the combustion chamber, new methods had to be developed to clean soot from these places. The prior art methods of simply adding cleaner into the fuel would not work because the cleaning solution would not contact the upstream air intake system.  
         [0010]     To overcome this obstacle, technicians used several different methods. One such method involved spraying a cleaner into the air intake system to “decarb” at the point of air introduction. This procedure didn&#39;t work very well, because it didn&#39;t adequately clean the EGR valve (again, the point at which the recirculated air is introduced into the air intake system). To overcome this, technicians began spraying cleaners, either alternatively or additionally, into the EGR valve itself. The vacuum created by gasoline engines drew in enough air volume with adequate velocity to carry the cleaner through the EGR valve for cleaning purposes. These methods are still the most effective way to clean gasoline engines with EGR systems.  
         [0011]     Recently, however, EGR systems have also been added to diesel engines. This has created quite a dilemma for technicians wishing to adequately clean these new systems because the combustion chambers in diesel engines create a weaker vacuum than those in gasoline engines. As a result, the prior art methods of simply spraying cleaner in through the EGR valve will not work because there is not enough vacuum to draw the cleaner in through the system. Thus, there is a need in the art for a cleaning technique that permits the cleaning of an EGR system and air intake system on a diesel engine.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention includes a method, an apparatus and a cleaning solution that provide for the cleaning of air intake system and the EGR valve of a diesel engine having an EGR system, while avoiding many of the problems inherent in the prior art. In short, the apparatus causes a pressure drop within the diesel engine&#39;s air intake system. The pressure drop increases the velocity of the air flowing through the system. The increased air velocity artificially increases the vacuum and helps carry the cleaning solution, which is injected into the air stream, throughout the air intake system, thereby completely cleaning the system without the need to manually scrape off any deposits. The apparatus also creates additional turbulence within the air flowing through the intake system. This increases the distribution of the cleaning solution through all parts of the air intake system and ensures contact therewith. The apparatus also carefully controls the rate the cleaning solution is injected into the diesel engine&#39;s air intake system so that the engine is not harmed during the cleaning process. While prior art cleaning solutions can be used with the apparatus, a cleaning solution having a new chemical formulation which is particularly useful in cleaning diesel engines, and which has been specifically designed to be used with the apparatus disclosed herein, is also provided. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0013]     The present invention is described in detail below with reference to the attached drawing figures, wherein:  
         [0014]      FIG. 1  is a view of an EGR-equipped air intake system with an EGR valve removed in preparation for cleaning contaminants off the inside surface of an air-intake duct;  
         [0015]      FIG. 2  is an overview of the cleaning system with the parts of the diesel engine air intake system shown;  
         [0016]      FIG. 3  is an exploded view of a dispersion component and a liquid flow controller illustrating how the two components and related parts are assembled;  
         [0017]      FIG. 4 . is a side elevational view of the dispersion component and liquid flow controller assembled together;  
         [0018]      FIG. 5 . is a perspective view of the dispersion component;  
         [0019]      FIG. 6 . is a side elevation view of the dispersion component;  
         [0020]      FIG. 7  is a cross sectional view of the dispersion component taken along the line  7 - 7  of  FIG. 5 ;  
         [0021]      FIG. 8  is a bottom perspective view of an EGR valve port adapter;  
         [0022]      FIG. 9  is a left side elevational view of an EGR valve port adapter of  FIG. 8 ;  
         [0023]      FIG. 10  is a rear side elevational view of the EGR valve port adapter of  FIG. 8 ;  
         [0024]      FIG. 11  is a cross-sectional view of the EGR valve port adapter taken along the line  11 - 11  of  FIG. 10 ;  
         [0025]      FIG. 12  is a cross-sectional view of the EGR valve port adapter taken along the line  12 - 12  of  FIG. 10 ;  
         [0026]      FIG. 13  is a perspective view of the mouth adapter; and  
         [0027]      FIG. 14  is a cross-sectional view of the mouth adapter taken along the line  14 - 14  of  FIG. 13 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     The present invention includes an apparatus that allows a user to clean the air intake system  100  of a diesel engine (not shown) having an EGR system and avoid the problems inherent in the prior art. The apparatus causes a pressure drop within the diesel engine&#39;s air intake system  100 , thereby increasing the velocity of the air flowing through the system. The increased air velocity helps carry a cleaning solution, which is injected into the air stream, throughout the air intake system. As a result the entire air intake system is cleaned without the need to manually scrape off deposits.  
