Diagnosis of Faults

Appearance of the cape:

Cable contamination due to oil leakage, cleaning products or products for detecting leakage current. The cable may have a damp appearance. (presence of oil) or dried out, causing loss of cable elasticity.

Problems:

Misfire;

Higher probability of flash over occurrence.

Causas:

1. 1. Engine oil leak;
2. 2. Use of solvents for engine cleaning;
3. 3. Use of Leakage Current Detection Products;

Solutions:

For Cause 1, fix engine oil leaks;

For Cause 2, avoid the use of solvents in engine washing;

For Cause 3, avoid using spray to detect leakage current;

for all causes, replace the cables with those specified in the NGK application table.

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Coil Aspect:

Coil terminal rubber degradation;

Coil rubber drying.

Trouble:

Misfire;

Flash over between spark plug and coil;

Causes:

1. 1. Degradation of terminal rubber due to time of use;
2. 2. Terminal contamination by lubricating oil.
3. 3. Excessive heating in the head region;
4. 4. Use of chemical products in engine washing;

Solution:

For Cause 1, perform preventive maintenance on the ignition system, replacing the components if the rubber shows dryness;

For Cause 2, check and correct any engine oil leaks;

For Cause 3, check any engine heating problems, correct if necessary;

For Cause 4, avoid the use of chemicals in engine washing.

for all cases, replace the ignition coil with the correct model, referring to the NGK application table.

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Appearance of the candle:

Coal waste deposits (black color) at the tip of the candle, is one of the main problems encountered with spark plugs.. Coal is formed by unburned or excessively injected fuel. Fuels like ethanol (alcohol) and CNG (vehicle gas) do not generate coal residue. Waste is common with the use of gasoline.

Problems: Coal is a conductor of electrical energy and causes loss of spark plug insulation, generating misfire.

difficulty in starting, mainly with a cold engine;

Increased fuel consumption;

Misfires;

Increased levels of polluting gases;

black smoke in exhaust;

Black waste in exhaust, as a dry feature.

Causes:

1. 1. rich mix;
2. 2. Lack of tightness in fuel injectors;
3. 3. Canister Bleed Valve Locked Open;
4. 4. Canister saturated with liquid fuel;
5. 5. Sensores MAP, MAF, engine temperature, air temperature and oxygen sensor in poor condition;
6. 6. Fuel line pressure too high;
7. 7. Use of unspecified injectors for vehicle or other fuel (flex);
8. 8. Application of electro erosion on injectors or corrosion due to the use of poor quality fuel;
9. 9. Lack of thermostatic valve;
10. 10. Use of poor quality fuel;
11. 11. Application of incorrect spark plugs or with incorrect clearance;

Solutions:

Para as causas de 1 a 8, Fix Injection System Problems;

For Cause 4, in addition to fixing the canister problem, fuel the vehicle until the pump turns off automatically;

Para a causa 9, fix cooling system problems;

Para a causa 10, use good quality fuel;

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the candle:

Coal residue at the tip of the candle, but with a damp appearance (wet).

Problems:

Loss of spark plug insulation

difficulty starting;

Misfire;

Lubricating oil consumption;

Causes:

1. 1. Valve guide clearance above specified;
2. 2. Valve guide retainer lacking tightness,
3. 3. wear rings, excessive clearance between rings, ring break.
4. 4. lack of honour, scratched or oval cylinder;
5. 5. Excessive pressure in oil pan;
6. 6. Clearance in turbine shaft;
7. 7. Lubricating oil contamination;
8. 8. Oil level above specified;
9. 9. Using oil with incorrect viscosity;
10. 10. Use of poor quality or contaminated fuel;

Solutions:

Para as causas de 1 a 8, correct the problems that are increasing the consumption of lubricating oil;

Para a causa 9, use specific lubricant for the engine;

Para a causa 10, use good quality fuel;

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the glow plug:

Breakage of the glow plug bulb by thermal shock.

Problems:

Burning the glow plug;

Fault lamp lit on panel;

Cold start difficulty;

White smoke on cold start;

black smoke in the engine.

