preglow warning light

[punitsu]

I have 1999 E220cdi, recently after starting the engine, the preglow light comes on and stays on for a minute or so and then the light goes off. every time I switch on the car this happens. any explanation?

 

[Dieselman]

Umm..

 

[alibally]

now now dieselman, sarcasm will get you no-ware

 

[punitsu]

Thats fine, dieselman suggected glowplug change. my query is;How many glow plugs are there? the engine starts ok. the garage says that if the preglow warning light remains on permanently while driving it needs checking. The preglow light goes off, then I start engine and while the engine is on the light comes back again and then goes off after a minute or so.

 

[Dieselman]

It is a blown glowplug, as suggested before. The light sequence is correct, it will re-illuminate for approximately 1 minute after start if one or more plugs are down.

 

[GeorgeA]

At least 1 of your 4 glowplugs needs replacing. I would do all 4 as its the labour that is the most expensive while the glowplugs themselves are about £13 each

 

[Dieselman]

now now dieselman, sarcasm will get you no-ware

I wasn't being sarcastic, I was pointing the O-p to the answers given for the previous time he asked the same question.

 

[punitsu]

Can I leave it for time being or I should get them changed? The car starts ok.
You think by leaving it a bit longer it could get worse.

 

[Dieselman]

It won't make any difference, they are not really required on a CDi engine other than for very cold weather starting and enhanced emission control during engine warmup.

 

[punitsu]

Thanks, I will check out during the coming winter.
Another problem I have is some time the black smoke while driving/revving. I added the diesel cleaner and it seems to improve it. what is an excessive black smoke for a diesel engine?

 

[Dieselman]

Where are you.? In some parts of the World the diesel fuel still contains a high concentration of sulpher, which causes more smoke.
Other reasons, especially on a CDi, are stuck EGR valve and dribbly injectors or blocked exhaust.

Run a neat dose of injector cleaner then check the EGR valve and exhaust.

 

[punitsu]

I am in the Uk, mentioning injectors, I had leaking injectors sometime ago but all seals are now changed and it is no longer leaking, is injector cleaner same as diesel cleaner? I have only used once as suggested for a full tank of diesel.

 

[Dieselman]

Injector cleaner is the same product as diesel cleaner, which is more likely Diesel Injector cleaner.

For best results either use it regulalrly or take the fuel feed pipes from and back to a bottle of cleaner so it recieves a neat dose.
The smoking will probably be the EGR valve sticking open, assuming this to be heavy smoke when first pulling away.

 

[punitsu]

Sure, I will use the cleaner regularly and see if that improves.

 

[punitsu]

After not bothering about the preglow warning, the alternator was damaged and there were bat/alt warning and over/under voltage warning.ABS/BAS/ESP warning! After replacing all four preglow it is fine now.The garage said that something was remaining on/may be pre glow plug, which damaged the alternator! I hope this info will be hellpful.

 

[230K]

Hi

Sounds strange, was the alternator damaged?? What was done to the alternator to fix it??

230k

 

[bigshineybike]

Hi, I am joining this thread since I have exactly the same preglow symptoms.
Thanks for the notes that the preglow light is a signal that a plug is not working. I have the Mercedes manual and this isnt mentioned at all.
Ill go and check this all out.
Makes me think though.....
Do we think Punitsu s problems are with a 'replace and bill' kind of diagnostic service? he has replaced a lot of black boxes and still has a car thats not quite right.
I always like to know exactly whats wrong before I begin to change things.
Forums like this one are so great!