i have recently bought a 2004 53 plate Vauxhall Astra 1.7 CDTI SXI. Firstly i absolutely love the car, it's so economical and comfortable to drive. It has 74,000 miles on the clock and is in very condition with no marks inside or out. However i had a bit of trouble with it a couple of days ago and have scoured the internet looking for other peoples similar experiences and the reasons behind the problem. I'm a builder so i am very hands on and whilst i'm not a mechanic by any means, i do know a little about how cars run and i have done a few minor bits of work on my previous cars i.e. oil changes, brake discs and pads, replacing exhausts etc usually following the instructions in a Haynes manual. I'm only mentioning my experiences because i want you to get a good idea of my limited knowledge so you can advise me accordingly if you would be so kind. Ok so the car had been running like a dream, starting first time with no problems until about 3 days ago. I had left from work and driven about 5 miles to the post office to pick something up, having collected my post i return to the car (i must have been about 5 minutes). I got in it and as normal turned the key (i cant remember if i saw/waited for the glow plug light to go out). The car turned over with a very healthy and lively sound however it did not start. I tried again but to no avail noticing there was definitely no glow plug light at all when turning the key. I tried every couple of minutes and each time the engine turned over very energetically but still no start and not once did the glow plug light come on. After about 20 minutes i tried it it turned over very well and it sprang into life, there was still no sign of any glow plug light when i first turned the key but it was running THANK GOD!!!! (PLEASE NOTE NOT ONCE HAD ANY ENGINE MANAGEMENT WARNING LIGHTS COME ON) I didn't want to drive it far just in case it conked out so took it straight to a local garage where they ran a diagnostic and found 4 faults of which 2 he said were ERG faults i think. He cleared the cars computer and said if it happens again bring it back then they can find out for sure what the fault is by running another diagnostic. He didn't charge me for the diagnostic and was very helpful. Since that day the car had been starting absolutely fine, and is running beautifully however the glow plug light rarely comes on at all and if it does it is for about half a second. I have searched a lot of other forums and keep hearing about glow plugs/lights don't come on unless it is under a certain temperature. Is this true? It's just every diesel i have ever driven (even my company van which is only a year old) the glow plug light will always come on for at least 2/3 seconds. So if you could clear this up it would be great. Also if you have any idea of why the car wouldn't start the other day could you let me know? I have tried to include as much helpful information as i can to help you with your answers. Thank you for your time.