Another glow plug query

[Greenthing]

Hello, I`m going to attempt to change the glow plugs on my 1998 w202 c250 turbo diesel. I`ve read up as much as I can from this and other forums but there`s a couple of questions I`d like answered if possible please.

On one thread it says I need a special tool `11mm socket IIRC`, but the plugs I`ve bought are 12mm. Is this because I`ve bought a cheaper set of plugs and the ones I`m about to remove are probably 11mm? I`ve done much searching but can`t find the special tool or an 11mm glow plug socket anywhere.

Also, if I remove the inlet manifold, do I need a socket anyway or can I get to them with a spanner. If I do need a socket will an ordinary socket work or does it have to be a deep reach?
The reason I ask this is that I have a limited ammount of time do the job and will have to make sure I have the right tools at hand.

 

[a111r]

11 mm ... must be a 'Spinal Tap special'

No special tool, just a deep 3/8" drive socket, not a spanner (either 10 or 12 mm, I can't remember).
The IM needs to come off to do all of them.
It's not a job to undertake with limited time, either. Prep. them well, with penetrant, time and heat ... and take it slow on removal.

 

[Greenthing]

11 mm ... must be a 'Spinal Tap special'

No special tool, just a deep 3/8" drive socket, not a spanner (either 10 or 12 mm, I can't remember).
The IM needs to come off to do all of them.
It's not a job to undertake with limited time, either. Prep. them well, with penetrant, time and heat ... and take it slow on removal.

Thanks for clearing that up for me. I`ve also read on an american forum that one way to make it easier is to try and break down the coke deposits/build up, by using additives over a period of time. But do you think it might be possible to break up some of the deposits around the plugs by purging the system, or to put it more planely, filling the fuel filter at least half full with red-x or something similar. I`ve done this on a 1.9d golf engine before and it seemed to get rid of lots of unwanted nastiness.