My W210 glow plug removal nightmare...
 

Gentlemen, fellow scholars. I am about to start pulling my hair out.

I got a '99 e300td with 156k on it.
had to replace the glow plugs on it 'cause the GP & the check engine light came on ( ran the codes, it was for the glow plug failure). I went to my regular mechanic who said he will gladly replace them for me. About 2 hours into the job he called me back and said he's not willing to risk snapping them off so he replaced my intake manifold gasket and put everything together and i had to pay him for 2 hours of well, bull**** labor.

i decided to give it a shot myself and it didnt really go so well...i got #6 out without any effort, it was so easy i practically took it out with my bare hands. #5 was a bit more tedious, but it eventually it came out. #4 snapped off pretty much immediately. #3 wont budge at all. #2 snapped. #1 wont budge either.


since i'm already screwed and getting it machined will cost me about 2500....getting a brand new head will cost me about 3gs...i might as well try to drill them out myself.

so...my biggest fear is stripping the threads on the head, anybody have any tips on how to avoid that? i read a few guides and it seems to be pretty much the same process - drill from the center out, every time using a bigger bit until you practically see the threads from the head showing. But how do i get the leftover material from the GP OUT of the threads in the head without damaging them?


please advise. i think im starting to get gray hairs.

thank you

- nazar

Although I do not have specific experience with your model vehicle,
I have had to clear out threads and remove broken parts.

Typically I begin by purchasing a strong set of EZ-Outs , broken bolt
removers. These work like you describe, drill a small hole down the center and then use this to back out the remaining broken piece.

But when it comes to material that might enter the combustion chamber
I remove the head and do it on the bench. You are assured a complete and thorough job without problems.

Don't know what your skill level is, but this can be done at home.
But none of the solutions will take less than a few days, working a few hours each day on each step.

If you were to drill out as you describe, you will absolutely need a tap for these threads to clear them.
You could try vacuuming out the chambers but I have fears that this will leave behind some debris.

Metal debris inside cylinders is always bad, I realy would not try it.

Curious how such a thing could have happened. Hopefully some others
here have some insight on your particular model .

I'm no mechanic, but I am a mechanical engineer and always tinker with everything I can get my hands on....and usually succeed, but this mercedes is driving me crazy. I live in an apartment complex so taking off the head myself is not an option, my friend was kind enough to let me use his garage for a few days so thats where the car is right now.

i found these two guides on how to remove broken glow plugs

http://www.peachparts.com/Wikka/OM606BrokenGlowPlug


http://sites.google.com/site/alanmcreynolds/howtoremovebrokenglowplugs-mercedesom606

and they're both similar, I'm just worried about stripping the thread on the head....

Hi Nazar,

Read up on the procedures people have written here as you found.

On glow plugs that have snapped on the inside, with the threaded part out of the head, you will have to drill and tap them. Use a section of threaded rod or an all thread bolt and nut screwed into the remains and then tighten the nut against something like a socket to pull it out.

If the glow plug has snapped on the outside, leaving the threaded part in the head, you will probably have to drill it progressively larger until the remains of the threads can be scratched out with a pick. If you ruin the threads, they can be replaced with a heli-coil or a time-sert.

When using a thread replacement, you have to be EXTREMELY careful to drill at the correct angle because the glow plug needs to align properly to seal.

Glow Plug Removal Nightmare
 

As a result of issues with seized glow plugs I now have a new head, and a new mechanic. My long time mechanic decided to "save me some money" by welding together two drill bits to remove a seized / broken glow plug. On his first attempt the drill bit broke and punched the water jacket. This led to a great deal of time, discussion and expense. The final resolution came in my offering to pay for the new head on a pro-rated basis (200k on the car - estimated life of the head 500k so I paid 40% of the parts cost and he paid the labour). All inl, his error still cost me more than $2k and I changed mechanics when he complained about his costs. If I had been asked what I wanted to do (I wasn't), based on previous experience with a Peugot and a GM V8, I would have insisted the head be removed and sent to a machine shop. The cost would have been less and I may have salvaged the relationship with a mechanic I had trusted up to that point. All in all, do not cut corners for the sake a few $$$. These cars are just worth too much to be cheap on such a repair. Just spend the money and get the job done right!

I had one bad GP a few months back. After reading about the possibility of this happening, I just had the dealer replace all of the for $600. They also gave me back the old set of GP's that were in the car.

