Audi A4

since 1994 of release

Repair and car operation

A4 Audi
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ exhaust System
+ cooling System
+ Fuel tank and fuel pump
+ Air filter and absorption channels
+ injection System
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
- Ignition system
   That provides ignition
   When there is an ignition of a fuel and air mix?
   Different systems of ignition
   So there is an ignition spark
   Executive body
   System brain
   The signals arriving in the control unit
   Detonation adjustment
   Be careful in the address with ignition
   Works on ignition system
   Search of malfunctions in ignition
   Ignition distributor
   Knot of a high voltage
   Replacement of spark plugs
   Right choice of spark plugs
   Check of the moment of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics

Replacement of spark plugs

For replacement of spark plugs in the engine in capacity of 92 kW it is necessary to disconnect the socket (1) on the terminal cascade of capacity and to unscrew the terminal cascade together with ignition coils. Shooters showed screws. At installation consider an order of laying of a wire: the wire from the back coil (2) goes to the 2nd cylinder (4); a wire from the forward coil (3) – to the 1st cylinder (5).

The plan of maintenance provides replacement of candles through each 60 000 km or every three years – that comes earlier. The time interval prevents emergence of defect at the expense of aging at small run.

Audi provides very big interval in maintenance which can be observed only in case of use of admissible types of candles. Therefore there is occasion no it to extend even more. On a working condition of system of ignition it is necessary to pay special attention in case in cars there is a catalytic converter – we already spoke about it.

It is necessary to examine the dismantled candles critically: further you will read, about what tells «a face of a candle».

If sometimes candles are unscrewed for check: it is desirable not to clean candles a hand. It harms to an insulating layer of an intermediate electrode of a spark plug (стеатит).

Dismantle of spark plugs


    Engine of 1,8 l and six-cylinder engine: dismantle an engine cover. Engine of 1,8 l in capacity of 92 kW: unscrew and take out ignition coils with the terminal cascade of capacity; remove sockets of candles. Engine of 1,8 l in capacity of 110 kW: unscrew and remove separate coils of ignition. At dismantle of sockets of coils of ignition do not pull a wire, and undertake the socket. Unscrew spark plugs and combine them in sequence of cylinders in order that it was possible to draw conclusions on a condition of a candle of the corresponding cylinder. If candles sit very strongly, do not apply force, differently it is possible to strip a thread candles in a head of the block of the cylinders, made of light metal. Warm up the engine and now unscrew candles. At installation do not screw up densely cold candles in the warmed-up head of the block of cylinders, differently they will sit then, as riveted. Spark plugs should be screwed up on 30 Nanometers. If there is no near at hand a dinamometrichesky key: Screw up a candle so that the sealing ring adjoined – it cannot be turned without application of force a hand, a key for candles. To Dovintita now a new candle a special key precisely on a quarter of a turn is stronger. The candle which was in the use, it is possible довинчивать only approximately on 15 °.

Spark plugs should be tightened on 30 Nanometers. If near at hand there is no dinamometrichesky key: screw up a candle so that the sealing ring (shooter) adjoined – in this case it cannot be tightened a hand or a key without application of force. Now, if a candle new, tighten it a key precisely on a turn quarter. If the candle was in the use, turn it a key only approximately on 15 °, it is enough of it.

 Councils: To increase sliding of a carving of a spark plug, you can наскрести in rounds a little graphite from a soft simple pencil or a little grease them with medesoderzhashchy greasing. Oil or greasing "will bake" a spark plug in a carving of a head of the block of cylinders.

«Person of a spark plug»

Spark plugs in a certain degree are witnesses of process of combustion in the engine. («The person of a candle») it is possible to determine by appearance of a top of a candle, the engine how optimum works. Previously it is necessary to warm up thoroughly the car on the rural road or on the highway. Check after movement on short distance can lead to the wrong conclusion. Look at an insulator top with an average electrode and on lateral electrodes:

    Top of an insulator of light gray or brownish color: the correct installation of system of injection, the engine works economically. Strong deposits: the reason can be in additives in engine oil, either in fuel, or in the raised consumption of oil. Change oil or fuel brand. Deposits of black color similar to soot: at the expense of frequent movement on short distances the candle does not reach self-cleaning temperature, the wrong kalilny number. Top of an insulator of whitish color: the moment of ignition is too strongly shifted towards "advancing", electronic adjustment of the moment of ignition or a detonation sensor does not work. The melted-off sites on an average and lateral electrodes: nakalny ignition as a result of a deposit in the combustion chamber, the peregrety valves, incorrectly established point of ignition, defective adjustment of a point of ignition or stagnation of heat as a result of insufficient cooling. Destruction of a top of an insulator, at an initial stage appreciable in the form of hair cracks: detonation combustion because of fuel of poor quality, the wrong installation of ignition, defective adjustment of a point of ignition, a defective sensor of the detonation, insufficient cooling of the engine or pauperization of a fuel and air mix at the expense of collateral air. Yellowish brilliant layer on an insulator top: deposits at the expense of additives in gasoline and engine oil which at sharp full load of the engine passed to a liquid state were formed and became electrowire and as a result – interruptions in ignition. At trips on short distances week you should not subject the engine to full loading at once. Butter layer on electrodes and an internal surface of candles: defect of rings of the pistons, directing valves or laying of cores of valves. If in appearance of a spark plug any features are not appreciable, but the engine badly is started or twitches, nevertheless the reason can be in candles. During start of the cold engine invisible cracks in a ceramic insulator can be filled with condensate of fuel which takes away an ignition spark. Under the pressure of a candle too can refuse, though in the dismantled condition it is visible, as the spark slips. In a doubtful case replace.

Distance between electrodes

The fuel and air mix and exhaust gases promote corrosion of metal electrodes of spark plugs. And the high voltage at a proskakivaniye of a spark tears off from them the smallest particles of metal therefore the distance between electrodes of spark plugs over time increases. In the presence of candles with three electrodes the spark of ignition can "find" the shortest way. Therefore almost it is not required to turn in electrodes.