glow plug warning light not coming on

[davecantshoot]

Hi guys,

So i've noticed that the glow plug warning light does not illuminate, even briefly when first turning the key ready to crank. I've gone into the test mode and all the lights illuminate ok there. The engine does start up fine, sometimes there is the odd rattle when it first starts but nothing untoward. I'm just wary as i used to have an old diesel which was giving me no end of trouble towards the end of its life, mainly with the glow plug relay. 

Current car is focus estate 1.5l 2015 model 

[isetta]

How long have you had it? Has it changed? I think it is not showing you the light as it’s not cold enough weather to need u to wait for glow plugs

[IllogicalCpt]

How long have you had it? Has it changed? I think it is not showing you the light as it’s not cold enough weather to need u to wait for glow plugs

Agreed, I have a 1.6TDCi and all through the colder weather the plug light have come on, since spring arrived they don't come on anymore but the car is absolutely fine, I remember being told that you shouldn't really see the glow plug light unless it's cold

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[davecantshoot]

only had it since aug 2017. 28k on clock. It has been showing up until last week but yeah, it has got warmer. Suppose im just wary after my last issues i had with an older c-max. thanks.

[Simon_K]

I think I read somewhere that the glow plugs always operate, light on or not. The light these days is more a cold start warning than a glow plug indicator. 

As above, mine only came on twice I think during the “winter”, but started every time just as easy. 

[isetta]

my understanding is as per Simon_k.  glowplug light means wait for the glowplugs to get up to temperature. Light not coming on does not mean glowplugs are not on, it just means you don't have to wait for them to get up to temparture as there is no cold weather impeding them reaching temperature straight away. 

[TomsFocus]

The light is purely timed and has no relation to the plugs being on or off.  The plugs are used on all starts and during warm up for emissions reduction, and again during DPF regenerating so the light is not linked directly to the plugs on modern cars as it would confuse people.

It's like 0.5secs for 5c ambient, 1sec for 0c for example.

You won't see it at all during the day in the current warm weather, perfectly normal.

 

[Royfoster85]

I Haave this also, i understand it only comes on when its cold.

my question is should it not show when you turn the key to position 1 to test dash lights?

Many thanks

Roy