METHOD FOR INJECTING A CLEANING PRODUCT INTO THE COMBUSTION CHAMBER OF AN INTERNAL COMBUSTION ENGINE

Abstract

The invention relates to a method for injecting a cleaning product into an engine combustion chamber, each cleaning phase of which (A; B) successively comprises engine preheating (A1; B1), disconnection of the battery and removal of the ignition circuit (A2, A3, A4; B2, B3, B4), then a first injection of the product (A7; B7) for a duration of 5 seconds per cylinder, a first cranking of the starter (A9; B9) for a duration of 5 seconds, a second injection of the product (A12; B12) for a duration of 5 seconds per cylinder, a rest period (A13; B13) of 30 minutes, a second cranking of the starter (A15; B15) for a duration of 10 seconds, reinstallation (A18, A19; B18, B19) of the spark plugs and ignition coils, and a phase of engine running at a steady speed (A21; B21) for a duration of 30 minutes, followed by several engine accelerations (A22; B22), before a final phase (C) of draining and checking. Figure 1

Description

Title of the invention: METHOD FOR INJECTING CLEANING PRODUCT INTO A CHAMBER ENGINE COMBUSTION

[0001] The invention relates to a method of injecting a cleaning product into a combustion chamber of an internal combustion engine cylinder, delivered from a container containing a cleaning product.

[0002] The invention relates to the field of maintenance of internal combustion engines, and to that of oil consumption treatment tools.

[0003] To improve the performance of an internal combustion engine, it is advantageous to clean the combustion chambers, pistons, and in particular their piston rings. This type of operation is carried out as an aftermarket service, without specific equipment, by spraying the product using an aerosol can, and is particularly inconvenient. There is a health risk due to the toxicity of the product, and the resulting splashes and fumes, requiring operators to wear full protective equipment.

[0004] US patent 10590874B2 describes a system and method for cleaning a vehicle engine by spraying diesel exhaust fluid into the intake manifold to reduce carbon buildup in the engine cylinders. This particular method requires a supply circuit for such diesel exhaust fluid to the manifold, special precautions, and a specially equipped workstation.

[0005] No teaching is known which describes a procedure for cleaning a combustion chamber ensuring the reproducibility of the method of injecting product under pressure into the segmentation.

[0006] The invention seeks to solve several problems: - the reproducibility of the pressure injection method of the product in the segmentation, - health problems concerning operators (fumes, projections, possible contact with the product), - the significant number of times contaminated product is handled, - the frequent need for at least two operators to be involved during product injection, - the cost of protective equipment and its disposal, - the cost of disposing of consumables.

[0007] The objective of the present invention is to remedy these drawbacks by proposing a method to optimize the cleaning efficiency of combustion chambers, pistons and piston rings of internal combustion engines.

[0008] This process aims to optimize and enable the reproducibility of the product injection method.

[0009] To achieve this objective, the invention proposes a method of injecting cleaning product into a combustion chamber of an internal combustion engine cylinder, delivered from a container containing a cleaning product.

[0010] According to the invention, said method comprises at least one engine cleaning phase according to a predetermined sequence with predetermined durations for certain operations, followed by a final phase of draining, fitting new components and checking, said at least one cleaning phase comprising successively preheating the engine, then engine preparation operations by disconnecting the battery and removing the electrical ignition circuit, an operation to prepare said container, followed by a first operation of injecting said product into all cylinders for a short duration of less than 7 seconds per cylinder, reconnecting the battery and a first rotation of the starter for a short duration of less than 7 seconds, disconnecting the battery followed by a second operation of injecting said product into all cylinders for a short duration of less than 7 seconds per cylinder,of a rest period exceeding 10 minutes, reconnecting the battery and a second cranking of the starter for a duration of between 8 and 15 seconds, disconnecting the battery followed by reinstalling the spark plug and then the ignition coil, reconnecting the battery and running the engine continuously for a duration exceeding 10 minutes, and several engine accelerations lasting 3 to 5 seconds each, up to a speed exceeding 4000 rpm.