         [0029]     The decrease in pressure within the air intake system  100  is created by limiting the amount of air the engine is allowed to draw in while running. This is done by plugging one of the normally two air-intake system openings and placing a vacuum control device  300  on the other opening. While the engine is running, cleaning solution (not shown) is injected into the vacuum control device  300  where it is mixed with inlet air that is being drawn into the vacuum control device. Because of the increased air velocity created by the lower pressure within the air intake system  100 , the cleaning solution is distributed throughout the air intake system  100  resulting in improved cleaning. Without the increased air velocity, the cleaning solution would not be carried throughout the air-intake system.  
         [0030]      FIG. 1  shows a typical air intake system  100  for a diesel engine (not shown). Air is supplied to the air-intake system  100  through two openings. The first opening is the primary air intake  50 , which is normally coupled to an air hose (not shown) with an air filter (not shown) located at the end of the hose. The second opening is the EGR valve port  11 . Normally an EGR valve is coupled with the EGR valve port  11 ; however, for clarity, the EGR valve has been removed. Air from both openings combine in a duct  80  that leads to the combustion chamber of the engine. Normally, the EGR valve is attached to the EGR valve port  11  by bolts  40  which are received through apertures  15 .  
         [0031]     In order that the present invention be implemented, the air hose (not shown) is uncoupled from a mouth  52  of the primary air intake  50 . The EGR valve is also removed from the EGR valve port  11  by removing bolts  40 . Once removed, the EGR valve will be thoroughly cleaned manually (separately from the other processes described here) in a manner known to those skilled in the art. The EGR valve is then set aside, pending reattachment. The EGR valve port  11 , the mouth thereof now exposed in the absence of EGR valve, will usually be visibly dirty. This is especially true if the vehicle has been driven for significant mileage. The technician will notice substantial build-up of hydrocarbons on the cylindrical interior surface of the EGR valve port  11 . This buildup is often found throughout the air intake system  100  in varying concentrations.  
         [0032]     This build-up poses many problems. The prior art method of cleaning this soot, was to either brush or chisel it away with hand-held tools. This technique, however, is risky, because dislodged particles commonly become knocked into duct  80  and ultimately end up being drawn into the combustion section of the engine. Because they are very hard and relatively large with respect to what can be tolerated by the combustion systems of the engine, significant engine damage is a possibility. The present invention avoids this risk by removing the impurities using a cleaning solution that dissolves the solids so they can pass safely through the combustion chamber.  
         [0033]      FIG. 2  shows the equipment that will be assembled to deliver the cleaning solution into the air intake system  100 , thereby removing soot from the wall of the system. First, an EGR valve port adaptor  400  will be bolted onto the EGR valve port  11  in the same fashion as the EGR valve would normally be attached. The EGR valve port adapter  400  will be described in more detail below with reference to  FIGS. 8-12 . A vacuum control device  300  may then be coupled with the installed valve port adapter  400 . A receiving socket  410  of the EGR valve port adapter  400  is configured to receive either a plug  150  or the vacuum control device  300 , depending on the area to be cleaned.  
         [0034]     Next, a primary air intake adapter  540 , described in more detail with reference to  FIGS. 13 and 14 , may be attached to the mouth  52  of the primary air intake  50 . A receiving socket  542  in the primary air intake adapter  540  is configured to receive either the plug  150  or the vacuum control device  300 , depending, again, on the area to be cleaned. As explained in more detail hereafter, the plug  150  is placed in the primary air intake adapter  540  when the vacuum control device  300  is connected to the EGR valve port adapter  400 . After the air intake system  100  is cleaned through the EGR valve port  11 , the process is repeated with the plug  150  being placed in the EGR valve port adapter  400  and the vacuum control device  300  being installed in the primary air intake adapter  540 . This time, however, the cleaning solution is injected through the primary air intake  50 .  
         [0035]     The cleaning solution to be inserted into the system is maintained under pressure in a cleaning solution vessel  250 . Pressure is maintained in the cleaning solution vessel through supplied air (not shown) that enters the vessel through a regulator  260 . The regulator  260  maintains pressure in the cleaning solution vessel  250  between 5 and 120 psig. In a preferred embodiment the pressure is maintained between 60 and 80 psig. The cleaning solution enters the cleaning solution vessel  250  through a sealable opening  252 . A handle  254  with a hanger  256  is connected to the top of the cleaning solution vessel  250  for the convenience of the technician. The pressure provides the motive force for the solution to flow from the cleaning solution vessel  250  through a shutoff valve  262  to the vacuum control device  300  by way of a hose  264 . A preferred composition for this cleaner will be described hereinafter.  
