Removal, installation and checking glow plugs (Opel Vectra C)

1. The main elements of a glow plug are the housing and the heating element pressed into it. Due to the good starting characteristics of diesel engines with direct fuel injection, the need for preheating the combustion chambers only appears at outside air temperatures below 0°C.

Removal and installation

Z19DT(H) Engines

2. Disconnect the cable from the negative battery terminal (see Chapter 5) and remove the engine cover (see Chapter 2). On the Z19DT engine, additionally disconnect the vacuum lines running along the top of the engine.

3. Disconnect the connectors (see accompanying illustration) glow plug wiring and remove the spark plugs.



4. Installation is carried out in reverse order.

Features of Y20DTH/ Y22DTR engines

5. Loosen the mounting clamps, unscrew the 2 bolts and remove the upper section of the air intake tract, put it aside.

6. The glow plug wiring connectors are separated using a special tool (see accompanying illustration).

Checking spark plugs

7. After removal, first of all, check the spark plugs for mechanical damage - replace them if necessary.

8. The glow plug's functionality can be checked by applying 12 V to it - a working glow plug should heat up in a timely manner (be careful not to burn yourself):

• a) The power supply must be equipped with a fuse to protect against short circuits;
• b) Clamp the spark plug in a vice with soft jaws - do not forget that its working element is red-hot;
• c) After checking, let the candle cool for a few minutes to avoid burning yourself.

9. The working element of a working spark plug should glow red hot no later than 5 seconds. If it takes significantly longer to heat up the spark plug, or the tip glows only in the middle, the spark plug must be replaced.

10. For a more thorough check of spark plugs, special equipment is used, which is available at almost any service station.