[0011] Thanks to the invention, cleaning an engine, necessary when the engine consumes too much oil, is a perfectly controlled and highly reproducible operation.

[0012] Advantageously, said cleaning phase is divided into two elementary cleaning phases, comprising the same operations, with the same timing, but in the reverse order of the engine cylinders.

[0013] Efficiency is greatly improved, at the cost of a longer but well-controlled operating time.

[0014] Advantageously, said first rotation at the starter has a duration of 4 seconds to 6 seconds, and said second rotation at the starter has a duration of 8 seconds to 12 seconds.

[0015] The strict control of the durations, which must be identical for all cylinders, guarantees the quantity of product injected into the engine and the reproducibility of the cleaning operation. It also prevents any waste of product.

[0016] Advantageously, said rest time has a duration of between 25 minutes and 35 minutes, and said continuous walking has a duration of between 25 minutes and 35 minutes at a speed greater than 2000 revolutions per minute.

[0017] The total duration of the cycle is thus well controlled.

[0018] Advantageously, said final phase of draining, fitting new components and checking, includes a first operation of preheating the engine until the fan starts, a second operation of stopping the engine, a third operation of removing the dipstick and the filler cap, a fourth operation of removing the drain plug within 4 minutes of stopping the engine, a fifth operation of draining for at least 20 minutes, a sixth operation of changing the oil filter, a seventh operation of refitting the drain plug, an eighth operation of filling with the recommended quantity of new oil, a ninth operation of checking the dipstick, a tenth operation of changing each spark plug, and an eleventh operation of clearing faults in the computer and a test drive.

[0019] The engine is thus completely and perfectly cleaned and reconditioned for its return to service.

[0020] Advantageously, after the aforementioned engine preparation operations by disconnecting the battery and removing the electrical ignition circuit, an operation is carried out to mount, on each cylinder of the engine, a specific tool intended for the direct injection into the cylinder of said cleaning product from said container without contact with the operator, said rigid specific tool being mounted in a sealing support under a high predetermined pressure greater than 15 bar on a sealing seat of the engine and rigidly fixed to the engine to ensure the maintenance of this sealing during the cleaning maneuvers, and, after the first and second phases of rotation with the starter and the disconnection of the battery, an operation is carried out to remove said specific tool allowing the reassembly of the spark plug and the ignition coil.

[0021] Thus, an after-sales technician can single-handedly remove the ignition coil and spark plug from the same cylinder, easily replace them with a rigid tool that is easy to handle alone, position this tool to create a seal on the spark plug seat, and rigidly fix this tool to the engine, thereby ensuring a seal and resistance to pressure. The specific tool protects the operator from any contact with the cleaning product, whether new or contaminated. An injection nozzle allows the cleaning product to be projected to the optimal location. The fact that the thread is not used The candle allows the use of a tool with an awkward shape, compatible with the available access points.

[0022] Advantageously, said specific tool includes an expansion vessel arranged to deal with possible backflow of said cleaning product.

[0023] Thus it is possible to deal with any backflow of cleaning product, without danger to the operator.

[0024] Advantageously, said specific tool includes a connecting element arranged for its quick-release snap-on mounting with said container.

[0025] This arrangement ensures safety and the absence of contact between the operator and the product.

[0026] Advantageously, after said first injection of product into the cylinder, a first operation of plugging the spark plug housing with a cloth takes place, and an operator ensures that said cloth is held in place during the first phase of rotation at the starter, after which said cloth is removed, after said second injection of product into the cylinder, a second plugging of the spark plug housing with a cloth takes place, and an operator ensures that said cloth is held in place during the second phase of rotation at the starter after which said cloth is removed.

[0027] Thus, an after-sales workshop not having the specific tool used elsewhere, can implement the process according to the invention.

