Snapped off GP, I think. W210
 

I have read all the broken glow plug threads I can find but I don't remember seeing this situation. I was removing #5 after easily replacing #4. 5 was taking a lot more pressure to loosen. I had used plenty of PB Blaster and I was working on a hot engine. Finally enough pressure was applied and I heard a snap and it appeared to come loose. I began backing it out, there was still significant resistance but the ratchet could be turned with one hand. I kept going and going but the plug was not backing out. Still resistance like it is, but it is not coming out. At that point I stopped and decided before I screw anything else up I would come here for advice on my next move. Is it snapped off and is this the normal failure mode?

I know from the other threads there are methods to drill/tap/etc and get the broken off plug out. But this is still one whole plug. Apparently it is separated above the threads as it won't back out. Where do I go from here?

PS: Pulling the head is not an option.

I've changed glow plugs twice on a w210 and haven't broken one yet. But I have had glow plugs make a fairly loud "poping" noise as they break free from the carbon buildup and/or the thread connection with the head. So if your plug is still intact, the threads are loose from the head, and its turning, my guess is that the plug isn't broken but its the carbon buildup that is holding it in. I would continue to spray penetrating oil, keep turning it, and gently attempt to pull it out. I prefer to use penetrating oil spray at this point rather than the PB Blaster because what you are really trying to do is to soften up and flush out some of the carbon build up around the plug so it can slide out.

David Roseman
Long Beach, Ca

Presuming it is not broken
 

Blast the heck out of hit and start screwing back in and out and take it pretty much all the way back in, blasting all the way. Hopefully this will migrate the PB further in and ease your fears of breaking it. And yes, hopefully David is correct and it is just the carbon buildup.

Thanks for the quick reply.

After closer inspection, unfortunately I have indeed broken it off. The attached pic shows where it is broken. Apparently the wiring/element is turning within the plug and causing the resistance to turning. I guess now I just follow the other threads unless someone else has a better suggestion:mad:

Can you compare it to the others to see if you have made it come out at all or not? It is possible to break them so the hex portion just spins free and does not unscrew from the hole...if that is the case then you are sunk.

If, on the other hand you have unscrewed it to the point where all that is holding it in is carbon then you ought to be able to see all or at least most of the threads outside the hole and you can just pull the plug out using vice grips or something like that.

Nevermind my prior post...you are indeed sunk.

Some have had luck drilling them out, some have had to resort to having the head pulled. Either way you need to do some homework before you destroy the head trying to extract it. Do some searching here and you will find all of the information you need to try and drill it out. Good luck.

Don't force any more of them. They seem to break at about 45 NM of torque or so...if you have to apply more force than that try other means (freezing them or impact tools) before you break another. This is precisely why I don't recommend R&R of the GPs unless they have failed...you now have made quite a job for yourself.

I would agree with the other posters. When I did mine, I used plenty of PB Blaster and a product called Freeze-Off. If your plug is free of the threads, and you still have resistance, it might just be the carbon buildup holding the tip of the plug. When I did mine, I used a deep 6 sided socket, with an extension, and it allowed me to apply outward pressure while I moved the plug slightly back and forth. I also used a torque wrench to insure that I did not apply too much force to the plug. I think Beru lists the breaking torque of their plugs at around 45 n/m. Good luck!!

Sorry to hear that the plug is broken, and I wish I had a quick and easy solution to your problem.

Although the manual seems to indicate 33 ft-lb. or so for the plug.........I've got the suspicion that they take quite a bit more than this value before they fracture.

Obviously the data is not readily available, but, I'd suspect the plug would need at least 45 ft-lb. to break it. As an example, a .375 SHCS will take 48 ft.-lb before it yields..........and the plug should be equivalent to a .375 screw or better.

While no help to the Muleears, post 17 in this thread indicates the breaking point of the Beru plug is ~85-90nm.

http://www.peachparts.com/shopforum/diesel-discussion/205418-om606-glow-plug-replacement-pray-me-please-2.html?highlight=glow+plug

I believe the MB extractor kit has extraction bits designed to grab the insde of the GP case in instances where the guts shear off at the heating element? Also, I seem to remember some other extractors being posted that looked worth a try before attempting to drill it out.

Yep, thanks Terry. I knew I recalled that from someplace.

So, figure 60 lb.-ft. as the limit..........cannot break the plug at that level.

