LIVAN 5511695967 SPARK PLUG
Product Specifications
| LIVAN | 5511695967 |
| MILES | ALSP059 |
The SPARK PLUG is the ignition component threaded into the combustion chamber that initiates the combustion event by generating a high-voltage electrical arc across the gap between its centre electrode and ground electrode, igniting the compressed air-fuel mixture at the precise crank angle commanded by the engine management system. The plug consists of a nickel alloy or precious metal centre electrode — platinum, iridium, or ruthenium on extended-service designs — bonded through a glass seal into an aluminium oxide ceramic insulator whose high dielectric strength and thermal conductivity profile are precisely calibrated to maintain the electrode tip temperature within the self-cleaning range of 450–870°C; below this range combustion deposits accumulate and foul the plug, above it the hot electrode becomes an ignition source for pre-ignition. The ceramic insulator sits in a steel shell with a machined thread and sealing face that seals the combustion chamber against gas leakage under peak cylinder pressures; the ground electrode is welded to the shell and positioned at the designed gap from the centre electrode tip. When the ignition coil discharges, the spark jumps the gap — typically 0.8–1.1 mm on modern engines — creating a plasma kernel whose temperature exceeds 6,000°C at its core, providing the activation energy to initiate the chain reaction of hydrocarbon combustion in the surrounding mixture.
This unit — LIVAN 5511695967 — is manufactured to OEM-equivalent specifications: thread diameter and pitch, reach (thread length), hex size, seat type (gasket or taper), heat range number, electrode gap, centre electrode material and diameter, ground electrode geometry and material, and resistor value for EMI suppression are matched to the original part. Supplied pre-gapped to OEM specification. Available wholesale from 1.34 USD, MOQ 1000 pcs, production lead time 35 days.
Spark plugs degrade through electrode gap erosion — the electrode material is progressively removed by each spark discharge, widening the gap until the ignition coil voltage is insufficient to reliably jump it; through combustion deposit fouling that bridges the gap with a conductive carbon or oil track that shorts the spark to ground; and through pre-ignition damage where a plug operating too hot causes uncontrolled combustion that melts the electrode tip. The electrode gap growth rate is the primary driver of the service interval — standard nickel plugs typically require replacement every 30,000 km; iridium and platinum plugs every 60,000–100,000 km due to the precious metal's superior arc erosion resistance.
- Allow the engine to cool before removing spark plugs from an aluminium cylinder head — the plug thread engages steel threads in the aluminium head; removing a plug from a hot aluminium head risks stripping the aluminium threads because the differential thermal expansion between steel and aluminium is at its maximum when the head is hot; always remove plugs cold or after allowing a minimum 30-minute cool-down period from operating temperature.
- Clean debris from around each plug recess before removal using compressed air — grit and carbon fragments sitting in the plug recess around the hex will fall into the open combustion chamber the moment the plug is withdrawn; even a small particle of grit landing on a piston crown or valve seat causes immediate scoring damage; blow each recess clean before cracking the plug loose.
- Verify the electrode gap of each new plug before installation even on pre-gapped plugs — shipping vibration can shift the gap on standard nickel plugs; use a wire-type feeler gauge for gap measurement; never use a flat feeler gauge on a plug with a curved ground electrode as it gives an incorrect reading; the gap specification is printed on the engine bay label or in the service data and must be matched precisely — a gap 0.1 mm wider than specification on an iridium plug significantly increases the required ignition voltage.
- Thread each plug into its bore by hand for the first three full turns before using a torque wrench — cross-threading a spark plug in an aluminium head is one of the most costly simple installation errors in engine servicing; the plug must spin freely by hand through its full thread engagement before the torque wrench is applied; any resistance felt during hand threading indicates cross-threading and the plug must be backed out and realigned before proceeding.
- Torque all plugs to OEM specification — never overtighten — gasket seat plugs typically torque to 20–30 Nm; taper seat plugs to 10–20 Nm; overtightening stretches the plug shell, distorts the ground electrode geometry, and on aluminium heads can pull the thread insert or strip the head thread requiring a Helicoil repair; undertightening allows combustion gas to leak past the seat, causing the plug to overheat from reduced heat transfer to the head.
- Install the new SPARK PLUG (LIVAN 5511695967) in all cylinders simultaneously — never replace plugs individually when performing a service interval replacement; refit all ignition coils or HT leads, start the engine and confirm smooth idle with no misfire, clear any stored misfire codes, and perform a short road test confirming smooth acceleration and no hesitation under load before returning the vehicle to service.
| Part | Reason for Combined Replacement |
|---|---|
| Ignition Coils COP coil set — one per cylinder | Ignition coils on high-mileage engines have accumulated the same heat cycling and electrical stress as the worn spark plugs — a coil that has been working at elevated output voltage to compensate for a widened plug gap has been operating beyond its design current for an extended period, shortening its remaining service life. Fitting new plugs with worn coils may not restore full performance if the coils are at the end of their service life, and a coil that fails shortly after a plug service requires the plugs to be removed again. Replacing coils and plugs simultaneously at the service interval completes the ignition system service in a single operation. |
| Valve Cover Gasket Including spark plug tube seals | On engines with recessed spark plug tubes in the valve cover, the plug tube seals are accessible and disturbed when the coils and plugs are removed. A tube seal that has failed allows oil to migrate down the tube bore to the plug electrode, causing oil fouling of the new plugs within a short operating period. Replacing the valve cover gasket set — including all tube seals — simultaneously with the spark plugs eliminates oil fouling as a recurring issue and completes the upper engine service in a single disassembly. |
| Air Filter Element OEM ref. varies by engine air box | A restricted air filter increases the fuel-air mixture richness, accelerating carbon deposit formation on spark plug electrodes and causing premature plug fouling. Replacing the air filter simultaneously with the spark plugs at the service interval ensures the new plugs operate in a correctly metered air-fuel mixture from the first start, achieving their full service life between replacements. |