No glow light on C220 CDI W204?

[domwild]

Hi friends,

My manual says the glow light symbol should be near the 200 km/h mark, one Youtube video showed it near the RPM gauge. Anyway, it is not there before during starting.

Any solution to my problem or is it a case of buying a diagnostic tool and connecting it and looking for the error codes?

Thanks.

Regards
domwild

 

[umblecumbuz]

Nice car.

In this cold spell, how easily does the car start?

Buying a good code reader - one that will handle Merc's own codes, not just a cheap generic reader - is now part of routine home maintenance, and obviously a good way to go.

Just seen your almost duplicate thread on the same subject, and found out that you're in Perth, Oz. Not quite so cold!

Best to keep similar queries on one thread for clarity, really.

 

[domwild]

Nice car.
Buying a good code reader - one that will handle Merc's own codes, not just a cheap generic reader - is now part of routine home maintenance, and obviously a good way to go.
Best to keep similar queries on one thread for clarity, really.

Thanks for advice. One Youtube video suggested an i980 diagnostic from iCarsoft, sold by Diagnostic World UK. Would this be a "good" tool for this 2007 (sorry, not 2010) C220 CDI or is there a "better" model for Mercs available? Any suggestions?

 

[umblecumbuz]

That's a good tool, used by many on here.
A better one is the iCarsoft MB2. Clearer, and with more features. Dearer of course.

 

[domwild]

That's a good tool, used by many on here.
A better one is the iCarsoft MB2. Clearer, and with more features. Dearer of course.

Many thanks for that. Have ordered the i980 and the shop asked me for VIN number, etc., I might as well in that email also ask how much the MB2 is and possibly send him more money.

Dr Google found me this excellent glow plug repair link, which just uses a multimeter to check out the glow plug relay to find the dead glow plug, etc. Here is that link:

http://dieselgiant.com/glowplugrepair.htm

Now I have to ask Dr Google where I can find the relay.

 

[domwild]

It gets better, Dr Google found this:

http://forums.mercedesclub.org.uk/i...-the-glow-plug-relay-on-a-w203-220cdi.125600/

This chap found a blown fuse in the relay, which cannot be opened easily, so he drilled it open and repaired with a fuse, which looks a bit too small with 30 Amps. I believe someone calculated two glow plugs at 17A each and two at 12A, so 34 plus 24 = 58!

 

[domwild]

Silly question: Where do I find the preglow relay in a C220?

 

[umblecumbuz]

Layout of C class's varies underbonnet, but probably if you look right as you face the engine from the front, just in front of the battery box and a little lower, and you will see a black boxlike object with heavy wires running into it. That's the johnny.
Nb. Estates have the battery at the rear of the car, but the general info here should lead you to the relay.
Others here have cut theirs open and replaced a fusible link with success.

 

[domwild]

Layout of C class's varies underbonnet, but probably if you look right as you face the engine from the front, just in front of the battery box and a little lower, and you will see a black boxlike object with heavy wires running into it. That's the johnny.
Nb. Estates have the battery at the rear of the car, but the general info here should lead you to the relay.
Others here have cut theirs open and replaced a fusible link with success.

Thanks, umblecumbuz for help. The battery is in the boot, so I will have to look in the engine compartment. There is a possibility it being in front of the driver's side head lamp (?) or near the thermostat.

Yes, the chap who drilled it open and was told to saw it open (easier!) certainly saved himself some money. But one also has to have a look at the glow plug's resistances as a shortened glow plug (zero resistance) would have caused the fusible link in the relay to fail in the first place.

Looks like I should have talked to Dr Google re this model as one chap is listing there five problems with this class. By the looks of it, when I test drove it, I did not noticed the lack of a glow lamp indication, first mistake. Driving it and noticing in our Aussie summer the temperature being in the seventies rather than the correct nineties, the second mistake happened of not noticing a faulty thermostat. WILL I STILL LOVE MY C220 IN THE FUTURE?

What is interesting is that that user had a service done just before the sale by a proper Mercedes shop and with the diagnostics the glow plug problem would have shown up and the low temp. and lack of preglow indication would have shown up during the prescribed test drive. Perhaps this was the reason for the sale? Had I offered him less money, he would have looked for another dummy!

I will have a look at that shop as the mechanic surely wrote all that down in his report, besides, it looks like the first time the air filter was changed was at 120,000 service?!? Looks like as long as the mass air flow is just within speci, no one bothers with compressed air any more.