Causes:

1. 1. Lack of tightness of the injectors;
2. 2. engine oil burn;
3. 3. Oil leakage from the turbine;
4. 4. Water infiltration into the combustion chamber;
5. 5. Condensation of water in fuel.

Solutions:

For Cause 1, check the tightness of the injectors, correcting if necessary;

Para a causa 2 e 3, check the condition of the engine and turbocharger;

Para a causa 4 e 5, check fuel condition and moisture separator filter;

for all causes, replace the glow plug as per NGK application table.

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Appearance of the candle

Reddish coloration at the tip of the ceramic insulator, may have flashover marks (misfires).

Problems:

difficulty in starting;

Acceleration Resume Failed;

Increased fuel consumption;

Increased levels of pollutant emissions;

Causes:

1. 1. Use of poor quality fuel;
2. 2. Use of iron oxide in fuel;

Solutions:

Para as causas 1 e 2, use good quality fuel.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance:

Corrosion in the area of ​​the spark plug thread and/or internal part of the metallic castle.

Problems:

Locking the spark plug thread in the head;

Damage to the head thread;

Difficulty in removing the candle;

Disruption of the candle's castle in the removal;

Misfires.

Causes:

1. 1. Use of wire brush to clean spark plug thread, removing the protective bath from the metal part;
2. 2. Infiltration of coolant into the combustion chamber;
3. 3. fuel usage (ethanol) shoddy.

Solutions:

For Cause 1, do not use abrasive materials to clean spark plugs;

For Cause 2, check for possible leakage of coolant into the combustion chamber;

For Cause 3, use good quality fuel.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the cape:

Cut in protective cover or sealing sleeve.

Problems:

current leakage;

Misfire.

Cause:

Inappropriate tool use for cable removal, causing a cut in the rubber (incorrect handling).

Solutions:

Replace the cables with those specified in the NGK application table.

Avoid using sharp tools to remove cables.

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Appearance:

Deformation or misalignment of the central and lateral electrode;

Breaking the ceramic insulator;

Kneading or deformation of the metal castle.

Problems:

malfunction;

Cylinder compression loss.

Causes:

1. 1. Breakage of parts that make up the combustion chamber;
2. 2. excessive heat (heat stress) in the combustion chamber;
3. 3. Material fatigue of moving combustion chamber components;
4. 4. Abnormal combustion phenomena such as pre-ignition and detonation;
5. 5. Mix depletion;
6. 6. Use of poor quality fuel;

Solutions:

For Cause 1, check and correct any engine wear problems;

For Cause 2, check the cooling system and any heat exchange problems;

For Cause 3, check moving engine components for wear and alignment., avoiding the reuse of wear components;

For Cause 4, check for hot spots in the combustion chamber, residues and/or deformation or impact points;

Para causa 5, in the case of turbo engines or with high compression ratio, check air/fuel mixture stoichiometry in all rpm ranges varying engine load;

For Cause 6, use good quality fuel;

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the glow plug:

Clearance between glow plug body and bulb.

Trouble:

Early burning of the glow plug.

Cause:

Excessive tightening torque on the glow plug.

Solution:

When installing the glow plug, apply the specified tightening torque.

Check that there has been no damage to the head seat, repairing if necessary.

Replace glow plug according to NGK application table.

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Coil Aspect:

Coil has melting on electrical connector pins and/or coil melting.

Trouble:

Misfire;

Coil melting;

Smoke in the engine compartment;

Cause:

1. 1. Bad contact between harness connector and ignition coil connector;
2. 2. Connector clearance;
3. 3. Lack of connector lock;
4. 4. Whip Rust (power cables) of the coil and/or poorly sized wire (in cases of wiring repairs);
5. 5. Supply current too high;

Solution:

For causes 1 to 3, replace vehicle harness connector.

For Cause 4, replace or repair vehicle harness. Use specific wires that support the supply current and temperature;

For Cause 5, check the coil supply current, too high supply current causes heating of wires and connector;

for all cases, replace the ignition coil with the correct model, referring to the NGK application table.

