Glow Plug Warming Times

[sanjsanj]

I've only had the galaxy for a week now....it my second diesel (first one was a J reg so i can't rele compare my problem to that..)

 

 

Urm, when i turn the ignition to the last position before the starter motor turns, all the dashboard lights (abs, airbag, fuel, handbrake "on" lights) switch on- which is normal...

the glow plug warning lamp also switches on but it goes out pretty quickly i.e around 1-2 seconds.

 

Is this normal? because if you read this:

http://www.boschautoparts.co.uk/pcGlow1.asp?c=2&d=1

you'll notice that they reach around 850 degrees C....surely it cant heat up that quick unless something's rong with it?

 

mk1 t reg gal, Ghia Auto, TD

[NikpV]

the glow plug warning lamp also switches on but it goes out pretty quickly i.e around 1-2 seconds

 

its certainly like that on my MKII under normal conditions - it will stay on longer in very chilly conditions, I used to wonder if it only felt that it stayed on longer when sitting in an icebox waiting but it definitely gets to around 5 sec on occasions

[Guest 3.5bullet]

i've read somewhere that on certain models the glow plugs start to heat up when you unlock the door , so the waiting time for them to extinguish is shortened! so you dont have to sit around waiting to start the engine on the cold mornings so much:D

[Topbloke]

i've read somewhere that on certain models the glow plugs start to heat up when you unlock the door , so the waiting time for them to extinguish is shortened! so you dont have to sit around waiting to start the engine on the cold mornings so much:D

usually the light on is only an indication of a minimum time that you should wait, on modern diesels there is a sensor that takes a reading of the engine temp and sends a signal to the glow relay, when the engine is warm does the glow plug light come on at all ! if not then this would suggest that a sensor is fitted and is working correctly

[sanjsanj]

i've read somewhere that on certain models the glow plugs start to heat up when you unlock the door , so the waiting time for them to extinguish is shortened! so you dont have to sit around waiting to start the engine on the cold mornings so much:D

 

hmm... i can believe this for my friends S-class 2003(cdi): its got that keyless entry/start thingy, so all he does is press the break and little switch on the gear knob and it starts straight away- just like starting a petrol.

But his car's newer than my T reg...i dont think this kinda technology wud have been used for fords around then:

 

J clarkson:"if u wanna know whats gunna be standard on your ford 10 years down the line, then this is the car to look at- the merc s-class"

According to him, it should be on fords in around 2013!

 

Anyone have an MK1? I would really like to compare the glow plug times to an mk1 for reasurance...I think the MK2 diesel engines aren't the same, Nikpv thanks anyway!

[Guest 3.5bullet]

usually the light on is only an indication of a minimum time that you should wait, on modern diesels there is a sensor that takes a reading of the engine temp and sends a signal to the glow relay, when the engine is warm does the glow plug light come on at all ! if not then this would suggest that a sensor is fitted and is working correctly

 

taken from a technical article

 

The glow plugs are controlled by the PCM and their operation depends on engine coolant temperature and engine speed. At temperatures below 9

[NikpV]

when the engine is warm does the glow plug light come on at all

 

It always comes on no matter how high the engine temperature (at least on ours) presumably as a minimun test showing that the bulb works

[sanjsanj]

usually the light on is only an indication of a minimum time that you should wait, on modern diesels there is a sensor that takes a reading of the engine temp and sends a signal to the glow relay, when the engine is warm does the glow plug light come on at all ! if not then this would suggest that a sensor is fitted and is working correctly

 

taken from a technical article

 

The glow plugs are controlled by the PCM and their operation depends on engine coolant temperature and engine speed. At temperatures below 9

[Guest 3.5bullet]

 

Can you please give me the links to those articles? Thanks.

 

 

 

 

the articles in question are to the right of me on the shelf in paper form :16:

[NikpV]

Also, to check if the glow plugs are actually alright, wouldn't it be a good idea to enter via the passengers door and THEN see how long they stay on for?

 

but the passenger door courtesy light may set them off too :38:

 

now how about we enter through any door, deadlock the doors to disarm the volume alarm (2 presses on the remote) suspend a hammock between the A and D pillars kip the night in the car and then in the morning reach down insert the key and then time how long the light stays on. And if it was a mild night we repeat the experiment until we freeze our n*ts off

 

:16: :23: :23: :38:

[sanjsanj]

Also, to check if the glow plugs are actually alright, wouldn't it be a good idea to enter via the passengers door and THEN see how long they stay on for?

 

but the passenger door courtesy light may set them off too :38:

 

now how about we enter through any door, deadlock the doors to disarm the volume alarm (2 presses on the remote) suspend a hammock between the A and D pillars kip the night in the car and then in the morning reach down insert the key and then time how long the light stays on. And if it was a mild night we repeat the experiment until we freeze our n*ts off

 

:16: :23: :23: :38:

but is says drivers door courtesy light switch

[NikpV]

so go and try - tell us the results

[sanjsanj]

 

Can you please give me the links to those articles? Thanks.

 

 

 

 

the articles in question are to the right of me on the shelf in paper form :16:

 

OH! I thought that you wouldn't have gone through ALL that trouble for me! because it was quite lengthy, i presumed you copy and pasted it!

any chance you have a scanner?

 

so go and try - tell us the results

 

well the engine hot at the moment...wouldnt be a fair test! will do soon.

if you think about it, if it would heat up on any door opening, you could very well run the battery flat!

