'98 E300 glow plugs stuck in head
 

Hi Guys,
I'm working on a '98 E300 sedan, replacing the glow plugs do to the warning coming on in the dash.

Someone's been in there before, and replaced the first 3, but it appears they didn't replace the last 3.

The first 3 came out easy, in fact, they were barely tight. Plug #4 wouldn't budge, creaking threads in the head.....you know the story, I'm sure. #5 & #6 were the same. Tried PB Blaster around the plugs, heating the head right around the plugs with a MAP gas torch, rocking the plugs a little tighter, then looser, more heat, more PB Blaster, etc. #4 broke at the top of the theads and the "nut" just spins. I got #6 out finally, but it took about an hour. #5 had 3/4th of it's threads out when it finally broke off at the top of the threads and started spinning.

Man, talk about put a knot in my stomach. Personally, I don't see how #4 and #5 can be salvaged. I think they're way too tight for any sort of easy-out type set up, and even if the centers could be drilled (in car) I don't see that freeing them up. They're hanging up due to carbon on the smooth shank areas....even after #6 was completely unthreaded, it would not come out and I had to come with with a way to lever against it and pull at the same time.

So....this is pretty FUBAR and I'd sure appreciate any BTDT input. At this point, I think the smart thing to do is to have the car towed to an experienced Mercedes shop and have them remove the head. (Estimate from one local MBZ Indy is 21hrs @ $100/hr, plus machine shop time, so I'm guessing 3 large when all is said and done.)

There are several posts on successful extractions...before resorting to pulling the head you should explore this as an option.

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

This is a good primer.

This is another one....http://alan.mcreynolds.googlepages.com/howtoremovebrokenglowplugs-mercedesom606

Kartek, Notfarnow and a couple of others here have pushed extraction forward quite a bit recently. Use search and don't give up yet.

A drilling "guide" is what we really need now to ensure the bit goes in straight.

If you get them out I would never seize the new ones so it doesnt happen agian.

You guys are incredible. I was seriously about ready to..........

Nevermind.

Anyway, read through the first set of instructions and will go after this next set in a moment.

I'm going to attack this in the morning, so I'll take photos and post back with my results.

don't attack... This is like a delicate surgery. You have to plan, plan, plan, then go in.

I didn't have as good luck. I drilled and it got off angle so it almost had the head FUBARed. I had the head removed.

Sorry, wrong choice of words.:rolleyes:

And, also ream or use an alternative method to clean out the Carbon in the Glow Plug Holes before you install the new ones.

I used a bronze gun barrel brush to do that.

I was/am Wrong!
 

The Klann kits are for the CDI series engine.
(Thanks! NHDOC,
For pointing out my errors)

Videos of tools in use below

Klann tool kit without thread repair tools:
http://www.youtube.com/watch?v=koghDoROFko
[Thanks! to FI for the link]

Klann tool kit with thread repair tools:
http://klann-online.com/englisch/Filme_E/KL-0369-30K_E.htm

It has the guides and everything.
AND it will be substantially less than Your Indy was gonna charge you,
to R+R your Head.

[Thanks to AKLIM for another post]

HAH! (PICTURE BELOW of the MB kit)[It says Miller]

The Mercedes kit is offered at $1300.00 by local dealer.
AND is for use on the 606.XXX series engines.

Excellent video of that tool in use. I guess I'll call around and see if anyone has the tool, either to buy our borrow/rent, and take it from there.

The Klann kit is for the CDI motor, not the OM606. I don't think we have enough clearance to use a tool like that on the side of the engine. There is a kit made for our engine but frankly the ingenuity of our members in coming up with fixes for this problem appears to exceed the capabilities of the kit from Mercedes. If I had a broken plug I would not bother looking for the kit but would attempt the drill and pull process using home-made tools several of our members have used with success recently.

Anybody know how much that tool is for the OM606? And does anybody around here have one? Is there one in the tool rental program?
Thankfully I don't need one at this time.

I kind of have a nagging question on this issue. Everybody keeps saying use an anti-seize product for the glow plug threads, but aren't these breaking below the threads or are they breaking somewhere at the threads?

This thing with breaking at or above the threads seems to be a more recent issue. When this happens, I believe that either you have to surgically drill and remove the remaining threads from the GP to salvage the threads in the head or just go after it with a drill, remove both the GP and the head threads and then repair it with a Time-sert or a helicoil.

I think more people need to try the "impact wrench set to low torque" method that's been discussed here from time to time.