[0028] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig.1] illustrates, in the form of a block diagram, a first variant of the process according to the invention, implementing a specific tool, and which can be carried out by a single user; - [Fig.2] illustrates in the form of a block diagram, a second variant of the process according to the invention, not requiring a specific tool, but the presence of two operators; - [Fig.3] schematically illustrates a variant of a specific tool, assembled to a container of cleaning product; - [Fig.4] schematically illustrates a variant of a specific tool, equipped with an expansion vessel to deal with product backflow.

[0029] The invention describes a method for optimizing the cleaning efficiency of combustion chambers, pistons and piston rings of internal combustion engines.

[0030] The method according to the invention comprises at least one engine cleaning phase according to a predetermined sequence with predetermined durations for certain operations, followed by a final phase of draining, fitting certain new components such as oil filter and spark plugs, and checking.

[0031] Advantageously, the cleaning phase is split into two elementary cleaning phases, comprising the same operations, with the same timing, but in the reverse order of the engine cylinders.

[0032] A first variant of this process implements a specific tool 100 requiring a single operator, and limiting the number of operations.

[0033] More specifically, this method employs a specific tool 100, unique to the type of engine concerned, as it is mechanically fixed to a cylinder by means of a rigid and pressure-tight mounting. This tool allows the injection of cleaning product into a combustion chamber and ensures a seal during rotation while the starter is engaged. This tool should reduce the number of personnel required during engine cleaning, prevent direct contact with the injected product, and limit the number of manipulations required during the engine piston ring cleaning procedure.

[0034] Adding such a tool to each cylinder ensures a seal during injection and prevents any direct contact between personnel and the injected product during the cleaning operation on the piston rings.

[0035] This first variant comprises three main phases A, B, and C.

[0036] The first elementary phase A of the first variant comprises a succession of operations, denoted Ax.

[0037] The first operation Al consists of heating the engine until the fan starts.

[0038] The second operation A2 consists of disconnecting the battery.

[0039] The third operation A3 consists of removing the ignition coil.

[0040] The fourth operation A4 consists of removing the spark plug.

[0041] The fifth operation A5 consists of installing a tool on each cylinder Specific tool 100. This specific tool 100 is rigid and designed to be mechanically fixed to the engine by a rigid connection, and to provide a seal against a seat in the spark plug housing. This specific tool 100 has, at one end, a connecting element 2 arranged to cooperate in a complementary and sealable manner with a container 200 containing a cleaning product, and at the other end, an injection nozzle 8 having at least one outlet 6 opening into the engine. In an advantageous embodiment, the specific tool 100 includes an expansion tank 13 to cope with any potential backflow of the cleaning product. The user never touches the cleaning product, but only the specific tool 100 and the container 200 of aerosol cleaning product.

[0042] The sixth operation A6 consists of vigorously shaking a 200 container of aerosol cleaning product.

[0043] The seventh operation A7 consists of a first injection of the product into all cylinders, for a period of 2 to 7 seconds, in particular close to 5 seconds, per cylinder, from cylinder 1 to cylinder N (N being the number of cylinders in the engine).

[0044] The eighth operation A8 consists of connecting the battery.

[0045] The ninth operation A9 consists of commanding a first rotation for a period of 2 to 7 seconds, in particular 4 to 6 seconds, in particular close to 5 seconds, under the action of the starter.

[0046] The tenth operation A10 consists of disconnecting the battery.

[0047] The eleventh operation, Garlic, consists of vigorously shaking a 200 container of product aerosol cleaning.

[0048] The twelfth operation A12 consists of a second injection of the product into all cylinders, for a period of 2 to 7 seconds, in particular close to 5 seconds, per cylinder, from cylinder 1 to cylinder N.

[0049] The thirteenth operation A13 consists of taking a break with a rest period of 10 to 40 minutes, in particular 25 to 35 minutes, in particular close to 30 minutes.

[0050] The fourteenth operation A14 consists of connecting the battery.