M-B now has a tool to remove the stuck plug from the head. You might be able to find a dealer with that tool. You almost certainly don't want to buy it yourself as it is quite expensive.

this is just a thought... i have not had this happen but... what about a easy out?

You have to drill a hole to use an easy out. Don't drill into the head. And don't break that easy out off in the plug.

I know that you don't have this tool, but it might give you some ideas regarding your glow plug problem.


http://www.youtube.com/watch?v=koghDoROFko

It is broken immediately below the hex section. It snapped first so it hasn't backed out at all. There is approx. 1mm of plug outside of the head.

I guess the next step is to pull the hex section and the guts out of it so I can attack the balance of the plug. Will the guts pull out or will they have to be drilled.

NHdoc, believe it or not I subscribed to your advice about only pulling bad GP's. In this case both 4+5 had gone bad within a week of each other. #4 which came out easily was a Beru. Don't know what stuck #5 is yet. I wonder if there is a correlation between manufacturer of plugs and sticking frequency?

Argh! Ok, then it was just bad luck...can't really help that. Look at it this way - if you do land up having to pull the head you can do the other 4 now and be done with them.

If it happened to me I would stop by the dealer and talk to the SA and see if they have a tech with a lot of experience dealing with broken plugs. If my local dealer couldn't help then I'd call around to dealers near by.

It might be worthwhile paying them for an hour or two to extract it if they know they can do it without resorting to "off with the head". There is no substitute for experience...any job that you do all the time is much easier than it is the first time.

It would be interesting to know the brand of the stuck one. I know mine are all Beru and have heard of a couple of Bosch that have gotten stuck...anyone broken a plug know if it was a BERU or Bosch?

The offending plug. As you can see with it broken right behind the hex section there is very little sticking out of the head.

Whats next, pull the rest of it out?

Hi

My advice would be to leave it alone and do nothing else with it. The car will start on 5 plugs albiet a little lumpy. It could save you a lot of hassle. Parrot of Doom has one of his welded in place by a previous owner who obviosly decided it was too much hassle to go any further. You might not need to weld it in place me feels:)

McCool300TD

That broken plug is a Beru. You can tell by the connector.

It looks like you've had the wrong socket or a bad angle of attack??? The socket has slipped and scored the head of the plug.

BTDT!!

Here is my experience - http://www.peachparts.com/shopforum/diesel-discussion/109101-e300td-glow-plug-stuck-broken.html?highlight=glow+plug+drill

and here is a webpage that Alan McReynolds did that might also help - http://alan.mcreynolds.googlepages.com/howtoremovebrokenglowplugs-mercedesom606

Terry, yep I had a bad angle and rounded the corners a bit. Finally got it on straight and broke it off:rolleyes: I may have been better off just rounding it:mad:

Sokolof, I have read your thread in the past with great interest and apprehension, hoping this would not happen to me, but...

I think I will leave it as is for the time being anyway. When I break off a second one I guess I'll have to do something.

Slightly OT: When removing the IM I found that the bolt (attacked from the bottom of the car) that attaches to the EGR is missing! This begs two questions: A) anyone know what size/thread/length this bolt is or is it a dealer only part? and B) just how important is this bolt anyway:eek:

I'm trying to keep a positive attitude about this... I love the car but... GP's, belt tensioners, engine mounts, air leaks, ball joints... all since august. I guess I'll just have to chalk it up to poor PM by the PO. OTOH I guess it was about time for this stuff to go anyway. Hopefully I'll get caught up and not need to do anything for a while. I do drive it 500+miles/week, I shouldn't b!$@h.

Some can live with it as-is...if you're one then do that. I'm not - I have to have everything work as it should so it would drive me nuts. I'd have to either fix it or sell it, but I know I have a problem that way.

You live in a warm enough climate most of the year that the bad cylinder will start firing farily fast. Still...to me it is worth trying to call or stop by your dealer - if you are lucky they will not be a-holes about it and will take pity on you. We know they must break them all the time...there is probably one guy who has removed 50 of them working there who could do it for you. What have you got to lose?

All of the stuff you mentioned doing since august is typical of these cars. I mean asking a 10 year old car with 160K miles to not need anything is asking alot.

That bolt is a M6x16.
http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=210225&M=606%2E962&GA=722%2E608&CT=M&cat=19T&SID=14&SGR=045&SGN=03

*edit* Note two sizes are shown for part #170 on the diagram. The first is 6x16 and the second is 6x20.

