Note: The DDE control unit is equipped with a fault code memory that stores faults that occur in the electrical part of the diesel injection system. In a BMW workshop, these faults can be read using the diagnostic system and rectified in a targeted manner.
Checking glow plugs
![](https://www.bmwman.ru/img/ser5/1717.jpg)
Remove engine trim covers and charge air line above glow plugs.
![](https://www.bmwman.ru/img/ser5/1718.jpg)
The glow plugs are located under the intake ports.
![](https://www.bmwman.ru/img/ser5/1719.jpg)
Unfasten glow plug connector -arrow-.
Connect the voltage tester to the positive terminal (+) at the intake manifold and then connected in series to each glow plug.
If the control lamp of the semiconductor device lights up, then the glow plug is in order. For a more accurate check, it is necessary to measure the current consumption with an ammeter (workshop work).
If the semiconductor control pump does not light up, then the glow plug is defective and must be replaced.
Withdrawal
Remove the intake manifold, see p. 63.
![](https://www.bmwman.ru/img/ser5/1720.jpg)
Unfasten wires -1- and -2-. Unscrew the glow plugs using the HAZET 4760-1 wrench and inspect.
Installation
Treat the threads of the glow plugs with CRC high-temperature copper grease available from a BMW workshop. Screw in the spark plugs, tightening torque of the glow plugs is 25 Nm.
Attention: Do not exceed the tightening torque, otherwise the annular gap between the pin and the thread of the glow plug will shrink.
Connect the connecting wires of the glow plugs, tighten the fastening nuts to a torque of 5 Nm.
Replace all gaskets and tighten intake manifold to cylinder head to 25 Nm. Also tighten oil filter support and exhaust gas recirculation line to intake manifold to 25 Nm.
Install the engine trim covers and charge air pipe above the glow plugs.
Glow plugs with burnt pin
Burnt glow plug pins are often the result of malfunctioning injector nozzles. This type of damage cannot be attributed to flaws inside or outside the glow plug.
![](https://www.bmwman.ru/img/ser5/1721.jpg)
If the test reveals glow plugs with a burnt pin -arrow-, it is not sufficient to simply replace the glow plugs. In this case, it is necessary to check the respective nozzles for jet geometry, opening and closing of the atomizer needle, injection pressure and tightness (workshop work).