         [0036]     The vacuum control device  300 , described in more detail with reference to  FIGS. 3-7 , consists of a dispersion device  322  and a liquid flow controller  324 . The liquid flow controller  324  controls the flow of cleaning solution into the dispersion device  322  where it is mixed with air, as hereinafter explained. The liquid flow controller  324  is controlled by a control panel  270 . The control panel  270  is electrically connected to the liquid flow controller  324  through control wires  272  attached to the control panel  270  on one end and a plug  274  on the other. The liquid flow controller  324  has a receptacle  376  adapted to mate with plug  274 . In one embodiment, power is supplied to the control panel  270  through leads  278  and  279  that are attached to the positive and negative poles on a battery (not shown) by way of clamps  280  and  281 . It is well understood by those of ordinary skill in the art that power could be supplied to the control panel  270  in a variety of different manners, all of which are contemplated to be within the scope of the invention.  
         [0037]     In one embodiment, the control panel  270  is pre-programmed to feed the cleaning solution through the liquid flow controller  324  at a high rate and a low rate. The control panel  270  also has an “off” setting where the liquid flow controller  324  remains in the closed position. In one embodiment, the low rate setting delivers approximately a quart an hour to the system, while the high rate delivers approximately a quart every  45  minutes. Feeding cleaning solution into the engine at a rapid rate can cause engine damage. The low rate is low enough that no engine problems should be caused regardless of the amount of fouling in the engine. The high rate should work with most engines, under most conditions. However, if the engine begins to knock or chatter while feeding solution at the high rate, the solution flow should be turned off. Once the engine begins to run without clattering or knocking, the solution may be delivered again, but at the lower setting.  
         [0038]     In one embodiment the rate of delivery is controlled via a knob  282  on the exterior of the control panel  270 . It is well understood by those having ordinary skill in the art that there are many ways to receive rate input from the user including but not limited to a switch, a dial, a keypad, or a touch screen. Any known means of receiving input from the user is contemplated to be within the scope of this invention. Further, even though two rate settings are discussed in the preferred embodiment, described above, any number of rate settings or a variable rate control device could also be used.  
         [0039]     It is also well understood that the rate of flow through liquid flow controller  324  can change depending on the pressure differential through the liquid flow controller  324 . For this reason the regulator  260  should be sent to maintain the pressure in the cleaning solution vessel  250  to the pressure upon which the control panel  270  rate settings were based.  
         [0040]     The details regarding adaptor  400  are disclosed in  FIGS. 8-12 . Adaptor  400  has an outwardly extending cylindrical portion  415  and a body  419  which is also cylindrical in the preferred embodiment. Cylindrical portion  415  defines a cylindrical opening  460  through cylindrical portion  415 . Cylindrical portion  415  has a diameter that is slightly smaller than the diameter of the opening  12  in the EGR valve port  11 . Cylindrical portion  415  has two slots  426  and  428  therein opposite each other adjacent the body  419 . The slots  426 ,  428  are of sufficient depth to cut into a passage  450  through the adapter  300 . Cylindrical portion  415  also has a pair of annular grooves  430  in an outer surface  432  thereof. The grooves  430  receive  0 -rings  434  to seal the connection when the adapter  400  is received in the air intake system  100 . Body  419  has a pair of flanges  418 . The flanges  418  have holes  417  therethrough for receiving the bolts  40  to attach the adaptor  400  to the EGR valve port  11 .  
         [0041]     The body  419  defines a receiving socket  462  which is slightly larger than the insertion section  325  of the vacuum control device  300  and the insertion section  152  of the plug  150 . The body  419  also defines a cone shaped reducing section  464  which connects the receiving socket  462  with the cylindrical opening  460  and which together define the passage  450  through the adapter  400 . A threaded hole  420  is disposed radially through body  419  in order to receive a thumbscrew  421 . The thumbscrew  421  is used to secure the vacuum control device  300  or the plug  150  in the receiving socket  462 . A handle  466  is attached to the body  419  to facilitate removal of the adapter  400  from the EGR valve port  11  or the primary air intake adapter  540 .  