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Appearance of the glow plug:

Deformation of the glow plug bulb during installation.

Problems:

Glow plug does not sit on head;

Exhaust gases.

Cause:

Residue (soot and carbon) in the glow plug housing.

Solution:

Clean the glow plug housing in the head.

Replace glow plug according to NGK application table.

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Appearance of the candle:

Spark plug tip soaked in fuel or lubricating oil.

Problems:

Misfire;

difficulty in starting;

Irregular slow gait;

Increased fuel consumption;

Increased emissions.

Causes:

1. 1.Vazamento de óleo na tampa de válvulas e acumulando no duto da instalação da vela;
2. 2.Falta de estanqueidade de injetores ou com vazão muito acima do especificado;
3. 3.Tempo de injeção muito alto;
4. 4.Folga entre eletrodos da vela muito fechada;
5. 5.Isolador da vela de ignição trincado na instalação;

Solutions:

For Cause 1, correct any leaks in the valve cover;

For causes 2 and 3, fix the problems related to the injection system;

For Cause 4, check gaps between spark plug electrodes before installing;

For Cause 5, replace the spark plug using a suitable tool and applying the specific tightening torque.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the glow plug:

Gas exhaust marks by glow plug;

color change;

Glow Plug Overheating.

Problems:

Gas exhaust by the glow plug;

Overheating damage;

loss of performance;

Damage to vehicle harness;

Fault lamp lit on panel;

Cold start difficulty;

White smoke on cold start.

Causes:

1. 1. Lack of tightening torque at installation;
2. 2. Residue on the glow plug seat;
3. 3. Deformed head housing seat;
4. 4. Incorrect glow plug application.

Solutions:

For Cause 1, apply the correct tightening torque;

For Cause 2, remove debris before installing the glow plug;

For Cause 3, check and correct the glow plug seat in the head;

For Cause 4, apply the correct glow plug;

for all causes, replace the glow plug as per NGK application table.

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Appearance of the candle:

Deformation of the metallic castle (stretching) the castle may or may not break. In cases where there is no complete breakage of the metallic castle, the insulator may loosen due to the loss of pressure in the sealing washer.

Problems:

Breakage of the metallic castle in the installation of the candle.

Breakage of the metallic castle when the candle is uninstalled.

Ceramic insulator release.

Causes:

1. 1. Torque application above specified.
2. 2. Oxidation between the cylinder head thread and spark plug.

Solutions:

For Cause 1, apply the correct tightening torque as per the motor manufacturer's specification or NGK torque table.

For Cause 2, do not clean candles using a wire brush, this practice removes the protective bath causing the metal castle to oxidize.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the candle:

Rounding of central or lateral electrodes, loss of sharp corners in the electrodes and increased clearance between them.

Noble metal candles such as platinum and iridium wear is barely noticed on visual inspection, the electrode has oxidation points and material deposits on the electrodes.

Problems:

Increased sparking voltage;

Difficulty in cold starting;

Acceleration failures and speed resumption;

Damage to the ignition system and reduced useful life of ignition coils;

Misfires using CNG (vehicle gas), back-fire (intake manifold overflow).

Increased levels of pollutant emissions;

Flash-over, high voltage passage on the outside of the spark plug;

Consumption increase;

Causes:

1. 1.Desgaste natural da vela;
2. 2.Final de vida útil.

Solutions:

Para as causas 1 e 2, replace spark plugs according to vehicle maintenance manual, if you don't have, revise as velas anualmente ou a cada 10.000km para automóveis e 3.000 km for motorcycles. Replace if necessary.

For severe use, in heavy traffic situations, frequent matches, etc, replace the spark plug more often;

Use with CNG (vehicle gas) is considered severe use, it is necessary to change more often.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the candle, cable and coil:

Sail: Dark vertical marks between terminal pin and metal castle, caused by the passage of electric current on the outside of the spark plug.

Cape: Vertical marks on the cable insulation rubber, caused by the passage of electric current.

Coil: Vertical marks on the coil insulation rubber or between the high voltage terminals, caused by the passage of electric current.

