3.5. Diagnostics of a condition of the engine on appearance of spark plugs
1. Normal candle.
Brown or grayish and yellow color and small wear of electrodes. Exact compliance of thermal value of a candle for the engine and operating conditions. Good advice
At replacement of candles on new establish candles with the same characteristics from among recommended by manufacturer.
2. Soot deposits.
Adjournment of a dry soot indicates a rich toplivovozdushny mix or late ignition. Causes the ignition admissions, the complicated start-up of the engine and unstable operation of the engine. Check, whether the air filter is hammered, whether sensors of temperature of cooling liquid and soaked-up air are serviceable.
Use "hotter" candle.
3. Oil deposits.
Greasy electrodes and candle insulator. The reason — oil hit in the combustion chamber. Oil gets to the combustion chamber through directing valves or through piston rings. Causes the complicated start-up, admissions in operation of the cylinder and "twitching" of the working engine. Repair of a head of the block of cylinders and piston group of the engine is necessary. Replace spark plugs.
4. Metallic raid.
Deposits on a skirt of an insulator of oxides of iron of brick-red color from anti-detonation ferriferous additives (ферроценов) to gasoline. Are postponed by an equal, dense bed. At operation of the engine with big loading under the influence of high temperature and pressure in the combustion chamber oxides are restored in the current-carrying paths of pure iron closing the central electrode on "weight". It causes admissions of ignition and, as a result, falling of engine capacity and the increased fuel consumption. The catalytic converter of the fulfilled gases which is strongly overheating at hit in it of not burned down in cylinders of the engine of gasoline can be in addition damaged. A raid practically we do not delete mechanically and does not burn out at long movement with a high speed. If this raid appears on new candles after small run, replace a filling place.
If there is no possibility at once to replace candles new, try to remove this raid, having shipped candles for ten minutes skirts of insulators in ortofosforny acid or the rust converter (contains ortofosforny acid). After that clear a raid a nonmetallic brush (it is possible an old toothbrush) and wash out candles at first water, and then gasoline.
5. The melted-off electrodes.
Early ignition. The insulator white, but can be polluted because of admissions of a spark and deposits getting on it from the combustion chamber. Can lead to engine damage. It is necessary to check compliance such as a spark plug, purity of sprays of nozzles and the fuel filter, work of systems of cooling and greasing.
6. Ashy deposits.
The light brown deposits covering with a crust the central and lateral electrodes. Are allocated from additives to oil or gasoline. Large their number can lead to isolation of electrodes of a candle, causing admissions in an iskroobrazovaniye and interruption at dispersal. If excessive deposits are formed for a short time or at small run, replace maslosjemny caps of directing valves to prevent oil hit in the combustion chamber.
If deposits are stably formed at long run, the reason as gasoline — replace a filling place.
7. A candle insulator cracked or with chips.
Detonation. It can lead to piston damage. Be convinced that the octane number of gasoline corresponds to the demanded.
8. Mechanical damages of electrodes and candle insulator.
Damages can be caused by the alien subjects which have got to the chamber of combustion, and in case of use of too long candle the piston can hook on its electrodes. It leads to candle destruction, shutdown of the cylinder and can damage the piston. Remove an alien subject from the cylinder and (or) replace a candle.