         [0042]     Vacuum-control device  300  is attached once adaptor  400  has been bolted onto flange  15  of EGR valve port  11 . The details of the vacuum control device  300  are shown in  FIGS. 3-7 . The outside diameter of the insertion end  325  of the vacuum control device  300  is infinitesimally smaller than the inside diameter of the receiving socket  462  of the adaptor  400 . These dimensions allow the insertion end  325  to be slidably received inside the receiving socket  462  defined by the body  419  of the adaptor  400  until the insertion end  325  reaches a ridge  470  within the receiving socket  462 . Once the insertion end  325  has been abutted against the ridge  470 , the device  300  is secured within the adaptor  400  by screwing in the thumbscrew  421 . The tip of the thumbscrew  421  engages an outer surface  327  of the insertion end  325  of the vacuum control device  300 . The vacuum control device  300  is now securely held within the adapter  400 . The insertion end  152  of the plug  150  would be secured in the adapter  400  or the adapter  540  in substantially the same manner.  
         [0043]     The functional features of device  300 , illustrated in  FIGS. 3-7 , will now be described. Evident in  FIG. 3  is that the device  300  is divided into two separate components. One is a dispersion device  322  and the other is a liquid flow controller  324 . The liquid flow controller  324  is fixed to the dispersion device  322  by two bolts  310  and  312 . The bolts  310 ,  312  are fed through holes  320  and  318  of a flange  328  at the base of the liquid flow controller  324  and into threaded holes  314  and  316  in the top section  326  of the dispersion device  322 . A tube  320  protrudes from the liquid flow controller  324  through a hole  332  in the top of the dispersion device  322 .  
         [0044]     The liquid flow controller  324  has the ability to rapidly start and stop the flow of cleaning solution. In one embodiment, the liquid flow controller is a standard fuel injector. The liquid flow controller  324  receives an open/close signal from the control panel  270 . In one embodiment, the cleaning solution is fed intermittently into the dispersion device  322  at a rate of on for three seconds and then off for three seconds. The liquid flow controller  324  has the electrical receptacle  376  that connects with the plug  274  of the wire  272  that carries the signal from the control panel  270 .  
         [0045]     The cleaning solution enters the liquid flow controller  324  through nozzle  368 . Cleaning solution is fed into nozzle  368  by a banjo fitting  360  and banjo bolt  370 . A washer  364  is used between the banjo fitting  360  and banjo bolt  370 . A second washer  366  can be used between the liquid flow controller nozzle  368  and the banjo fitting  360 . In one embodiment, both washers are copper. The cleaning solution enters the banjo fitting  360  through hose  264  which is connected to the inlet  362  of the banjo fitting  360 . Those of ordinary skill in the art will be familiar with the proper use of banjo nuts and fittings.  
         [0046]     The dispersion device  322  defines mixing chamber  382  that is open at the insertion end  325 . Bored through the cylindrical side wall of the dispersion device  322  are several air inlet apertures  330 . The air inlet apertures are preferably bored non-radially and sloped towards the opening of the dispersion device. In one embodiment, the apertures are sloped downward  39  degrees and  45  degrees from radial, but variations on this orientation are also suitable. The orientation of the apertures  330  creates a swirl of air within the mixing chamber  382 . The swirl of air helps carry the droplets of cleaning solution into the air stream. The apertures  330  are sized to allow the engine to draw in just enough air to allow the engine to run without difficulty. In one embodiment, the dispersion device  322  has 12 apertures  330 , each with a diameter of 0.15 inches.  
         [0047]     The primary air intake adapter  540  is described with reference to  FIGS. 13 and 14 . The primary air intake adapter  540  includes a receiving section  560  and a primary air intake coupling section  570 . The receiving section  560  is cylindrical in shape and defines a cylindrical receiving socket  542 . The receiving socket  542  is configured to receive the insertion end  152  of the plug  150  or the insertion end  325  of the vacuum control device  300 . A threaded hole  519  is disposed radially through the receiving section  560  in order to receive a thumbscrew  521 . Once the insertion end  325  has been abutted against ridge  566 , the device  300  is secured within the primary air intake adaptor  540  by screwing in the thumbscrew  521 . The tip of the thumbscrew  521  engages the outer surface  327  of the insertion end  325  of the device  300 . The device  300  is now securely held within the adapter  400 . The insertion end  152  of the plug  150  is secured in the primary air intake adaptor  540  in substantially the same manner.  
         [0048]     The primary air intake coupling section  570  defines a receiving socket that is the same shape, but slightly larger than the mouth  52  of the primary air intake  50 . In most cases, the mouth  52  of the primary air intake  50  will be cylindrical. The primary air intake coupling section  570  is configured to slide over the mouth  52  of the primary air intake  50 . Once the mouth  52  of the primary air intake  50  is slid inside the primary air intake coupling section  570 , it is secured with three thumb screws  572 ,  574 , and  576 . Threaded holes  578 ,  580 , and  582  are disposed radially through the primary air intake coupling section  570  in order to receive thumbscrews  572 ,  574 , and  576 .  