Problems:

Misfires, especially at higher engine torque rotations, which can generate overflows in the intake manifold in case of CNG use.

Consumption increase;

Increased levels of pollutant emissions;

Causes:

1. 1. Replacing only one component affected by flashover;
2. 2. Presence of contaminants between the surface of the spark plug and cable or spark plug and ignition coil;
3. 3. lean mixture;
4. 4. Excessive wear of spark plugs;
5. 5. Cable or coil with dry or inelastic rubber terminal;
6. 6. Compression ratio or turbo pressure too high;
7. 7. delayed ignition timing;
8. 8. Incorrect candle application, cables and coil;

Solutions:

For Cause 1, replace candles, cables and coil simultaneously;

For Cause 2, clean your hands, avoiding oil residue, greases and solvents in ignition components;

For Cause 3, check the correct operation of the injection system;

For causes 4 and 5, follow the maintenance plan specified by the engine manufacturer. If you do not have the maintenance plan, the recommendation is to inspect every 10.000km and change every 3 years or 60.000Whichever comes first;

For Cause 6, check compression ratio or turbo pressure, correcting if necessary;

For Cause 7, in CNG systems (gas) and programmable injection system, check the correct ignition timing;

For Cause 8, replace the candles, cables and ignition coil by those specified in the NGK application table.

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Appearance of the cape:

When replacing the ignition cable, which is apparently normal, motor fails with new cable. There may have been a hole in the spark plug terminal, due to misalignment with the spark plug at the time of installation.

Trouble:

Misfire.

Cause:

Misalignment between spark plug and cable at installation.

Solution:

Install the cable correctly, according to spark plug alignment.

Replace the cables with those specified in the NGK application table.

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Appearance of the candle:

The crack can be visible or not. The visible ones are characterized by a crack in the candle's ceramic insulator. Non-visible can be detected when there is an insulator misalignment or in a high pressure spark test.

Trouble:

Misfire with the new spark plug.

Causes:

1. 1. Spark plug wrench misalignment at installation (incorrect handling);
2. 2. Use of bad or unspecified key;

Solutions:

Para as causas 1 e 2, use proper tools and in good condition, ensuring full coverage of the hexagonal part of the candle and avoiding contact with the ceramic part.

OBS: Due to the difficulty of some specific engines, it is necessary to use a special tool to install the spark plugs.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the candle:

Yellow to brown stains on the outside of the ceramic insulator near the metal castle.

Trouble:

Does not generate engine problems.

Cause:

With the passage of electric current through the spark plug, an electric field is generated that attracts oil particles, fuels and other volatile products that are suspended in the engine compartment. These particles adhere to the surface of the insulator forming surface stains on the part..

Solutions:

Correct any oil or fuel leaks in the engine;

Avoid the use of volatile solvents in the engine safe.

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Coil Aspect:

High voltage coil terminal or connector with oxidation.

Problems:

Misfire;

High resistance in the secondary of the coil;

Excessive heating in the region of the terminals;

Melting the Wire Harness and Coil;

Rust of new cables or spark plug terminal pin.

Causes:

1. 1. Water infiltration or chemical attack on high voltage terminals;
2. 2. Bad contact between cable and ignition coil and/or spark plug and ignition coil;

Solution:

For Cause 1, avoid the application of chemicals and/or solvents when washing engines.

For Cause 2, ensure a perfect connection between cable and coil and/or between spark plug and ignition coil. Replace ignition coils and ignition cable simultaneously, in the case of coils applied directly to the spark plug, replace spark plugs and ignition coils simultaneously;

for all cases, replace the coil, cables and spark plugs of the correct model, referring to the NGK application table.

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Appearance of the cape:

Connection terminal with oxidation.

Trouble:

Misfire;

High contact resistance.

Causes:

1. 1. Bad connection between cable and spark plug or cable and coil, in this case there is formation of ozone that is highly oxidizing;
2. 2. Water or moisture infiltration;
3. 3. Chemical attack.

