Spark plugs (VW Passat B3)

The spark plug consists of an insulator, a housing, a central electrode, and a ground electrode. The central electrode is hermetically secured in the insulator, and the insulator is firmly connected to the housing. An electric spark jumps between the electrodes, which should ignite the fuel-air mixture. The starting qualities, idle properties, acceleration, and maximum speed of the car depend on the spark plug. Therefore, it is impossible to deviate from the type of spark plug prescribed by the factory, which is determined by the heat rating, without reason.

The heat rating indicates the degree of permissible thermal load of the spark plug. The lower the heat rating of the spark plug, the higher its permissible thermal load. The spark plug conducts heat better, thereby preventing pre-ignition (knocking noise when the engine is running). A spark plug with a high permissible thermal load has the disadvantage, first of all, that its self-cleaning temperature is correspondingly higher. Therefore, carbon deposits form on it faster, especially when the engine often does not reach its operating temperature during trips (city driving, short distances in winter). As a rule, "cold" candles (heat rating c 06) are installed on "hot engines" that require more power as part of a power plant.

With a copper (Cu) and, to an even greater extent, silver central electrode, the thermal conductivity and, with it, the permissible thermal load of the spark plug increase. The glow number is contained in the spark plug designation. This designation includes the following:





1)
W — thread M14x1.25 with flat seal, SW 21;
F — thread M14x1.25 with flat seal, SW 16;
M - thread M18x1.5 with flat seal, SW25;

H - thread M14x1.25 with conical seal, SW 16;
D — thread M18x1.5 with conical seal, SW21; (SW - turnkey size).

2) Heat rating. The heat scale value is indicated from 06 ("cold") to 13 ("warm"). The number 7 corresponds to a heat rating of 175 (former designation), 6 — 200.5-225 etc.

3)
A - thread length 12.7 mm, normal spark discharge trajectory;
B - thread length 12.7 mm, elongated spark discharge trajectory;
C - thread length 19 mm, normal spark discharge trajectory;
D — thread length 19 mm, elongated spark discharge trajectory;
L — thread length 19 mm, long extended spark discharge trajectory.

4) Electrode design: T - 3 ground electrodes;

5) Central electrode material: no designation - Cr-Ni - alloy; C — Ni-Cu — alloy; S — silver; P - platinum; O - standard spark plug with reinforced central electrode, For Beru spark plugs: U - copper.

[The original can be found at VWmanual]

Standard spark plugs for Passat engines

1) Only a part of the spark plugs approved for use are listed for all engines.

2) Replace spark plugs after 60,000 km.
3) Distance between electrodes: 0.9-1.1 mm.
4) When replacing spark plugs, use only the same spark plugs.
5) Distance between ground electrode and insulator: max. 0.8 mm.
6) Distance between ground electrode and insulator: max. 0.6 mm.
7) When running on Super-Plus gasoline.