From reading this forum I must change the thermostat first in order to get the temp up for a possible glow plug repair, as many users have snapped off the pencil-thin plugs trying to get them off. The block has to expand to loosen the plugs in the alu head plus plenty of WD-40 has to be used. All that info came from this great forum!

In addition to an i980 diagnostic or similar, do I have to buy a set of Torx sockets if I will keep on DIY servicing?

Anybody out there with a black belt in C220 CDI WDD204 Mercedes electrickery, who can help me with the location of the relay?

So many questions, so little time!

 

[domwild]

Checked plug #1 by just putting the multimeter onto a good earth and other contact onto the centre electrode after the (obvious) removal of the electrical contact - 0.9 Ohm, perfect.

Found two fuse containers, one in the boot near the battery and another in a plastic box on the driver's side under the bonnet. There are no larger relays visible on the two fuse boards.

On the opposite (passenger) side is a box with a slider, which reveals a positive and large spade lug and lots of Newton Metre descriptions for the torque holding the battery clamps on from large copper cables. But only large-diameter cables are present and I cannot see a relay with a plug and four pins going to four glow plugs.

Although I called the relay's name, there is still no reply.

 

[Yugguy]

Dom don't get hung up by the list of faults on any model. These are all the faults ever noticed on the entire run of that model. if you went purely by the Internet you'd never buy any car.

 

[domwild]

Dom don't get hung up by the list of faults on any model. These are all the faults ever noticed on the entire run of that model. if you went purely by the Internet you'd never buy any car.

Not to worry! Do you have any idea where this relay or glow plug control unit sits?

 

[Brizzle]

Silly question: Where do I find the preglow relay in a C220?

Having had to find mine recently I can tell you that on a 2009MY C220 it is under the left hand side of the engine and you need to remove the under tray to get to it. Removing the under tray takes longer than changing the relay

 

[domwild]

Having had to find mine recently I can tell you that on a 2009MY C220 it is under the left hand side of the engine and you need to remove the under tray to get to it. Removing the under tray takes longer than changing the relay

Thanks Brizzle for help. Great! Have seen one owner drain the coolant by just lifting the LH side of the car to remove the under tray for the changing of the thermostat. Another one simply pumped the coolant out, easier.

Did you buy a new one and install it? If a glow plug has a short to earth it will blow the fusible link in the relay (control unit) and users have simply soldered in a new fuse or attached an external fuse and saved $800?! Did you find a shortened glow plug and changed that first so the new fuse does not get blown again?

 

[domwild]

Thanks Brizzle again for help. Have been told by an expert (ex-has been, squirt-drip under pressure), that it must be the LED in such a case, so I will here in Australia having to do the 5 or so seconds wait before starting as I will not see any light to go out.

But I must still change the thermostat as the temp stays in the 70 degree range rather than going up to 92 as stamped on the thermostat.

 

[steveq]

Hi,

I have a C220 CDI W204 with the OM651 engine. Mine is the facelift version from late 2011 which has a different dashboard to the earlier version.
I thought that the glow plug light on mine was not working but actually it is.

You have to really watch the rev counter as the glow plug coil symbol only lights for 1-2 seconds at most when you switch the key to the second level and can be easily missed (I certainly did).

On my E Class with the same engine the glow plug light stays on for longer (2-3 seconds) so is more noticeable.

 

[domwild]

Thanks steveq for help. I will watch it again. The user manual tells me it is at the tacho and I cannot see it there. The good news is, that a Mercedes dealer tells me it is the LED, hope, hope. With the multimeter I have checked glow plug #1 so far, 0.9 Ohms, which is OK. I will also check the supply to each glow plug by getting someone else to turn the key to the second level for a short time.

If one of the glow plugs has gone to earth (a short) with zero resistance, then a fuse has blown in the relay (fancily named the glow plug control unit!) and that means paying $$$$ or sawing it open and either hanging on a 30A external fuse in lieu or soldering a fuse in somehow as seen on this forum.

 

[John Laidlaw]

Glow plug relays are not that expensive

 

[Brizzle]

Glow plug relays are not that expensive

MB unit for the W204 is close to £200 - I consider that expensive!

 

[John Laidlaw]

MB unit for the W204 is close to £200 - I consider that expensive!

I’m sure MB Grangemouth we’re doing them considerably cheaper earlier in the year ? Maybe a special limited offer..
If you think that’s expensive by the way , try an ABC equipped cars repairs for a year !