W211 Warning light

[pomm001]

Has anyone come across this :

my 2004 E220 has the following condition, insert key, all warning lights on
a few seconds latter the 'glow plug' light goes off, start engine and proceed.

It now runs through the same sequence, but the 'glow plug' light comes on
again when the engine has started and remains on for about 30 seconds, it then goes off and stays off for the journey.
This does not bring up an error / malfunction message in the speedo display.
Yes i could book it in with the dealer but being self employed, it will cost me half a days pay as well so though would ask the good people of the forum first



many thanks .

 

[Blobcat]

The glow plug waring light comes back on to let you know that one (or more) of your glow plugs have failed. You can either get them all changed or just the faulty one(s). I would recommend getting the faulty one changed soonest.

 

[pomm001]

The glow plug waring light comes back on to let you know that one (or more) of your glow plugs have failed. You can either get them all changed or just the faulty one(s). I would recommend getting the faulty one changed soonest.

Thanks for the response, welcome news

where else can you get such fantastic advice on a wet sunday afternoon !

Are they reasonably accessable ? and check with a meter for continuity ?

many thanks

 

[pomm001]

The glow plug waring light comes back on to let you know that one (or more) of your glow plugs have failed. You can either get them all changed or just the faulty one(s). I would recommend getting the faulty one changed soonest.

My local factor only had two glow plugs in stock
i checked for continuity and found #4 cylinder down, removed carefully and replaced with new one.
The old onit looked good so i checked it again and found that it now had conituity ?
Ran the car and light went out.... next time i started it stayed on again
So checked them all again, all had continuity, this time i paid a litte more notice on the values... from memory the limit is somewhere near 1.5 , this one had 5.6, so replaced it with a new one, again with unit out i checked it again only to find now measured 1.5
Ran the engines and light comes back on again ....
Any suggestions why when i remove the plugs and check them i get a different reading ?
what should i do next , logic tells me to replace the two remaing plugs with new ones and see what happens ...

Is there a re-set procedure to clear this warning lamp ?

any similar experiences

many thanks

 

[pomm001]

following on :

I now have replaced all 4 glow plugs and the warning lamp still comes back on after a 'cold' start.

I guess is should now check that that each supply lead gets current from the relay
Is the relay in the top left hand side of the under bonnet area ?
If one of the feeds is 'out' does this mean the internal fuse may have gone ?
if so does anyone know if the unit can be opened and repaired

any suggestions please

thanks

 

[Ellsy Tanners]

I would try this several times, it will take a while for the glow plug unit to re measure all the resistance values and stop putting the light back on. trust me give it a few tries, as a normal start up procedure and you may find it will be ok after a while before you pannic and change something eles.

 

[Ellsy Tanners]

The glow plug unit is located on the passenger side front wing. its a small box 10cm square and will have a part number something like A025 545 28 32.
Pull off the large multi conection havind 4 wires and two blanked of caverties. Test the wire resistance to a good earth. the values should be the same for all 4 glow plugs, this will tell you if one is at fault. the number on the plug refers to the number cylinder glow plug, if you still have a differrent valve for a plug you can now test the indervidual leads.

 

[pomm001]

I would try this several times, it will take a while for the glow plug unit to re measure all the resistance values and stop putting the light back on. trust me give it a few tries, as a normal start up procedure and you may find it will be ok after a while before you pannic and change something eles.

Thanks for the advise
i found the unit as you said on the inner wing ,all resistances seem to be the same as it has all new plugs.
Strangely enough the light only stays on after the first 'cold' start of the day in the morning
on starting to leave work after standing all day the light does not come on , Maybe its not cold enogh to use the glow plugs ?
Will give it a few more days to see if it settles down, must admit it is ticking me off a bit now
next step is to check current/voltage out of relay on a 'cold' start to see it giving power out to all 4 plugs
anyone know if these relays have the 'fuseable' link inside ? anyone had one down to its knickers ?

many thanks

 

[television]

Do bare in mind that faults from a cold start do come from a tired battery. the term for this is caused by under voltage at the start.

What happens is that if the battery has a problem like one cell going partial short circuit, the car will start fine but the standing voltage will be down to around 11.75 volts. This is easily checked with a voltmeter first thing before starting.

The reason why its OK on the second start is that the battery has recovered enough not to record low voltage. This affects cars in different ways, and some may and do show a different error.

These days with cars that are active and never switch off, 4 years is a fairly good life.

 

[pomm001]

The glow plug unit is located on the passenger side front wing. its a small box 10cm square and will have a part number something like A025 545 28 32.
Pull off the large multi conection havind 4 wires and two blanked of caverties. Test the wire resistance to a good earth. the values should be the same for all 4 glow plugs, this will tell you if one is at fault. the number on the plug refers to the number cylinder glow plug, if you still have a differrent valve for a plug you can now test the indervidual leads.

Update

after ingoring the warning lamp for a while i had another look
checked the voltage out of the glow plug relay and found one dead terminal.
I removed the unit and unpicked the sealer around the edge and opened the plastic cover.
The terminals comer off of a large copper 'buzz bar' at the PCB and have a 'thin leg' section along its length, this had blown
after a quick repair with a suitable piece of copper wire soldered across the gap normal service has been resumed, no more warning lamp
But what does confuse me is that there is still contanuity from the buzz bar to the terminal but it didnt provide a voltage when switched

any ideas

thanks