This page has been translated with google translate, there may be errors in the stories.

Glow Plug Basics.

Front chamber diesels usually have a glow plug because otherwise too little heat will enter the front chamber when starting to properly ignite the fuel.

The cold cylinder wall and the intake air are too cold for the fuel to self-ignite. The air must therefore be warmed up, because the required ignition temperature will not be reached without the heat from the glow plug.

To give your fuel and the air present the correct ignition temperature, a glow plug has been placed in the front chamber that can reach more than 800 degrees. This preheating is done before you start the engine and takes a few seconds to 30 seconds, depending on whether you have fast heaters or slow heaters.

Installation and removal of a glow plug.

1 Clean the area well.

2 Remove the glow plug with a warm engine if possible.

3 Unscrew the old glow plug.

4 Remove dirt and rust in or near the spark plug bore.

5 Screw in new or checked glow plug by hand as far as possible.

6 Retighten the glow plug with a torque wrench.

Measure voltage on the glow plugs or glow plug relays.

With a multimeter you can measure the voltage at the connection of the glow plugs in relation to the ground and this value can be compared with the factory regulations. If you measure a deviating value, this can have various causes, such as bad contacts, a defective pre-glow relay or a defective glow plug. The measurement is done with a multimeter and if you want to measure the glow plug relay you have to pull it partially out of the terminal block. This way you can measure the stresses in relation to mass. You can continue to measure for resistance and if the resistance is infinite, often 0 or - (negative), the glow plug is defective and must be replaced.

Tip!!! Immediately replace all glow plugs if one is broken.

Check the glow plug connections.

The measurement of a glow plug and the connection is best done with the spark plug still in the block. Remove the negative from the battery and the connector from the spark plug itself that goes to the glow plug relay. If you are going to measure with a multimeter, it is useful if it is digital and of a better quality, so one from a hardware store of two decades is not accurate enough for this job. The resistance of a glow plug must be less than 1 and may not be 0 because then the glow plug is not in order and you have a closure. If you have a 0 or - on the digital multimeter, you have an infinite resistance and you have an interruption in the glow plug.

Visual inspection of the glow plug.

1 Check the connection to the spark plug for corrosion and dirt.

Look at the glow part. A properly working spark plug is light gray, the spark plug burns itself clean.

Glow plugs 2 and 4 in the picture are broken.

Cylinder head with glow plug.

Glow plug connection diagram

With a glow system that is placed in series, there is a glow in the dashboard, if this is also broken, the glow system will not work.