Glowplug advise needed...

[Locky]

Hi all... I need a bit of advice. I've been reading posts about how the glowplugs on a 220 cdi w210 chassis can be troublesome. I thought I would replace them anyway as the car has done 130,000 miles on the originals. I replaced three of them with absolutely no problems at all. I thought it was going too well. The plug at the rear makes a creaking noise when I try to undo it. I indone it approx 1/8 of a turn and decided to leave it for fear of it breaking off. I sprayed wd40 down in the bores in the morning and changed the plugs in the afternoon. Not sure if this plug needs more soaking or is just carboned up and not worth worrying about until it stops working. It works fine at the moment. It's just annoying me knowing I have one old plug in there. A friend suggested putting a little diesel down the plug bore as this is what most releasing agents are. What do you all think?

I'm about to change the drive belt tomorrow and worry that I might also have the sized alternator clutch problem. Has anyone changed this without removing the alternator?

 

[SSBB]

Hi,
the creaking noise does'nt always mean it's going to snap, however IMO it's certainly corrosion thats making it 'tight'. You can try seeping freeing fluid down the thread. Also try doing it back up every time you undo it, ie half a turn undone, quarter turn done up and repeat. Its also a good idea to heat the threads with a blowtorch, this will expand the metals and free off any corrosion. At the same time apply the other methods above. Hopefully it will come undone, however there is an art to this and any good mechanic will confirm it when I say you can 'feel' when its going to snap.
Unfortunately if its that badly corroded then your fighting a losing battle, the glow plug is weaker than the cylinder head and will give way first.

hope this helps
Shane

 

[Locky]

None of the others were corroded at all. I think I might have another go at it tomorrow. Is it best to do it with a hot engine? I did the other 3 cold

 

[Jukie]

None of the others were corroded at all. I think I might have another go at it tomorrow. Is it best to do it with a hot engine? I did the other 3 cold

Definitely a hot engine - as hot as you can safely work on it so that the head expands slightly. You did well to get 3 out when cold. Make sure you don't break a plug. The head will have to come off if you do and that will be expensive.

Trust me - I know!

 

[Locky]

jukie, how much force did you putting on the plug before it broke? was it quite a lot? or moderate. I tried snapping one of the old plugs in a vice to get a feel for it and it seemed to take a lot to break it.

 

[Parrot of Doom]

I was too scared to do this job on mine

I'd buy some freezing spray like this:

http://www.busters-accessories.co.uk/proddetail.asp?prod=LTFR

And work very slowly on that plug. Spray it, turn. Leave it for a bit, then repeat, and again and again. Turning it the other way can't hurt either. Its going to take time, but not as much time as it would take if the plug snaps

 

[tamrsoft]

Seized Alternator pulley clutch

I have to do mine since it is seized also, I have been told it can be done in situ by inserting a hex key of the right size into the front end of the shaft (there is a hex recess to accept it). The key passes through the centre of the splined socket which is used to remove the pulley.

 

[Locky]

Ok well it snapped. The threaded part came all the way to the top then pink~* it's snapped off... I have all of the threaded part out just the pencil section is stuck in there.... any ideas anyone? I was going to drill it and thread a bolt into it, but if it didn't come out by uncrewing it I don't think it will come out with a direct pull...
I tried starting the car up to see if it would fire the broken piece out but it didn't

 

[Parrot of Doom]

Try what you just said, only use the spray I linked to above to ease it out.

Careful about firing it out, I believe they fly out with serious force!

 

[Dieselman]

There is probably still some of the thread left.
Try using an ezi out down the inside of the plug. If all else fails use a drill guide of some sort and drill the plug shaft out, slightly undersize, then run a tap down the thread.
Make sure you pipck up the start of the thread so as to cut the old plug without damaging the thread.
iirc the thread is 12 x 1.25mm, but check this.

Once the thread is cut the plug shaft should be retrevable.

 

[Locky]

I was going to thread and tap the plug stem. Wind a piece of studding into it. Then slide a weight up the studding to a nut on the end. Like a slide hammer. Do you think the freezing spray will cause the glow plug stem to break if I do this? It must only be the carbon holding it in there. I suppose if it does I will have to rely on drilling. I'll just vacume out the cylinder bore through the injector hole. I have a bore scope I can use to see if it is clean.

 

[Locky]

hi dieselman.... I actually have the hexnut, the threaded part and about 10mm of the shaft out. It's just the rest of the shaft that is jammed in there. It should be a simple case of pulling it out, but I think carbon has built up around it.

 

[tamrsoft]

Locky,

Got the follwoing article from a USA froum, thought it might help in your situation. Keep us posted on your procedure and results, it's a common problem that many of us will face.

 

[Locky]

Thanks tamrsoft. It was a good read. It's actually quite reassuring seeing other people recover from the situation.
I was speaking to a local engine tuner, and he was telling me you can remove a core from the pre-combustion chamber to get at the tip of the plug. Maybe it will help to recover the tip if I have to drill. Does anyone know if this is true? I believe you need a special splined socket to remove it. http://www.technictool.com/prechamber-tools.htm
I'm going to have a go at it this sunday. I'll take some pics. I've been thinking about it and I'm going to try silver soldering a rod onto the end of the conducter that runs down the center of the plug as I have about 8mm of it sticking out. Then use a slide hammer on it. I tried pulling on the conductor on one of the old plugs and it seems pretty strong.

 

[silverarrow]

take the head off honest way to do it
did you use the special "grease " on the new plugs
not many garages know about this makes the new plugs easy to remove
NB it is not copper ease

 

[Dieselman]

You won't be able to unscrew the pre-chamber because your engine doesn't have one.

 

[Locky]

ok well here's the end result. (images are clickable)
I bought some high tensile studding from my local nut and bolt merchant.

In this pic you can see the conductor sticking up from the plug


So I drilled a hole up the end of my piece of studding and silver soldered it to the conductor. This was a strong weld with an old glowplug I had spare.



But on this plug it just ripped the conductor out.



But this was good in a way as it let me wind a modified tap down the shaft of the glowplug.






I don't actually own a slide hammer so I used a big block of stainless I had lying around.



Some Freeze spray and about 15-20 good pulls on the lump of steel and out it came in one piece. The biceps are aching a bit now.

 

[grober]

Some good pics. Should probably go into the HowTo section together with tamrsoft's word article. If nothing else it serves as a warning glow plug removal is a risky business! A good lesson that when things go wrong IMPROVISE. Well done, probably saved yourself and maybe some forum members a lot of money!

 

[Dieselman]

Well done Locky.
An excellent piece of engineering practice there. It just shows though, you don't need to remove the head to remove a broken glow plug.

If you did this again it would probably take you about an hour all in.

Top job, have a narna.:bannana:

 

[Locky]

Thanks for the comments. I was very glad to see it come out. I'd be happy for it to go in the howto section if it is useful. I can write a more in depth description if required.