IMO, there are reasons.

1. Assuming that you haven't replaced them for a long while and 1 burns out, it is likely that the others are not far behind. Save yourself the gasket $10-15 and the time, routine or not.

2. If you take it out after a long while, you can re-anti-seize the plugs and clean the threads.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

I think the glow plugs cost more than the gasket. And, I have taken to reusing the gasket once before I ditch it. I tried it the time before last and had no problems. So, I don't see how replacing functioning glow plugs saves money.

Pulling them when they are the least bit resistant and then reinstalling them is a formula for going back in to replace the plug sooner, as I see it. I would prefer to install only out of the box, new plugs. Can't really tell if the removal process did any structural damage.

So, I hear you aklim, but I am inclined to fix only what is broken. Besides, the intake manifold is getting routine now. Still hate it covering everything that needs regular work, but it is not that big a deal thanks to Lightman's instructions. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Well, I have never reused a gasket and don't know of any shop that will do it. I wouldn't myself just because it is cheap enough to replace. Now, if you had to pay to get it done again, you'd be paying for the labor. Same as if you did it yourself. It is still your time to go in again. Yes, you can go in again but why do it? Now if the plugs are newer, say with 10K on them, I would probably replace the bad one. I tried that with the plugs when I had a bad one recently. A month later, I found myself replacing the next one. At that point, I just changed the remaining 5.

Having the car down and the wife wondering why the hood is up is.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

I have resigned myself to changing a plug or two every year or so. Seems they never fail in the summer.....

If I was paying the dealer or another mechanic I would reconsider my perspective. I find the job tedious and irritating because of the intake manifold, but not difficult, complex or more of a risk.

The gasket is metal. You can inspect it and see if it is damaged or not. Mine look about the same when they come out as when they went in. So one has been back in twice.

The choice is just that, a choice. Just did a single plug, number 3 I believe, about a month ago. A couple have now been in for a few years. Most are less than three years old. But my choice is not about the cost of a gasket or the plugs, primarily. For the most part it is about leaving the things alone until breaking one off happens because it was not functional and I had to replace it. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I have always believed in changing all at the same time. In my case the good plugs came out very easy. #3 still has resistance (if i measured correctly I think I got just under 4 ohms), #5 and 6 have no resistance at all.

I am at a point where I will just wiggle back and forth as long as it takes. I ordered a better penetrating oil according to Ohlord called Kroil. I hope to get it within the next week.

As far as taking off the head, in case I have to plan for it, how hard is it?
And how hard is it to align the timing afterwards, I have never done a head job before. Anyone out there competent to do the job in my garage?

I think I have a few options:

1) keep going (taking the plugs out) until I succeed.

2) failing with a broken plug - at which point I will have to try to drill it out.

3) Having read Aklim's drilling problem, I probably will not do #2.

4) Stop while no plugs are broken and take it to the dealer or a local indi to get the plugs changed.

I already know that the dealer charges 1000 dollars to change the 6 glow plugs. I don't know any indi shops that I could try. Does anyone have any suggestions? If I go to anyone, I probably won't be guaranteed that the GPs won't break off. If they break at the dealer, am I right to assume that they will charge me to take off the head???

Thank you all for your support.

__________________
1998 E300 Turbodiesel 184K

I am not sure the resistance measurements you are reporting are within the range of "good" plugs. As I recall, they are typically around 1.1 Ohms, plug alone, and can be as high as 1.8 or 1.9 Ohms measuring from the glow plug power distribution connection (the black plastic plug on the fender that goes to all six glow plugs in the engine) to ground. 4 Ohms sounds like something is fishy. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Taking the head off is a serious task, no doubt!

Even if you end up with a broken plug, it won't automatically mean you have to take the head off.

Here is an excellent example of how to get yourself out of trouble if it ever happens to you:

jakesbenzconversion

Even if the threads get damaged in the process, you'd still have the option of inserting Heli-Coils or Key Inserts threads (although I don't know if that is a factory approved repair).

Good luck.

__________________
BigBen

'98 E300 Turbodiesel 244 000km
RIP '92 300D 2,5 Turbo 632 859,4km due to engine failure

Yes it does unless you are that good with a drill and it is in a drillable location. I almost had to buy a new head from drilling and that was with a couple of MB techs doing it. Luckily the machine shop was able to redrill a seat a little deeper. Head removal and paying the machine shop to drill it out is a lot cheaper than head removal and head purchase.

I think it is. Their repair kit has heli-coils.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

First of all, relax. You are getting worked up about this and so far nothing has gone wrong.