         [0049]     Receiving section  560  and primary air intake coupling section  570  define an opening  590 . The opening  590  allows cleaning solution to pass from the vacuum control device  300 , into the receiving section  560 , through the primary air intake coupling section  570  and then into the primary air intake  50 .  
         [0050]     Once a desired amount (e.g. a quart) of cleaning solution has been fed into the air intake system  100  through the EGR valve port  11 , the portion of the plug  150  and the vacuum controller  300  are swapped. A second amount of cleaning solution is then fed through the vacuum controller  300 , which, in the sequence illustrated herein, would be attached to the primary air intake adapter  540 , which in turn is attached to the primary air intake  50 . If the diesel engine contains more than one air intake system, then the process will need to repeated with the second EGR valve port (not shown) and the second primary air intake (not shown). Additionally, the cleaning process may be repeated from either opening if additional cleaning is required.  
         [0051]     Once cleaning has been completed, the vacuum control device  300 , the EGR valve port adapter  400 , and the primary air intake adapter  540  are removed from the air intake system  100 . This is done by removing the bolts  40  from the flange  15  surrounding the mouth of the EGR valve port  11 . The EGR valve is then bolted back onto EGR valve port  11  using the bolts  40 .  
         [0052]     Because the EGR valve has been thoroughly cleaned manually (usually by soaking, scrubbing, scraping, etc.), and the EGR valve port  11  has been cleaned by the vacuum-controlled process described above, the entire system is completely cleaned and is ready to be returned to service with its operating condition being improved.  
         [0053]     It has been determined that a particular cleaning solution is especially effective for use in the process described above. In one embodiment, the cleaning solution comprises five separate components. However, it should be noted that the device described above can effectively clean an engine with numerous solutions.  
         [0054]     A first component in the cleaning solution is a solvent which should be highly polar. It is a well-understood principle that highly polar solvents are ideal for cleaning contaminants of high polarity. The typical soot, which accumulates on the air intake system and combustion chambers in a diesel vehicle, tends to have extremely high polarity. Thus, a highly polar solvent effectively removes these contaminates. The solvent used in one embodiment, is propylene carbonate (4-methyl-1,3-dioxolan-2-one) at 30 to 60 mass percent, and in another embodiment at 43% mass percent. Alternatively, closely-related highly-polar solvents ethylene carbonate and butylene carbonate may be used in this process. Mixtures of propylene carbonate, ethylene carbonate and butylenes carbonate could also be used and still fall within the scope of the invention.  
         [0055]     Propylene carbonate has proved to be outstanding, not only because it is ideal for cleaning highly-polar contaminants, but also because of its combustibility properties. Propylene carbonate combusts well when run through a diesel system, unlike many other highly polar solvents. Not only does the propylene carbonate remove the deposits, but when used with the special equipment described in the application earlier, its chemistry does not significantly affect the combustion process. Another advantage is that propylene carbonate is relatively non-toxic and environmentally friendly.  
         [0056]     Though propylene carbonate is used in this specific embodiment, other highly polar solvents, however, could be used as the first component of the cleaner as well. The use of any other highly polar solvent could be used so long as it is reasonably accepted by the diesel combustion in the vehicle engine. Thus, other highly-polar solvents could be used as the first component and still fall within the scope of the present invention.  
         [0057]     In one embodiment, a second component is also included in the cleaning solution. The second component of the cleaner is a low polarity solvent at 30 to 60 mass percent, and in another embodiment at 43% mass percent. Preferably, the low polarity solvent would be included at a roughly equal proportion to the high polarity solvent described above.  
         [0058]     The low-polarity solvent is added to the cleaner to more adequately dissolve low-end hydrocarbons present in the air intake system and combustion chamber. Aside from the extremely hard highly-polar contaminants clinging to the metal surfaces within the air intake and combustion systems, low-end hydrocarbons, such as oils and diesel fuels, are also re-circulated along with the exhaust in an EGR system. It is well known in the art that these low-end hydrocarbons are more easily removed with a low-polarity solvent. One example of a solvent that could be used effectively for such purposes is an aeromatic solvent. Some examples of aeromatic solvents that may be used effectively would be toluene, zylenes, cumenes, or any other low-polarity solvent that would not significantly impede the diesel combustion process. An aromatic solvent can be used that has a boiling range between 200 to 700 degrees Fahrenheit.  