This model is notorious for the glow plugs breaking off when trying to change them out. The glow plug itself has a long pencil like heating element that has a tendency to get carbon bound. When I changed out my plugs, I used used plenty of PB Blaster, and another product called Freeze Off, and let them sit for a day. I also read up on the breaking point of the plugs which is in the range of 40-45 N/M, and used a torque wrench to insure I stayed within that range. I would end up getting about a 1/4 turn on the plug in each direction, and it was a matter of going back and forth with the wrench. If the plug bound up, more PB blaster and Freeze Off would help get it moving again. It was one of the most nerve racking jobs I have ever done, as the plugs have a tendency to squeak when moved. Some posters advise warming up the engine prior to making the attempt to remove the plugs.

Of course ream out or other wise clean the Glow Plug Holes after the Plugs are out.

When the Glow Plugs go back in the head use a Neverseeze type compound on the threads or Beru Glow Plug Grease
http://www.peachparts.com/shopforum/diesel-discussion/221211-beru-glow-plug-assembly-grease.html

I do not believe anyone makes this but what is needed is a Pilot Drill with the Pilot end the same size as the drilled passage that goes through the center of the Glow Plug Body and has an outside diameter that is smaller than the inside diameter of the threads for the Glow Plugs in the Cylinder Head.

The Pilot on the Drill Bit would keep it centered and you only need to drill a little past where the Glow Plug Threads would be.

After that you could follow the Wikki or the DIY to finish removing them.

Below is a pic of one type of Pilot Drill. There is also a type where the Pilot end is smooth so it does not cutting but the end guides it through an existing hole.

I feel your pain - I've been there.

See http://www.peachparts.com/shopforum/diesel-discussion/109101-e300td-glow-plug-stuck-broken.html?highlight=broken+glow+plug

http://www.peachparts.com/shopforum/diesel-discussion/293382-e300d-glow-plugs-wow-easy.html?highlight=glow+plug

lucky you
 

lucky for you you've got a 210 606. There is a tool system the dealer has for removing broken gps from the 210. There is no such tool for the 124 606. Someone posted the video here and it was amazing. Probably still takes a few hours with the tool. That's how I would do it.

Doing this job now
 

I have almost an identical situation. Two glow plugs (cylinders #1 and #2)came out easily on my '99 OM606.962 turbodiesel engine. Three others were sheared off and the sixth was almost all of the way out.
At 260k miles I reasoned that it made sense to remove the head and get the glow plugs removed by a shop with the capability to do that as well as a valve job (guides, seals, grind valves/seats). The shop ended up doing electrical discharge machining to remove all glow plug remains and leave my original threads intact in the aluminum head. Then they "hot tanked" the head and all carbon was removed. It looks like a new head inside and out.
Everything goes back together this weekend I hope! As part of this "opportunity", I also changed all of the hard plastic fuel lines (6), timing chain and guide + tensioner and had my fuel injectors rebuilt with new nozzles and calibrated. Also detailed the engine bay and replaced a power steering hose that was leaking.
The exhaust manifold was sandblasted and I applied Calyx manifold dressing. The 12 year old manifold now looks better than it did on the day I took delivery of the car when it was new.
If anyone wants pictures of anything please let me know before I put this all back together.
Ken

One more vote for pulling the head since at least one plug is already broken. We had three seize in our '98, broke two trying to rock them back and forth with PB Blaster and a torque wrench to limit the loading..I'm too impatient, I'm sure. Then tried drilling two and ended up off center as it's really hard to get the angle right for each plug with a hand held drill and the head is of course soft aluminum. Finally surrendered, pulled the head and a very good local machine shop did a complete valve job and repaired the mess I made of two of the GP holes. (He found threaded inserts - not helicoil type but rather aluminum plugs with threads on the outside and threaded hole for the glow plug on the inside - and used those to make the repair.) Car had 225,000 on it anyway and ran noticeably better after the "as new" head was installed. In our case we found that the binding was in the threaded portion of the plug - no noticeable carbon build up on the tips or on the plug barrels past the sealing bevel. The whole thing ended up costing about $1000.00 total for machine shop work plus a top end gasket and seal set. If this ever happens again - perhaps on the '99 - I'll be soaking them for a week in PB Blaster, using the torque wrench to work them back and forth and settling for 1/4 turn per day if that's what it takes! If one breaks the head comes off. ...or mine does... :)

Ditto on the easy out attempt first, it saved me on a late night in someone elses garage trying to change the GP's on my Jetta TDI. Ran to town and get an easy out and voila it was out. Even though it had anti-seize on it something was wrong, it was either in funny or something was odd about that plug. In reality they had been changed not long before, but it was throwing a CEL so they all got changed.

This happened to my friends car a couple of years ago, he sent the head out to Metric Motors and they removed the plugs, and checked everything over. They also replaced all the valve steam seals and I think all the intake valves were found to be out of spec and replaced. Since it had 200k miles on it he told them to go through it and just replace what was needed. I forget what he paid but it worked quite well the car runs better than ever.