The one that attaches to the bracket and the pipe into the EGR?

Just get any old bolt and nut and make your own. Thats what I did. The metal on the pipe is quite soft so use a big washer.

Also check the other one at the other end of the pipe. That was missing on mine too.


As for your glowplug, if you can afford it take it somewhere and have the head off and it drilled out. If you can't afford it now, just leave it alone. It won't harm anything, it'll just be lumpy for 10 seconds on a cold morning.

I just had a thought. I know, for me thats a dangerous thing, but here goes.

Since I already have one broken and the others are unknowns, should I take them all out and see if any others stick so I can rectify them all at once? If three stick (and break) and I have to pull the head I'd rather do it once than pull the head three times if I change them as they die. Am I making any sense? If all the others come out I could do some PM and slather them with anti-seize before putting them back or replacing them with new. Is the anti-seize route beneficial to prevent them from sticking? How about taking them out once a year and renewing the anti-seize?

I just read in lightmans glowplug thread that the valve cover cover bolts are the same as what I need.

that was cool.. Very informative on how the broken plug is removed


would some form of slide hammer help in removing the plugs. Ya know, to loosen any carbon on the tip that is holding it captive/

Another moment of silence for those that have gone before I.

Lucky for me dealer replaced them without incident 3 years ago.

But I will probably tempt fate at some point and pull them. Many here shudder at that thought.

Hope it all works out!

Wish me luck: Broken GP removal today.
 

I broke a GP in my W210 last week. I have found an indy in my neighborhood who has a tool to remove such plugs. I am not sure what kind of "tool" it is. We are going to attempt this today. I think at the same time I will remove all the others and replace with new and cover each with anti-seize. I also plan to begin a regular removal regamin to avoid this in the future.

Good luck. I watched a video that Forcedinduction posted showing a broken GP being removed using a special set of tools. It looks VERY time consuming.

http://www.peachparts.com/shopforum/diesel-discussion/201959-will-cdi-repair-tool-work-606-a.html?highlight=glow+plug+tool+video

Mine failed exactly the same way last night. I am in the process of drilling & tapping it.

I'll let you know how I make out, good luck to you!

Cal, I just got mine out.

Drilled it & tapped it to 5/16, then used a threaded rod & socket as a puller.

More info and pictures here:
http://www.peachparts.com/shopforum/diesel-discussion/88574-finally-step-step-glowplug-change-98-99-e300-9.html

Good luck man!

Good job.

Did you use use a jig of some sort to establish the angle for drilling or do it by eye?

http://bp2.blogger.com/_p71v9ofBM6w/...s400/wohoo.JPG

I set a GP in the hole next to it, so I could eyeball the angle. Then I started with a small bit and drilled a hole in the electrode that goes down the middle. Doing that, you can pretty much see if you are wandering.

I did make a scary mistake: busted a small drill bit in the GP. I started too small, which worked fine on the "test run" in the vise, but was harder to keep steady in the head. Taking my time, I was able to use a punch to get the remnants of the bit out, as long as I stopped drilling every 15-30 seconds. With that in mind, I wouldn't start with anything smaller than a 11/64 bit

A jig would be a really great idea. maybe we could get someone to fab them up. I'd certainly buy one, just to have handy. They wouldn't be much good for scenarios like Muleers or mine where the head broke off, because you have to eyeball teh angle to get the threaded "neck" out. That's tricky.

But for the more common situation where the threaded portion comes out, leaving the body behind, a jig would be ideal. You could screw it into the GP hole, and run a drill bit down inside... nice & straight.

I'd pay $50 for one, easy

Mine was scheduled to be removed with a "tool" another individual had found and bought for $400. His car had a broken plug too. I have not yet seen the tool. I will share the info on it when I have it. If it works well it may not be a bad idea for 8-10 of us to buy one as a group.

We did not get to my GP's today. We were doing the belt tensioner pulley first and broke two allen sockets trying to get the pump pulley off. I will continue my saga tomorrow, wish me luck.

notfarnow: my 210 has a greasecar kit and is running great (except the plug of course)! I used the three valve setup not the standard two valve.

Cal - What are you doing to your tensioner?

I've done mine a time or ten and have got it down so that I can pull the belt, tensioner pivot arm and associated peripherals and put it all back together in 45 minutes start to finish.

The bushing on the pulley is bad. The problem right now is the allen on the water pump pulley. Didn't get to work on it at all today. I'll have to drive the 87 to work.