Glow Plugs

Hi
I have just changed my glow plugs ( P38 1997 2.5DSE) and starting first time.
Can anybody tell me if there is anything VISIBLE on the old glow plugs which would tell me they are duff or do they just get tired ?

Stick a battery across them and mind your fingures ! They should glow red nice and quick.

rewmer said:

Stick a battery across them and mind your fingures ! They should glow red nice and quick.

Click to expand...

Seems so obvious when somebody tella ya' !

Testing glow plugs – the right way!
Step 1: The current input is tested at the main electrical connection to the glow plug using a ammeter clamp. If there are four glow plugs in the engine and each one requires 5 amperes, for example, the total current input has to be 20 amperes. If the measurement indicates a lower value, at least one of the glow plugs is defective. The current input varies from glow plug to glow plug. The data for all NGK glow plugs can be found at www.ngk.de/pro.

Step 2: If one glow plug is defective, we recommend replacing the entire set. If only one defective glow plug is replaced, each glow plug has to be tested separately. The resistance between the terminal nut and the metal housing is measured using an instrument that can indicate low test voltages.




Proceed as follows:

Remove glow plug
Clean threads of all rust, dirt, oil or paint
Apply electrodes of the measuring device to the glow plug
If the resistance value is around ∞ Ω, the glow plug is defective.
If the resistance value is below 5 Ω, the glow plug is okay.

[nomedia="http://www.youtube.com/watch?v=LB3sVD_wD7Y"]YouTube - Glow plug test[/nomedia]

The Mad Hat Man said:

Testing glow plugs – the right way!
Step 1: The current input is tested at the main electrical connection to the glow plug using a ammeter clamp. If there are four glow plugs in the engine and each one requires 5 amperes, for example, the total current input has to be 20 amperes. If the measurement indicates a lower value, at least one of the glow plugs is defective. The current input varies from glow plug to glow plug. The data for all NGK glow plugs can be found at www.ngk.de/pro.

Step 2: If one glow plug is defective, we recommend replacing the entire set. If only one defective glow plug is replaced, each glow plug has to be tested separately. The resistance between the terminal nut and the metal housing is measured using an instrument that can indicate low test voltages.

Proceed as follows:

Remove glow plug
Clean threads of all rust, dirt, oil or paint
Apply electrodes of the measuring device to the glow plug
If the resistance value is around ∞ Ω, the glow plug is defective.
If the resistance value is below 5 Ω, the glow plug is okay.

Click to expand...

Thank you TMHM : my education is improved every day on LZ.

TAKdriver said:

Thank you TMHM : my education is improved every day on LZ.

Click to expand...

But remember you cannot test individual plugs unless they are disconnected from bus wire.