Solutions:

For Cause 1, make sure the cable is well connected to the spark plug and ignition coil;

For causes 2 and 3, avoid the application of solvents, chemicals and water in ignition cables.

for all causes, replace the cables with those specified in the NGK application table.

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Coil Aspect:

Melting epoxy resin, coil body deformation and coil overheating.

Trouble:

Misfire;

difficulty starting;

Coil Overheating - With Coil Overheating, smoke may occur, the coil material is self-extinguishing, that is, when cutting the coil power it does not ignite;

Causes:

1. 1. Incorrect coil application;
2. 2. Problem Injection Module Command Drive;
3. 3. Dwell time, loading time, very high;
4. 4. Bad contact in the coil ground and/or electrical system ground;
5. 5. Supply voltage too high;
6. 6. Coil command signal out of specification;
7. 7. Excessive spark plug wear;

Solution:

For Cause 1, replace the ignition coils with the correct type;

For causes 2 and 3, check the injection module command drive. There are two types of coils, with ignition module attached and without ignition module attached. If the coil has an ignition module, the injection module is responsible for sending a command signal to the coil, this signal must be checked for format and duration.. If the coil does not have an ignition module, the feed is commanded directly by the injection module, in this case, check the injection module command. If necessary, repair the injection module command drive;

For causes 4 and 5, check the food, coil grounding and electrical system grounding;

For Cause 6, check the dwell time and coil command signal if they are compatible with the applied coil;

For Cause 7, check spark plug wear, heavily worn spark plugs need more tension for sparking, increasing coil stress;

for all cases, replace the ignition coil with the correct model, referring to the NGK application table.

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Appearance of the candle:

Side electrode breakage in the region above the electrode weld.

Problems:

Misfire;

power loss;

Difficulty starting the engine.

Causes:

1. 1.Vibração anormal no motor;
2. 2.Falta de torque de aperto;
3. 3.Fenômenos de combustão anormal como detonação no motor;
4. 4.Resíduo na câmara de combustão;
5. 5.Combustível de má qualidade.

Solutions:

For Cause 1, check sources of abnormal engine vibration;

For Cause 2, apply the tightening torque recommended in the NGK application table;

For Cause 3, check ignition calibration in case of recalibration of injection systems or use of programmable systems.

For Cause 4, check the presence of residue in the combustion chamber, if necessary, clean the residues in the chamber;

For Cause 5, use good quality fuel.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Coil Aspect:

Breakage in the body region or high voltage tower.

Trouble:

electric current leakage;

Misfire;

Fixing difficulty.

Causa:

1. 1.Drying of the coil body;
2. 2. Impacts;
3. 3.Excess torque in the coil clamping;
4. 4.Misalignment in coil clamping.
5. 5.Misalignment in the installation or removal of the ignition cables;

Solution:

For Cause 1, turn the cable to detach from the coil terminal;

For Cause 2, avoid impacts on the coil body;

For Cause 3, apply the correct tightening torque when installing the coil;

For Cause 4, ensure perfect alignment between the clamping face and a coil;

For Cause 5, ensure alignment between cable and coil terminal;

for all causes, replace the ignition coil with the correct model, referring to the NGK application table.

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Appearance of the glow plug:

Presence of residue in the form of a ring near the region where the glow plug settles.

Problems:

Difficulty installing the glow plug;

Lack of glow plug sealing;

Gas exhaust by the glow plug.

Causes:

1. 1. Engine oil seepage into the combustion chamber;
2. 2. Oil leakage from the turbine;
3. 3. Incorrect application.

Solution:

Para as causas 1 e 2, check the condition of the engine and turbocharger, repairing if necessary.

For Cause 3, clean and check the glow plug housing and seat, repairing if necessary.

for all causes, replace the glow plug as per NGK application table.

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Appearance of the cape:

Cables and their terminals are produced based on high performance polymers, but with constant heating they show dryness and loss of elasticity.

Problems:

Misfire;

Higher probability of flash over occurrence.