[0051] The fifteenth operation A15 consists of commanding a second rotation for a period of 8 to 15 seconds, in particular from 8 to 12 seconds, in particular close to 10 seconds, under the action of the starter.

[0052] The sixteenth operation A16 consists of disconnecting the battery.

[0053] The seventeenth operation A17 consists of depositing the specific tools 100.

[0054] The eighteenth operation Al8 consists of reinstalling the spark plug.

[0055] The nineteenth operation A19 consists of reassembling the ignition coil.

[0056] The twentieth operation A20 consists of connecting the battery.

[0057] The twenty-first operation A21 consists of running the engine continuously for a period of 10 to 40 minutes, in particular 25 to 35 minutes, in particular close to 30 minutes, at a speed greater than 2000 revolutions per minute, in particular in the vicinity of 2500 revolutions per minute.

[0058] The twenty-second operation A22 consists of commanding several slow accelerations, in particular from 3 to 8, more particularly 5 accelerations, in particular of a duration of 3 seconds to 5 seconds up to a speed greater than 4000 revolutions per minute, in particular close to 4500 revolutions per minute.

[0059] The second elementary phase B of the first variant comprises a succession of operations, denoted Bx.

[0060] These Bx operations of the second phase B are identical to the Ax operations of the first phase A, except that the injection takes place from cylinder N to cylinder 1.

[0061] The third final phase C of the first variant comprises a succession of operations, denoted Cx.

[0062] The first operation Cl consists of heating the engine until the fan starts.

[0063] The second operation C2 consists of stopping the engine, preferably and not limited to 4 minutes after the fan has been started.

[0064] The third operation C3 consists of removing the gauge and the filler cap.

[0065] The fourth operation C4 consists of removing the drain plug within 4 minutes of stopping the engine.

[0066] The fifth operation C5 consists of draining for at least 20 minutes.

[0067] The sixth operation C6 consists of changing the oil filter.

[0068] The seventh operation C7 consists of reassembling the drain plug.

[0069] The eighth operation C8 consists of filling with the quantity of new oil Recommended.

[0070] The ninth operation C9 consists of checking the gauge.

[0071] The tenth CIO operation consists of changing each spark plug.

[0072] The eleventh operation Cl 1 consists of clearing the faults in the computer and perform the road test.

[0073] A second variant of this process, without specific tools, requires at least two operators, one of whom is responsible for ensuring that orifices are plugged with rags.

[0074] This second variant comprises three main phases D, E, and F.

[0075] The first elementary phase D of the second variant comprises a succession of operations, denoted Dx.

[0076] The first DI operation consists of heating the engine until the fan starts.

[0077] The second operation D2 consists of disconnecting the battery.

[0078] The third operation D3 consists of removing the ignition coil.

[0079] The fourth operation D4 consists of removing the spark plug.

[0080] The fifth operation D5 consists of vigorously shaking a container 200 of product aerosol cleaning.

[0081] The sixth operation D6 consists of a first injection of the product into all cylinders, for a period of 2 to 7 seconds, in particular close to 5 seconds, per cylinder, from cylinder 1 to cylinder N.

[0082] The seventh operation D7 consists of a first sealing of the spark plug housing with a cloth or similar material.

[0083] The eighth operation D8 consists of connecting the battery.

[0084] The ninth operation D9 consists of ensuring pressure on the cloth in the candle housing.

[0085] The tenth operation D10 consists of commanding a first rotation for a period of 2 to 7 seconds, in particular 4 to 6 seconds, in particular close to 5 seconds, under the action of the starter.

[0086] The eleventh operation DI 1 consists of disconnecting the battery.

[0087] The twelfth operation D12 consists of removing the cloth.

[0088] The thirteenth operation D13 consists of vigorously shaking a container 200 of aerosol cleaning product.

[0089] The fourteenth operation D14 consists of a second injection of the product into all cylinders, for a period of 2 to 7 seconds, in particular close to 5 seconds, per cylinder, from cylinder 1 to cylinder N.

