TDCi ignition question

Trojan · 24 Jan 2006 at 18:12

Just a quick question, my Dad recently bought a Mk3 Mondeo TDCi. He's been looking the the handbook and has come across a section regarding the ignition. It states that after he has put the key in the ignition, a "coil" light should appear on the dash. After 3 seconds this should disappear and then it is safe to turn the key and start the engine. Does this sound correct?

If so, why? What damage, if any, will be caused by him just turning the key straight away without waiting for the coil light to disappear?

Scottland · 24 Jan 2006 at 18:18

Sounds like the light for the heater plugs. If he turned the engine over before the light goes off, it might cough a little before it starts (or it might not start at all). But on most modern deisel cars the light goes off very quickly, much quicker than 3 seconds. They probably state 3 seconds, because it can be anything upto 3 seconds.

Hate · 24 Jan 2006 at 18:20

yeah that sounds right for diesels

you have to let the glowplugs warm up to get a nice clean start

blueboy2001 · 24 Jan 2006 at 19:42

The glow plug light on the TDCi's does come on for 3 seconds, but its because it also doubles as the engine management light. The 3 second is whilst the engine checks all its sensors - if there is a problem the light will start flashing.

If its above freezing a TDCi should have no trouble starting on the first turn of the key. I've owned 2 and driven loads of them and never waited for the light to go out.

Fusion · 24 Jan 2006 at 19:57

On the 1.8 TDCi Focus 115ps, the glow plug light literally flashes on for no more than half a second on starting. You can crank it straight up.

Iceman · 24 Jan 2006 at 20:01

Dont really need the glow plugs they are there for emissions
Yeh as said it doubles up as you mil light

Dogbreath · 24 Jan 2006 at 20:40

Iceman said:
Dont really need the glow plugs they are there for emissions
Yeh as said it doubles up as you mil light

They are there on most diesel primarily to help start the engine. If you've ever had to start an old diesel in winter with knackered glow plug you would know how reluctant they can be to start.

NickXX · 24 Jan 2006 at 20:57

Yeah, I have a new golf and you can start straight away (glow plug light turns off after a second anyway). As the above posts suggest, it's really for when the car is knocking on a bit - they will particularly help on cold mornings.

Iceman · 24 Jan 2006 at 21:02

Dogbreath said:
They are there on most diesel primarily to help start the engine. If you've ever had to start an old diesel in winter with knackered glow plug you would know how reluctant they can be to start.

Yeh i know the old 1.8 diesels (fords) are a bitch used to get them in every other week for hard to start
Mainly due to glow plugs

Trojan · 25 Jan 2006 at 07:54

So, in a nutshell, there's going to be no issues turning the engine on straight away, although if it's really cold out it's best to leave it a second or so to let the plugs warm up?

kaiowas · 25 Jan 2006 at 09:23

Trojan said:
So, in a nutshell, there's going to be no issues turning the engine on straight away, although if it's really cold out it's best to leave it a second or so to let the plugs warm up?

Best thing is to just get into the habit of "Get in. Key in. Ignition On. Belt up. Start Car." The couple of seconds you spend putting your seatbelt on will be long enough for the glowplugs to warm up and you don't have to make a conscious effort to wait for the light to go out.

blueboy2001 · 25 Jan 2006 at 12:09

Trojan said:
So, in a nutshell, there's going to be no issues turning the engine on straight away, although if it's really cold out it's best to leave it a second or so to let the plugs warm up?

Spot on.

minidan · 25 Jan 2006 at 19:51

Dogbreath said:
They are there on most diesel primarily to help start the engine. If you've ever had to start an old diesel in winter with knackered glow plug you would know how reluctant they can be to start.

i found this out the hard way lol, 2 glow plugs gave up on my nova and it just dident want to know even after about 10 mins of turning over. just white smoke. sorted with 2 new plugs tho.

-boring stuff i know-
indirect injection diesels are much harder to start when cold (like my nova) and rely on glowplugs. direct injection engines dont rely on them so much but they do make it easyer when its colder.
direct injection is much louder and less eficiant i am told but makes more power and as stated start easyer.

sorry, i just love diesels and wanted to share that lol.

Dan - bored again.

austinpowers · 25 Jan 2006 at 19:56

Other way round, DI is more effient as the fuel is squirted directly into the combustion chamber instead of into a swirl chamber on IDI.

I need to wait for the light to go out on my Astra on these cold mornings ( 2 secs)

DI's are getting quieter with CR and the like, my Astra is quieter than the pug 1.9dt's.