Glow plugs

Hi

I have had my 90 for about 4 months now. It's always taken about 15-20 secs on the pre-heat to start it. Coming from a 200tdi disco this seemed like a long time to me.

I have read that anywhere between 10-30 secs is the norm.

Thought I'd give them a quick check before the really cold weather comes.

With the multimeter there's only about 0.3 resistance so that is fine.

Decided to take them out and connect them up to 12v supply while in a vice to see how long they took to glow. To fully glow they took about 12 secs.

Is this normal ?

If I replace with new plugs would they only take a few seconds to glow completely and let my start the 90 quicker night mornings ?

Cheers for the advice

i allways check them by removing and testing with jump leads if they dont glow more or less straight away ,replace them , more heat will be needed for 2.5 rather than tdi as they are prone for bore wear meaning lower compression ,they are indirect injected , and injection poressure is 135 bar compared to 280 bar so good glow plugs are needed

Thanks for the reply, mine were taking about 12 secs to glow fully. Looks like new glow plugs are in order.