[NikpV]

Back to your original question ... sort of, a back of an envelope calculation to show the likely heating times

 

mass of glowplug tip -10g

specific heat capacity - 0.5J/g/C

temp increase - 800C

 

so each glowplug would need 4000J supplied by the 12V, so if it really heated up in 2sec each would need a current of 166A if connected in parallel a current of 666A. um but high - starter usually takes the greatest current 150A ish (maybe 200A)

 

More realistic to assume 20s - would give a current of 66A - same as heated front screen - much more reasonable.

 

 

Yes I know it takes no account of heat losses, electrical losses in wires but it gives a minimum current - oh and it doesn't matter if you do the calculation in series either - try it

 

 

well the engine hot at the moment...wouldnt be a fair test! will do soon.

if you think about it, if it would heat up on any door opening, you could very well run the battery flat!

 

 

I've just tried it passenger door - glowplug light goes out after 2sec give or take - slightly shorter I would think

[Guest 3.5bullet]

you could connect a test lamp or meter to the glow plugs, then open the drivers door and see what happens? then do the same with the passenger door? either the lamp will illuminate? or you will get a reading across the meter? depending on which method of testing you try?

[NikpV]

you could connect a test lamp or meter to the glow plugs, then open the drivers door and see what happens? then do the same with the passenger door? either the lamp will illuminate? or you will get a reading acroos the meter? depending on which method of testing you try?

 

 

Hey its 11:40 - I'm not going to try that in the dark just for Mr Sanjsanj :23: :16:

[sanjsanj]

you could connect a test lamp or meter to the glow plugs, then open the drivers door and see what happens? then do the same with the passenger door? either the lamp will illuminate? or you will get a reading acroos the meter? depending on which method of testing you try?

 

 

Hey its 11:40 - I'm not going to try that in the dark just for Mr Sanjsanj :23: :16:

 

Watch it mister. you may have not noticed where I live. I suggest you take a look and then, think before you speak! otherwise, i'll force you out!! :38:

 

And how are you gunna connect anything to the same circuit as the glow plugs? dont you have an MK2? and by flatten the battery, i meant that if you were moving, say, each seat out of the car and you've parked far from home (BLIMIN PARKING!!) you've just heated it up 5 times (locking car when taking back seat.)

and then you've gotta open it loads of times to put things IN it...

 

And whats this volume alarm? i thought it was an ultrasonic movement detector!

 

And thats sanjsanj not Sanjsanj!!!!!!!!!!! :23:

[sanjsanj]

NikpV: your status has been "posting in glow plug warming times" for quite some time now......

dont make me come up there, drag you out of bed, make you do a glow plug experiment and then ask you for a reply to my previous post!!!

[NikpV]

Watch it mister. you may have not noticed where I live. I suggest you take a look and then, think before you speak! otherwise, i'll force you out!!

 

 

ooooh I'm trembling :38:

 

I've just tried it passenger door - glowplug light goes out after 2sec give or take - slightly shorter I would think

 

Look at the figures - battery has about 180 glowplug heating cycles in her, how many kids did you have to get in, seats out etc did you say. Mind you its 3.5bullet who said the door thing. :16:

 

And whats this volume alarm? i thought it was an ultrasonic movement detector

 

it is - too long to type and I can never remember the write worms :23: :23: :38:

[Ogben Schmutzel]

For what its worth I have read somewhere that in all but the coldest (below 5 C I think) the car will start without waiting for the glowplus to warm up! And to be honest there has been times when i have fogotten even when that is the case and the car has never failed to start firtst time!! (umm except when i filled it up with unleaded once!! :19:

Cheers.

Oggy.

[sanjsanj]

For what its worth I have read somewhere that in all but the coldest (below 5 C I think) the car will start without waiting for the glowplus to warm up! And to be honest there has been times when i have fogotten even when that is the case and the car has never failed to start firtst time!! (umm except when i filled it up with unleaded once!! :19:

Cheers.

Oggy.

 

wow i've realy wanted to know what happens to a wrongly fueled car....what exactly happened?

[Scorpiorefugee]

For what it's worth and if my old wreck of a Gal is anything to go by, these things will start without glow plugs almost immediately at temperatures above 10C and take about 5-10 seconds of cranking at freezing point.

 

I had a fault on mine and it ran for 9 months and 20K miles completely without functioning glow plugs.

 

From a cold start, at current temperatures, they are on for about a second and that's it. No partials or anything else fancy, there's no variable or anything else. At 40-60 amps, I wouldn't think that the electrics would stand much messing about and, short of pulsing the relay rapidly, there is no way of varying the power and I doubt the relay would last very long doing that.

 

I have read a few articles about these things but tests made during and after fixing indicate that it's very simple. They come on for a second or so after switching the ignition on and that's the end of it. I've always assumed that, once fired up, the heat of the explosions is enough to keep the glow plug tips hot.

 

But then again, I'm no expert but always believe that the simple explanation is usually right.

 

Ron.

[NikpV]

For what it's worth and if my old wreck of a Gal is anything to go by, these things will start without glow plugs almost immediately at temperatures above 10C and take about 5-10 seconds of cranking at freezing point.

 

out of interest - what model ??? mkI or mk II

[Masked Marauder]

standard alarm is just repeated horn sound - dead dull :16:

 

It is actually it's own horn that is quieter than the road horn. Indeedee it is so quet that with double glazing you might not even hear it when it sounds.

 

 

I have read a few articles about these things but tests made during and after fixing indicate that it's very simple. They come on for a second or so after switching the ignition on and that's the end of it. I've always assumed that, once fired up, the heat of the explosions is enough to keep the glow plug tips hot.

 

Ron.

 

I have connected one up to a battery to test it and the tip was glowing red in about a second. In addition to that there is no connection to the ecu from the door pins. QED.

[Scorpiorefugee]

Just out of interest MM, did you check the current?