[0090] The fifteenth operation D15 consists of a second sealing of the spark plug housing with a cloth or similar.

[0091] The sixteenth operation D16 consists of taking a break with a rest period of 10 to 40 minutes, in particular close to 30 minutes.

[0092] The seventeenth operation D17 consists of connecting the battery.

[0093] The eighteenth operation D18 consists of applying pressure to the cloth in the candle housing.

[0094] The nineteenth operation D19 consists of commanding a second rotation for a period of 8 to 15 seconds, in particular 8 to 12 seconds, in particular close to 10 seconds, under the action of the starter.

[0095] The twentieth operation D20 consists of disconnecting the battery.

[0096] The twenty-first operation D21 consists of reinstalling the spark plug.

[0097] The twenty-second operation D22 consists of reassembling the ignition coil.

[0098] The twenty-third operation D23 consists of connecting the battery.

[0099] The twenty-fourth operation D24 consists of running the engine continuously for a period of 10 to 40 minutes, in particular 25 to 35 minutes, in particular close to 30 minutes, at 2500 revolutions per minute.

[0100] The twenty-fifth operation D25 consists of commanding several slow accelerations, in particular from 3 to 8, more particularly 5 accelerations, in particular of a duration of 3 seconds to 5 seconds each, up to a speed greater than 4000 revolutions per minute, in particular close to 4500 revolutions per minute.

[0101] The second elementary phase E of the second variant comprises a succession of operations, denoted Ex.

[0102] These Ex operations of the second phase B are identical to the Dx operations of the first phase D, except that the injection takes place from cylinder N to cylinder 1.

[0103] The third final phase F of the second variant comprises a succession of operations, denoted Fx.

[0104] The first operation Fl consists of heating the engine until the fan starts.

[0105] The second operation F2 consists of stopping the engine, preferably and not limited to within 4 minutes of the fan starting.

[0106] The third operation F3 consists of removing the gauge and the filler cap.

[0107] The fourth operation F4 consists of removing the drain plug within 4 minutes of stopping the engine.

[0108] The fifth operation F5 consists of draining for at least 20 minutes.

[0109] The sixth operation F6 consists of changing the oil filter.

[0110] The seventh operation F7 consists of reinstalling the drain plug.

[0111] The eighth operation F8 consists of filling with the quantity of new oil Recommended.

[0112] The ninth operation F9 consists of checking the gauge.

[0113] The tenth operation F10 consists of changing each spark plug.

[0114] The eleventh operation, Fil, consists of clearing faults in the computer and perform the road test.

[0115] This method thus makes it possible to carry out an injection of cleaning product into a combustion chamber of a cylinder of an internal combustion engine comprising on the one hand a spark plug housing with a spark plug seat and a spark plug thread, and on the other hand an engine ignition coil housing and a coil fixing comprising a threaded housing or a stud, in particular for an internal combustion engine of a motor vehicle.

[0116] Such a cleaning product is designed to dissolve and remove the accumulation of harmful deposits on the pistons, piston rings, cylinder bore, and combustion chamber. This accumulation of harmful deposits is detrimental to vehicle performance, increasing fuel consumption, causing engine misfires, and increasing CO and NO emissions, and of course, accelerating engine wear. It is often an aerosol cleaner, a fuel additive, a valve cleaner, a carburetor cleaner, or a direct injection cleaner.

[0117] The first variant of the process according to the invention, implementing the specific tool 100, can be implemented by a single operator, who can thus advantageously avoid the constraints of wearing personal protective equipment (glasses, gloves, face mask, and suitable suit).

[0118] The specific tool 100, which can be operated by a single user, is preferably arranged to be positioned in place of an engine ignition coil, in using an identical fixing, in an ignition coil housing and in a spark plug housing of the same cylinder.

