2.5v at glow plugs on a diesel?

[treeman]

Trying to work out why my 3.0 diesel X5 wont start. All glow plugs show good resistance when checked with ohm-meter so assuming they are fine. With the key in position 2 (normal run position) I only got roughly 2.5v from cap to plug head - does that sound about right?

I'm guessing only get 12v + if actually starting/cranking the engine or if glow plugs in pre-heat phase.

[rb0135]

What Year? More details are needed.

What exactly is it doing in not starting. Is it cranking?

Glow Plugs only operate when the temperature is below 2 degrees celsius and depending if you have a pre or post model, 2.5 volts would be right for a post (2004 greater diesel) as the Glow Plugs are 5 volts. The pre models they are 12volt (I think by memory.. might be the other way around).

Probably better to post on the UK boards as the US guys didn't have the E53 Diesels.