Mercedes C220 CDI glow plug testing and removal procedure

[birzai]

HI,

Could anybody tell me how I should test and remove glow plugs from C220 CDI '00 engine?
I checked the access is very limited. What kind of tools I should have and where can I get detailed procedure of doing it?
Thanks

 

[Ellsy Tanners]

Hi Birzai,

Wait untill Television comes on and he will be able to send you a how to if you like.

My tips are get the engine to full opertating temp. You will need a deep 10mm socket to remove the glow plugs.

To test, remove the large plug on the the glow plug relay and test the pins to earth. A poor plug will have a very large resistance or open circuit.
The numbers on the plug relate to which glow plug number the wire goes to.

 

[birzai]

Hi,

As I said access to glow plugs is very limited do you want to say I do not have to remove any other items to get better access?
Would you mind to tell me where is located glow plug relay in the engine?
I can not find it. I just want to remind it is CDI engine.

Thanks

 

[Ellsy Tanners]

It should be located on the passenger wing. Is it a 202 or early 203?

You should be able to change the plus without moving to much. If needed be one off the plastic fuel pipe may have to come off and possibly the solid metal pipes, but give it a go with a small socket and just remove whats necessary.

 

[birzai]

It is 202 model.
I tried to follow by glow plugs connector leads to find relay but I could not.

 

[Ellsy Tanners]

I am sure it is under the washer bottle on the 202

 

[brianbrian]

Don't forget to disconnect Battery.

 

[birzai]

I think glow plug control unit is in the ECU box. I was opened this box and there many wires. I tried to disconnect one plug with 4 leads and then checked if glow plug indicator works on dash. It was not.
Then I tried to test it for continuity by multimeter, but the multimeter showed not any results. I connect negative to engine part and positive to plug holes and set multimeter to ohm. The multimeter was reading 1. ohm and there nothing changed when I tried connect leads to plug holes.
Would you mind to explain what it is? Did I anything wrong?
I noticed that there is one black box under windows washer tank, do you are100% sure glow plug relay is over there?

 

[Ellsy Tanners]

I think glow plug control unit is in the ECU box. I was opened this box and there many wires. I tried to disconnect one plug with 4 leads and then checked if glow plug indicator works on dash. It was not.
Then I tried to test it for continuity by multimeter, but the multimeter showed not any results. I connect negative to engine part and positive to plug holes and set multimeter to ohm. The multimeter was reading 1. ohm and there nothing changed when I tried connect leads to plug holes.
Would you mind to explain what it is? Did I anything wrong?
I noticed that there is one black box under windows washer tank, do you are100% sure glow plug relay is over there?

About 95% its been a while, very easy to lift up and have a look!

 

[birzai]

I found it. I tested all 4 glow plugs for continuity and there were all 0.03ohms. So I think it is ok. I test glow plug relay voltage and it was fine.
I think there is only one problem, bad battery as I can not find another reason why my car fails start at the cold morning and it is fine during the day.

 

[robamb]

Heater Plug removal

My son has a C220 coupe and the glow plug light would stay on. He lives 90 miles away from me so diagnosis was done over the phone. We decided to try a new set of glow plugs which cost £40. I did some research into removing them on tinternet and saw all the nightmare stories, so tried to give myself the best chance and sprayed the plugs the night before with some graphite spray and on the day drove the car to warm it up. I used the reverse action with a torque wrench set to 20NM and they all cracked off easily and came out without any problems and the job was completed in 20 mins and cured the problem.