[0119] This tool 100 has a sealing surface, which is arranged to be mounted in support on a sealing seat of the engine, in particular a spark plug seat, and to withstand a high predetermined pressure, greater than 15 bar, in particular and not limited to about 20 bar, under a clamping force exerted, when the tool 100 is positioned in support on this spark plug seat, by means of at least one support element, which comprises the specific tool 100, comprising at least one fixing element on the engine cooperating with the engine coil fixing, under a clamping force exerted by this support element.

[0120] This sealing surface may in particular include a compression gauge type sealing gasket.

[0121] The variant of the specific tool 100 comprising a safety expansion vessel 13 allows, when the piston is at top dead center with all valves closed, and when the volume of injected cleaning product is greater than the volume of the combustion chamber, on the one hand to avoid hydraulic compression during the engine rotation phases, and on the other hand to keep an identical quantity injected into the cylinders.

[0122] Of course, one tool is required per cylinder (and preferably each one equipped with an expansion tank). The low unit cost of the tools allows for equipping any after-sales service at minimal expense.

[0123] The use of such a simple and inexpensive specific tool makes it possible to limit health risks (emission and projection of the product), the number of people involved, the operation can now be carried out safely by a single operator in a very ergonomic way, and the number of manipulations is greatly reduced.

[0124] In the second embodiment of the method according to the invention, the operation requires the presence of two operators: after the cleaning product is introduced, the inlet openings must be plugged with rags and then held in place. When the motor is started to circulate the cleaning product, these rags tend to come out through the dust cover opening, and therefore an operator is needed to hold them in place or replace them.The cycle requires attention to respecting the sequence and the management of supplies: after a first engine rotation of about 5 seconds, the product must be reinjected, the soiled rags discarded, the rags changed, then left to act for a period of 10 to 40 minutes, especially close to 30 minutes, before making a new engine rotation using the starter for a period of 8 to 15 seconds, especially close to 10 seconds, discard the soiled rags, replace the spark plugs, wait a period of 10 to 40 minutes, especially close to 30 minutes, and repeat the entire complete cycle. a second time. If this cycle is perfectly reliable, it requires two technicians, and bears the cost of processing and / or waste from work clothes and rags.

[0125] Thanks to the invention, it is easy to trigger at a reasonable cost an after-sales operation to reduce excessive oil consumption, always linked to poor engine performance, and allow the vehicle user to reduce their consumption.

[0126] The procedure is easy to implement in any garage or after-sales workshop. It allows for easy intervention on any engine with excessive oil consumption.

[0127] The invention has the advantage of not omitting any steps, injecting the same quantity of product during each manipulation, and being perfectly reproducible. The repeatability of the cleaning treatments offers a significant qualitative advantage.

[0128] In the variant using a tool, a significant cost saving is linked to the intervention of a single operator, instead of two in the other cases.

Claims

Demands

1. A method for injecting a cleaning product into a combustion chamber of an internal combustion engine cylinder, delivered from a container (200) containing a cleaning product, characterized in that said method comprises at least one engine cleaning phase (A; B; D; E) according to a predetermined sequence with predetermined durations for certain operations, followed by a final phase (C; F) of draining, fitting new components and checking, said at least one cleaning phase (A; B; D; E) comprising successively preheating the engine (A1; B1; D1; E1), then engine preparation operations (A2, A3, A4; B2, B3, B4; D2, D3, D4; E2, E3, E4) by disconnecting the battery and removing the ignition electrical circuit, a preparation operation (A6; B6; D5; E5) of said container (200), followed by a first operation (A7; B7; D6;E6) injection of said product into all cylinders for a short period of less than 7 seconds per cylinder, reconnection of the battery (A8; B8; D8; E8) and a first cranking of the starter (A9; B9; D10; E10) for a short period of less than 7 seconds, disconnection of the battery (A10; B10; DI 1; Eli) followed by a second operation (A12; B12; D14; E14) of injection of said product into all cylinders for a short period of less than 7 seconds per cylinder, a rest period (A13; B13; D16; E16) of more than 10 minutes, reconnection of the battery (A14; B14; D17; E17) and a second cranking of the starter (A15; B15; D19; E19) for a period of between 8 and 15 seconds, a battery disconnection (A16; B16; D20; E20) followed by reassembly (A18, A19; B18, B19; D21, D22; E21, E22) of the spark plug then of the ignition coil, reconnection of the battery (A20; B20; D23;E23) and continuous engine rotation (A21; B21; D24; E24) for a period exceeding 10 minutes, and several engine accelerations (A22; B22; D25; E25) lasting from 3 to 5 seconds each, up to a speed exceeding 4000 revolutions per minute.