         [0059]     Surfactants may also be added as a third component to the formulation at 1 to 10 mass percent. In another embodiment, the surfactants are included at 3 mass percent. Surfactants enhance the cleaning of the harder baked-on deposits found on intake valves in the lower section of the air plenum as it meets the engine head. Surfactants also help the other chemistry penetrate and dissolve the deposits. Both non-ionic and ionic surfactants are suitable for inclusion in the formulation. However, non-ionic surfactants have been found beneficial. Ethoxylated linear secondary alcohols or mixtures of the same are effective non-ionic surfactants that could be included in the formulation.  
         [0060]     The formulation may be further improved by the addition of a fourth component. The fourth component, in one embodiment, is a compound with functional ketone chemistry at 1-10 mass percent. In another embodiment, the functional ketone is included at 1-2 mass percent. In yet another embodiment, Cyclohexanone is used to provide the functional ketone chemistry. Cyclohexanone is an effective solvent that is water soluble. The water solubility of the Cyclohexanone and other solvents with functional ketone chemistry helps dissolve deposits that the other solvents might not effectively dissolve.  
         [0061]     A fifth suggested component in the formulation is a fatty amide at 1 to 20 mass percent. In one embodiment, fatty amides are included at 10 mass percent. Fatty amides act as a dispersant and effectively remove fuel related deposits. In another embodiment, Hallcomid® M-10, N,N Dimethyldecanamide CAS# 14433-76-2 is used as the fatty amides. Other fatty amides work well, so long as they have good heat stability so they do not quickly decompose in the heat from the engine. Suitable fatty amides should also have good solubility with other solvents to be an effective component of the formulation.  
         [0062]     The percentage by volume of propylene carbonate used within the formulation, preferably ranges from 30 to 60 percent of the overall volume. In one embodiment, propylene carbonate would comprise about 42 percent of the overall formulation. In this embodiment, the second low-polarity solvent would comprise approximately 43 percent of the formulation. The surfactant, fatty amide, and functional ketone chemistry will make up the balance.  
         [0063]     For example, one embodiment of the formulation could be: 
        between 40 and 45 mass percent of propylene carbonate;     between 40 and 45 mass percent of toluene;     between 1 and 5 mass percent of a non-ionic surfactant;     between 5 and 15 mass percent Hallcomid® M-10, N,N Dimethyldecanamide CAS# 14433-76-2; and     between 1 and 5 mass percent of Cyclohexanone.        
 
         [0069]     It is important to note that, though first, second, third, fourth and fifth components have been included in the formulation illustrated here, any cleaning solution could be administered according to the claimed process and would still fall within the scope of this invention. Further, the first and second components could both be administered at separate times and still fall within the scope of this invention. The use of the third through fifth components is entirely optional, but does improve the cleaning process.  
         [0070]     The solution is made by mixing the components together in a vessel with moderate agitation. When mixing the components, the aromatic solvent should be added prior to adding the propylene carbonate to assist the propylene carbonate with entering the solution. The order of adding the other components of the formulation does not effect the solution. In one embodiment, the formulation is made in a batch process with the entire amount of each component being added in full rather than in increments. Once all of the components are added the solution is agitated for about an hour. The components used in the specific embodiment disclosed herein readily form a solution. One having ordinary skill in the art will understand that the mixing time can be lengthened or shortened depending on the amount of agitation supplied. Moreover, multiple forms of agitation could be used including, but not limited to, recirculation pump systems or motorized mixing blades with or without a baffle. Once completed, the solution may be stored in tanks or totes. For final use, the solution may be further packaged into consumable sized portions. In one embodiment, the solution is packaged into quart sized consumable containers, and in another embodiment into F-style quart bottles.  
         [0071]     In a further embodiment, a diesel engine may be cleaned entirely with chemicals when the air intake system is cleaned with the apparatus and solution described hereinabove, and an internal engine cleaner is added to the engine oil system whereby deposits are removed from a fuel injector hydraulic system. In this manner, the two areas of a diesel engine most susceptible to fouling are cleaned without labor intensive scrapping and with only minimal disassembly. Adding an internal engine cleaner to the engine oil is well known to those of ordinary skill in the art and for that reason is not described in detail herein.  
         [0072]     Although the invention has been described with reference to the preferred features of various embodiments illustrated in the attached, and described in the above description, one skilled in the art will recognize that numerous substitutions could be made and the equivalents employed herein without departing from the scope of the invention, which is more properly defined as it is recited in the claims which, of course, are subject to amendment.