Secondly, no mechanic will be able to get a stuck plug out without breaking it off any better than you would (in fact I'd bet they are MORE likely to break it) so to pay someone to break it is silly. And yes, if the dealer or indy breaks one they will charge you for the time it takes to replace it whatever is involved, so you have nothing to lose by continuing yourself and hoping for the best. The odds are with you as most GPs do come out without breaking. If #3 is now turning that is a very good sign.

I'm not sure Kroil will work any better than PB. Kroil is excellent at busting rust but you don't have a rust problem, you have a carbon problem most likely. I don't know if any of the PB is getting in far enough to lube the point where the GP is binding or not, but if you can turn the plug back and forth, even just a little, I would continue to do that and apply PB, and each time try to unscrew it a little further. I'm confident you will get them all out. Even if one breaks you are still in the same position you'd be in if you brought it to a dealer or indy...just take a deep breath and keep trying.

As for the removal of a broken plug, many people have reported success in removing them WITHOUT having to resort to removing the head. Cross that bridge when you come to it, but I'd bet if you did break one and had to resort to drilling you could get it out without having to pull the head. Since AKLIM's incident there have been many more cases of broken plugs and much more experience at extracting them without head removal.

RELAX!

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

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

That kit/procedure is for the CDI, I wish there was such a kit for our cars!

Here's an excellent write-up for our engines I bookmarked:

http://www.peachparts.com/shopforum/showpost.php?p=1707350&postcount=51

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Wow, I feel like a netspert now! My drawings are crude but I couldn't get clear pictures that explained what was going on.

I saw that when I busted my plug. I wasn't very comfortable with the idea of a slide hammer. I found these links where they make an actual puller, and that's what I did and documented in the link above

http://alan.mcreynolds.googlepages.com/howtoremovebrokenglowplugs-mercedesom606

http://www.peachparts.com/shopforum/showthread.php?t=109101&highlight=606+%22glow+plugs%22

I'll tell you this much, I have NEVER lost so much hair in one weekend. Talk about spooky.

Just the same, I would say this is not beyond the reach of the DIYer... I am certainly not particularly talented. Just be REALLY carefull with the drill. Put something long in an adjascent glow plug hole and use that as a visual guide to keep the drill at the right angle.

__________________
Jake
1999 e300d PlantDrive WVO/SVO conversion
**note to self: oil changed at 268k kms**
1990 Toyota 4Runner FrankenDiesel swap

I didn't touch the car on Monday, so I went back to it last night (Tue).

I put the torque wrench on the hard to move glow plugs and I was amazed how much easier it was to move them. The torque wrench is also 4 times longer than my 3/8 inch wrench, so the extra leverage surely helped. I thought somehow that the carbon might have softened a bit from Sunday's work. (the setting on the torque wrench is ~48 NM)

I decided to use the 3/8 inch wrench and the GPs were very hard to turn. That is when I realized the torque wrench gave me the feeling that maybe I loosened some of that carbon.

I can see half the threads from #5 and 6 GPs. I haven't turned #3 out more than one or two revolutions. I will wait for the Kroil to arrive sometime on Friday until I try again. Its a good thing I have a Toyota Camry as my 10 yo reliable vehicle to drive while my MB is in the garage.

Can the Oil filter housing be removed so I can get easier access to the #6 GP?

Thank you.

__________________
1998 E300 Turbodiesel 184K

when I did my 96 e300d, it took me 6 days to get all the plugs out. I used PB Blaster, and another product called Freeze-Off, which is available at almost any auto supply store. I used the torque wrench with a six sided deep socket, which allowed me to apply outward pressure to the plug while turning it. Your plugs are carbon bound, and if your are free of the threads, the carbon has a grip on the plug tips. I would squirt some Freeze-off for about 35 seconds, which lowered the plug temperature, then I would hit it with PB Blaster, and just give it a little turn back and forth. As I said, it took me 6 days to get them out, but they all came out with no breakage. Good luck!!

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96 E300d

Hello everyone,

I unscrewed #3 and #5 GPs to the point where the threads are outside the head. The plugs move somewhat easy, but they are not coming out. I am thinking of putting an air ratchet on the GPs and spin them while I keep spraying KROIL, et al. in there... Maybe I can even use a pipette and put some biodiesel to drain into the space to try to dissolve the carbon gunk.

#6 is half way out, I'm sure I'll get it unscrewed like the others, it is just harder to work on with the oil filter housing in the way.

I definitely had more luck with a warm engine. At one point while the engine was warming up, I put the ratchet on the GP's and started turning. I was surprised how much easier it was to turn (although that could have been just from the heat).

Has anyone gotten to the point I am at with #3, #5 (threads out, but plug not coming out) and tried to start the engine? I am affraid of launching the GP's into my neighbor's house, so I just want to see what others have experienced.


Thank you.

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1998 E300 Turbodiesel 184K