2. The method according to claim 1, characterized in that said cleaning phase is divided into two elementary cleaning phases (A, B; D, E), comprising the same operations, with the same timing, but in the reverse order of the engine cylinders.

3. Method according to claim 1 or 2, characterized in that said first rotation at starter (A9; B9; D10; E10) has a duration of 4 seconds to 6 seconds, and in that said second rotation at starter (A15; B15; D19; E19) has a duration of 8 seconds to 12 seconds.

4. A method according to any one of claims 1 to 3, characterized in that said rest time (A13; B13; D16; E16) has a duration of between 25 minutes and 35 minutes, and in that said continuous running (A21; B21; D24; E24) has a duration of between 25 minutes and 35 minutes at a speed greater than 2000 revolutions per minute.

5. A method according to any one of claims 1 to 4, characterized in that said final phase (C; F) of draining, fitting new components, and inspection comprises a first operation (C1; F1) of preheating the engine until the fan starts, a second operation (C2; F2) of stopping the engine, a third operation (C3; F3) of removing the dipstick and filler cap, a fourth operation (C4; F4) of removing the drain plug within 4 minutes of stopping the engine, a fifth operation (C5; F5) of draining the oil for at least 20 minutes, a sixth operation (C6; F6) of changing the oil filter, a seventh operation (C7; F7) of refitting the drain plug, an eighth operation (C8; F8) of filling with the recommended quantity of new oil, a ninth operation (C9; F9) of checking the dipstick, and a tenth operation (C10; F10) of changing each spark plug, and an eleventh operation (Cil;Fl 1) clearing faults in the computer and driving test.;

6. A method according to any one of claims 1 to 5, characterized in that, after said engine preparation operations by disconnecting the battery and removing the ignition electrical circuit, an operation is carried out involving the mounting (A5; B5), on each engine cylinder, of a specific tool (100) intended for the direct injection into the cylinder of said cleaning product from said container (200) without contact with the operator, said rigid specific tool (100) being mounted as a sealing support under a high predetermined pressure exceeding 15 bar on a sealing seat of the engine and rigidly fixed

7.

8.

9. to the engine to ensure that this seal is maintained during the cleaning maneuvers, and that after the first and second phases of rotation at the starter and the disconnection of the battery, there is a removal operation (A17; B17) of said specific tool (100) allowing the reassembly of the spark plug and the ignition coil. A method according to claim 6, characterized in that said specific tool (100) comprises an expansion vessel (13) arranged to withstand any backflow of said cleaning product. A method according to claim 6 or 7, characterized in that said specific tool comprises a connecting element (2) arranged for quick-release snap-on mounting with said container (200).A method according to any one of claims 1 to 5, characterized in that, after said first injection (D6; E6) of product into the cylinder, a first operation of plugging the spark plug housing (D7; E7) with a rag takes place, and in that an operator ensures that said rag (D9; E9) is held in place during the first phase of rotation at the starter (D10; E10), after which said rag (D12; E12) is removed, in that, after said second injection of product into the cylinder (D14; E14), a second plugging of the spark plug housing with a rag (D15; E15) takes place, and in that an operator ensures that said rag (D18; E18) is held in place during the second phase of rotation at the starter (D19; E19) after which said rag is removed.

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