Checking glow plugs
1. Unscrew the glow plug wires.
2. Connect an ohmmeter in series to each glow plug and check for a short circuit between the spark plug contact and the cylinder block.
3. If the resistance is not zero, the glow plug is defective and must be replaced.
4. Remove the defective glow plug. Screw in a new glow plug (3) and tighten with a force of 20 Nm. Connect wire (2) and tighten the nut (1).
Attention! Do not exceed the specified tightening torque, otherwise the glow plug may be damaged and the spark plug will fail prematurely. Be careful not to get oil or fuel on the spark plug. For burnt rods, follow the instructions.
Attention! If no defect is found, although the engine does not start well, inspect the glow plugs externally with the glow turned on. To do this, remove the injection nozzles and watch the glow plugs through the holes when warming up.
5. When glow plugs with burnt heating rods are found (arrow), it's not enough just to replace them. In this case, it is also necessary to check the injectors for injection pressure and tightness.
6. Burning of glow plugs is often the result of defective injectors. Such damage should not be attributed to an internal or external defect in the glow plug.
Checking the glow plug relay
1. Remove the glow plug relay connector.
2. Connect the relay to the battery with two wires. Connect an ohmmeter and check if the terminals are closed.
3. If the terminals are not closed, the relay must be replaced.