Glow plugs have a long lifespan, however they do gradually deteriorate due to wear and tear. So how do you know if a set of glow plugs needs replacing?
Bujía incandescente per a Isuzu 8-97043744-0 8-94387612-1 8-97044037-0 Pi-59 84mm 11v
En aquest article, analitzem sis signes habituals que indiquen que les bugies incandescents podrien estar defectuoses o danyades.
Something's wrong: the engine warning light
The engine warning light on the dashboard is often the first clue that something is wrong. Vehicles displaying this light should be taken to an authorised workshop for proper diagnosis and service as soon as possible. A number of faults can cause the engine warning light to illuminate – below, we outline the clues which point to faulty glow plugs.
Inici difícil
A hard starting engine is the most common indicator of damaged glow plugs. In cold conditions, without correctly functioning glow plugs, the combustion chamber may not reach the right temperature to ignite the fuel and start the engine. If there are no problems with the fuel or the battery, then glow plugs should be checked.
El motor falla
El procés de combustió en motors dièsel requereix una alta taxa de compressió, combustible injectat en el moment correcte i en la quantitat correcta. Això encén el gasoil, donant lloc a la combustió. Els errors d'encesa poden ser causats per problemes amb la qualitat del combustible, la compressió i la injecció de combustible.
Ralentí brusc
If one or more glow plugs have burned out, are carbon fouled or damaged, the engine will become progressively harder to start as temperatures drop and will idle roughly and produce white smoke from the exhaust for several minutes once it finally starts. If all the glow plugs are burned at their tips, check the fuel injection timing.
Disminució de l'eficiència del combustible
Temperature and fuel usually determine fuel efficiency, not glow plug performance. However, in some cases, glow plugs do have a role to play.
Based on local climate, diesel may be blended with specific additives during the cold months to lower its freezing point. The blended fuel will most likely have a lower energy content and provide reduced fuel efficiency. Engine operating temperatures should be adjusted to ensure all the injected fuel is completely burnt. Glow plugs help to provide the additional heat in the combustion chamber.
Bujía incandescente per a Isuzuv 5-81410044-0 Pi-53 95 mm 20,5 v
If the required temperature is not reached due to faulty glow plugs, the engine's performance will be weakened, and it will have to work extra hard to meet the demands of the road. The vehicle's fuel efficiency will be negatively affected.
Si el cotxe ha mostrat altres símptomes enumerats aquí i també comença a mostrar una eficiència de combustible reduïda, s'ha de portar a un taller autoritzat per a un diagnòstic i servei adequats tan aviat com sigui possible.
Fum blanc
White smoke usually occurs when there is not enough heat to burn the fuel. The unburnt fuel particles travel out of the tailpipe as smoke and typically produce a rich fuel smell. It's not unusual to see white smoke from the exhaust during cold weather, until the engine has warmed up.
Bujía incandescente per a Isuzuv 8-94439218-0 Pi-55 89mm 5v
Les bugies incandescentes danyades o un mòdul de control de la bujía defectuós poden provocar fum blanc a l'arrencada del motor. També hi ha moltes altres causes possibles per a un excés de fum blanc, com ara la baixa velocitat d'arrencada del motor, la baixa compressió i l'aire al sistema de combustible. Si el fum blanc encara és visible després que el motor s'hagi escalfat, és possible que el motor tingui un o més injectors defectuosos, un temps d'injecció retardat o una bomba d'injecció desgastada.
Fum negre
Black smoke is caused by an imbalance in the air-fuel ratio – too much fuel and not enough air. This means either too much fuel is being added to the mix or there is not enough oxygen being supplied to burn the fuel. Faulty glow plugs may disturb the sensitive diesel combustion process, which in turn might result in the engine producing black smoke from the tailpipe. This is a warning sign that something is wrong either with the glow plugs or other vital components of the combustion process.
