In my endeavors to change my glow plugs I have had a set back. 3 of my 6 came out with little effort, and 3 are stuck and the bolt has been sheared off. I let the plugs soak for about 30 min. with PB Blaster before I even tried to unscrew them, and that seems to have not helped at all.

Any ideas how to get the 3 stuck plugs out? The stuck plugs are 1,3, & 4 front to back.

Thanks,

If you really broke 3 of them off then things are looking ugly. Out comes the head and off to a respectable shop, MB has a tool just for this now.

Once they are out take them out and anti-seize them every year or two.

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raMBow

1999 E300DT Obsydian Black Metallic, Heated Full Leather Parchment options, E2, K2, 136,000+, best 36.5 mpg - GP's 12-04 & 11-12 Zero Stuck
2010 Honda Odyssey - The BrideMobile - best 26.5
(2) 2005 Honday Accord- (1 -Corporate 1 - Personal) - 110,000 4-cyl 30mpg
2000 VW Golf GLS TDI, Upsolute Chip (sold to Brother, now 300+k on it) 48.5 mpg like clock work
1987 Honda CRX HF - Sold 87,000 always over 50 mpg Max 67 mpg

30 minutes with penetrating oil is long enough for some jobs, not for others. Some take hours, or days with multiple applications.

By "sheared off," do you mean the flats? If so, you may be able to get them out with locking pliers, after enough time with additional applications of penetrating oil.

You might be able to drill them out.

See http://www.peachparts.com/shopforum/showthread.php?t=109101&highlight=glow+plug+drill

Len

drilling out a GP is very very risky. You could wind up leaving bits of metal in the combust chamber, then you will have problems when you go to crank the engine.
Or you could damage the threads in the aluminum head then the new GP won't go in without chasing threads, again some risk.
With three busted GP's I would plan on sending the head to a reputable shop, one that has experience in this. I saw a machine shop where they were removing the remnants of a GP in a 606 head. The MB Dealer sends the heads there when they bung them up
The proper way to machine a GP out is to set the head perfectly flat in a fixture with an overhead mill and step machine it out using reamers until most of the metal is gone then chase the threads out with a special tap (by hand!)
I would be too nervous to try tapping out one plug with the head on the engine much less three, just thinking about the price for a replacement head I might go nuts worrying and clam up $$$$$$$$$

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Thanks for all the wonderful news, LOL. When I say sheared off, the plug in its entirety is still there, the nut that one puts your socket onto just spins, so I am guessing that the nut has broken off the glow plug, but the entire glow plug is still there.

Had an idea of hitting the nut once or twice with my welder to reattach it to the glow plug, however not sure how much one of these glow plugs can take, it looks like they are made out of some soft metal.

My other idea was to get some vise grips onto the glow plug and see if I can get them to spin out. I think I need to go buy some needle nose type to get in there.

Just looking for some ideas on how to get a hold of plugs, since the top is that shiny silver tip, which does not lend itself to getting a good grip.

Oh yea, forgot to say that this car has a grand total of 52K miles, would not think these bad boys would be stuck in this bad.

Keep the ideas coming guys, thanks.

I believe they get stuck from not being seated well enough and not quite all the way tight. Soot and the like eventually make their way past and seize them up. I would talk to the guy in the thread attached in a few posts up.

Exhaust your options but do not ruin the head!

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-disav

99 E300 TURBODIESEL Astral Silver 282K - AMG brakes, suspension, monoblocks, speedo & interior - Full Load Maxed on IP by custom Speed Tuning USA Chip - T3/T4 Garrett - EGR/MAF delete
98 E300 TURBODIESEL Alexandrite Green on black leather 289K
95 E300 DIESEL Green Queen 267K SOLD
84 300D 216k SOLD
87 300D 299K #22 head - intercooler - full load adj. - 8sec 0-60mph - SOLD
76 300D 214K SOLD

Some good news, was able to get the #1 glow plug out with a bolt out tool, so now I am just down to 2 stuck plugs. The bolt out will not seem to budge #3 or #4, and there is not much to grab onto on the #4 plug.

The center rod which I am guessing is the electrode is still sticking out, guess my question is, is that electrode attached to the outer casing, or does it just slide inside? Was thinking that if I could get something on that electrode, maybe could use that to turn, just a thought.

Not really scared about drilling out, it looks like there is room, and risk of getting shavings inside, looks minimal, but would have to cut the electrode off in order to get a drill bit inside the shaft. Essentially all one is doing really is drilling out the electrode, just not sure if is is attached or not, hate to push electrode down into chamber while drilling.

Any more ideas, keep them coming.

Once we used a big enough drill bit my stuck glow plug came out easily and all in one piece. There's a picture of it in my post above.

Len

They get stuck because of carbon buildup along the sides. The thread will likely be fine.

I would echo what everyone has already said. Lots and lots of penetrating oil. Also try Loctite Freeze & Release. Oh, and time. Lots of time.

Oh, and I know somebody who had the same problem. Fired the engine up and the glowplug ended up stuck in the garage wall I wouldn't recommend you do that though!

I really like that method...just make sure nobody is standing downwind of the intake side of the engine when you fire it up!

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

AND that the hood is raised to verticle position....

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

If you cannot get it out, pray real hard that you drill it just right. I was lucky and drilled it sideways and they could save the head by drilling it further and retapping so I have 1 GP that sits deeper than others. I should have taken it to them when it got stuck. I am fairly certain that it is NOT the carbon since all the GPs that came out were not sooted up and the prechambers were removed and pretty clean. It was the dis-similar metals that siezed.

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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

The real issue with the 606 engines is that the glow plugs are longer then the 617 and 603 plugs, and they look thinner but I've not measured any up to verify that hunch
MB has a real problem with them sticking in the heads though and I believe if they used some antisieze on the threads at the factory some of the problems would be lessened but the fact that the carbon builds up inside and they get stuck will always be something that will be present.

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

If true then please explain why we don't seem to have ANY instances of stuck glow plugs on OM601, OM602 or OM603 engines.