Causas:

1. 1. Lack of preventive maintenance;
2. 2. overheating;

Solutions:

For Cause 1, perform preventive maintenance as specified by the assembler or engine manufacturer. Substitua os cabos de ignição a cada 3 anos ou 60.000km;

For Cause 2, check the cooling system. In the case of cables that are positioned next to the exhaust manifold, check for obstruction or cracks in the exhaust manifold and lack of heat deflectors.

for all causes, replace the cables with those specified in the NGK application table.

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Appearance of the glow plug:

Thread breakage in the fastening region or in the harness connector.

Problems:

Difficulty in fixing the harness;

Thread breakage in the terminal region;

Difficulty in removing the glow plug.

Cause:

Application of excessive tightening torque.

Solution:

Applying the correct tightening torque.

Replace glow plug according to NGK application table.

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Appearance of the cape:

Release of the metallic cable connector, tear in the ignition cable protective cap.

Problems:

Installation difficulty;

High electrical resistance or discontinuity.

Causes:

1. 1. Cable inclination when uninstalling;
2. 2. Pull the cable by the wire when uninstalling.

Solutions:

For Cause 1, pull the cable in line with the spark plug,

For Cause 2, remove the cable through the terminal, turning the terminal to take off the sail;

for all causes, replace the cables with those specified in the NGK application table.

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Appearance of the candle:

Deformation or melting of spark plug electrodes, change in the color of the metallic castle (darkening) and ceramic degradation indicate candle overheating..

Problems:

Misfire;

Engine efficiency loss.

Causes:

1. 1. Cooling System Problems;
2. 2. Very high compression rate;
3. 3. Residue in combustion chamber or hot spots in combustion chamber;
4. 4. Use of helicoil-type build-up thread or filler materials with different heat exchange coefficient on the spark plug thread;
5. 5. Air/lean fuel mixture;
6. 6. Knock sensor damaged or incorrect torque;
7. 7. Excessive spark timing advance;
8. 8. Excessive turbo pressure;
9. 9. High intake air temperature;
10. 10. Obstruction of exhaust system;
11. 11. Low octane fuel usage;
12. 12. Lack of spark plug tightening torque;
13. 13. Elongation of the metallic castle due to excessive torque;
14. 14. Incorrect spark plug application;

Solutions:

For Cause 1, check and fix cooling system problems;

Para as causas de 2 a 4, check and fix engine-related problems;

Para as causas de 5 a 8, check and correct problems related to the injection and turbocharging system;

Para as causas 9 e 10, check and correct problems related to the admission system, turbo heat exchanger (intercooler) and exhaust;

Para a causa 11, use good quality fuel;

Para as causas 12 a 14, apply the spark plug according to the NGK application table with the correct tightening torque.

for all causes, replace spark plugs with those specified in the NGK application chart.

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Appearance of the glow plug:

Damage and deformation of glow plug bulb.

Problems:

Burning the glow plug;

Fault lamp lit on panel;

Cold start difficulty;

White smoke on cold start.

Causas:

1. 1. Glow plug overheating due to excess voltage;
2. 2. Faulty cold start control system;
3. 3. Incorrect application.

Solutions:

For Cause 1, check the supply voltage of the glow plugs;

For Cause 2, check the cold start control system;

For Cause 3, apply the correct glow plug for the engine.

for all causes, replace the glow plug as per NGK application table.

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Coil Aspect:

Ignition coil has cracks in body or epoxy resin.

Trouble:

electric current leakage;

Misfire;

Difficulty starting the engine;

Fixing difficulty.

Cause:

1. 1. Abnormal engine vibration;
2. 2. overtemperature;
3. 3. Thermal shock;
4. 4. Coil body twist;

Solution:

For cause 1, check for abnormal engine vibrations, bearings (cushion) engine support brackets broken or out of specification;

For Cause 2, check any problems in the engine's cooling system. Check that there is no lack of heat deflector or coil spacers and exhaust manifolds. Check that there is no clogging or obstruction of the exhaust and catalyst;

For Cause 3, avoid thermal shocks such as application of cold water when washing engines;

For Cause 4, avoid twisting the coil body during installation;

for all cases, replace the ignition coil with the correct model, referring to the NGK application table.

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