OM 606 Drilled too deep trying to extract a stuck Glow Plug - Page 6 - PeachParts Mercedes-Benz Forum

Maxbumpo · #1 04-13-2016, 01:05 PM

Quote:

Originally Posted by mikemass1221

Do you thing the center of the glow plug is the circle at about 10 o'clock to the drill bit? I am thinking yes.

I agree. I think I see an inner circle (glow element) and outer circle (body).

pgringo · #2 04-13-2016, 12:00 AM

This thread is officially better than TV for sure.

Sent from my SGH-T889 using Tapatalk

ROLLGUY · #3 04-13-2016, 01:12 AM

From the photos it looks like there is a breach of the coolant passage to the right and also below the drilled hole. It also appears that the large hole (the first 3/4 of an inch) is much larger than the threads of a glow plug. The large hole also appears to be drilled low and to the left (already stated). I think if the hole was not drilled so big, there would not have been a problem. However, that is water (coolant in this case) under the bridge. I would agree with others that the head is not repairable, but that it may be able to be patched (plugged) so no coolant gets in the cylinder or out of the glow plug hole. Running it with 5 glow plugs is not the worst thing that can happen. I would say that if any more drilling or attempt to remove the remaining part of the glow plug will set you backwards more than plugging the hole and driving the car till all the plugs go bad so it will not start. As far as the fuel heater, I would just abandon it and bypass it for now. No sense spending the $ on a part that should not affect the engine's ability to start or run.

barry12345 · #4 04-13-2016, 02:34 AM

Seven eighth inch casting thickness is really good if I have that right.

Also not running a normal tap through totally might present a good thread interference point in the hole for a plug. . Trial and error to get it right but not hard. Others will have ideals.

mikemass1221 · #5 04-13-2016, 09:23 AM

Do you guys agree with me that the Glow Plug is that perfect circle above and to the left of the drill bit? (10-11 o'clock position?) If that is the case, my large entrance hole is so off center that it would not only involve tapping the center of the GP and still trying an extraction, but I would have to enlarge the opening even more. It is already 1/2" wide (much larger than a GP thread.)

I can carve out the upper left side of the hole with a carbide tip on a Dremmel to create more room to pull out the GP, but then I would be left with an oblong hole which would make it impossible to ever install a Helicoil or Time Sert.

So here's the suggestions so far:

1. (renaissanceman) - Continue to extract the GP, then worry later about a possible way to patch the coolant breech. Issue here is IF I can get the GP out and IF I can actually patch the cavity, I will be left with the issue of a FUBAR entrance hole to install a Helicoil.

2. (ROLLGUY) - Leave remainder of stuck GP in there as to continue to "plug" the prechamber. Install a Helicoil in existing opening and screw in a threaded "Plug". (maybe in the form of a 1/2" set screw). The coolant cavity I created will still be open behind the plug I install, but from the looks of things as is, coolant won't have any way of entering the prechamber. Downside - I am committed to only run on 5 GP's, but at least I MAY be able to run?

3. (mostly everyone else) Find a refurbished head and spend lots of money replacing or use the wise tutelage of this forum to get me through doing it myself.

Does this sound about right?

ROLLGUY · #6 04-13-2016, 10:52 AM

Yes those sound like your only choices to me. The other choice is to pull the head and weld up the cavity and machine it to factory specs. That is probably more costly than just replacing the head, so that makes it not a worthwhile option.

Maxbumpo · #7 04-13-2016, 01:14 PM

Quote:

Originally Posted by mikemass1221

2. (ROLLGUY) - Leave remainder of stuck GP in there as to continue to "plug" the prechamber. Install a Helicoil in existing opening and screw in a threaded "Plug". (maybe in the form of a 1/2" set screw). The coolant cavity I created will still be open behind the plug I install, but from the looks of things as is, coolant won't have any way of entering the prechamber. Downside - I am committed to only run on 5 GP's, but at least I MAY be able to run?

The issue you'll need to solve is keeping the remains of the glow plug from moving backward into the cavity. Maybe pack with JBWeld before you put in the plug?

ROLLGUY · #8 04-13-2016, 07:19 PM

Quote:

Originally Posted by Maxbumpo

The issue you'll need to solve is keeping the remains of the glow plug from moving backward into the cavity. Maybe pack with JBWeld before you put in the plug?

Packing with jb weld before plugging has my vote too. It could not hurt, the head is too far gone to be brought back 100 percent.

Skid Row Joe · #9 04-14-2016, 02:13 AM

Quote:

Originally Posted by pgringo

Maybe slather some jbweld in there first in case the coolant slowly washes out the carbon then one day *boom* catastrophic failure.

Sent from my SGH-T889 using Tapatalk

Quote:

Originally Posted by Maxbumpo

The issue you'll need to solve is keeping the remains of the glow plug from moving backward into the cavity. Maybe pack with JBWeld before you put in the plug?

Quote:

Originally Posted by ROLLGUY

Packing with jb weld before plugging has my vote too. It could not hurt, the head is too far gone to be brought back 100 percent.

That's what I'm talkin'' about!

Jim Smith would be proud here!

mikemass1221 · #10 04-13-2016, 11:00 AM

ROLLGUY - I can live with your idea. I guess the million dollar question(s) is(are):

Will a Helicoil and a set screw plug hold?

From my photos, can we be sure the coolant is not breaching any vital parts of the engine? Do I understand correct that as long as the Glow plug body is jammed in there, coolant cannot get into the prechamber and/or cylinder, pistons, etc?

If you need me to do another test of some sort to confirm, or more pics, lemme know.

ROLLGUY · #11 04-13-2016, 11:17 AM

If I was in the same situation as you, I would feel fine with plugging the hole and driving it. If the tip of the glow plug was stuck bad enough to break in the head, I doubt it will not seal out the coolant. As far as the plug, I would use a pipe plug and Teflon tape.

pgringo · #12 04-13-2016, 11:21 AM

Maybe slather some jbweld in there first in case the coolant slowly washes out the carbon then one day *boom* catastrophic failure.

Sent from my SGH-T889 using Tapatalk

funola · #13 04-13-2016, 12:07 PM

You need to ascertain where you have drilled into first. It is not possible for us to tell from looking at photos. Have you pulled the injector to see if you drilled through the glow plug and through the pre chamber? Is there coolant in the pre chamber? If you have not breached the pre chamber, that may make plugging that cylinder more feasible. It will lower the compression of that cylinder though since you will no longer have a glow plug tip extending into the pre chamber, which will lower the compression ratio thus the compression. Not sure what that will do to the engine.... more smoke, more vibration, lower mpg?

mikemass1221 · #14 04-13-2016, 12:53 PM

Quote:

Originally Posted by funola

You need to ascertain where you have drilled into first. It is not possible for us to tell from looking at photos. Have you pulled the injector to see if you drilled through the glow plug and through the pre chamber? Is there coolant in the pre chamber? If you have not breached the pre chamber, that may make plugging that cylinder more feasible. It will lower the compression of that cylinder though since you will no longer have a glow plug tip extending into the pre chamber, which will lower the compression ratio thus the compression. Not sure what that will do to the engine.... more smoke, more vibration, lower mpg?

I have not pulled the injector yet. Will this just be a visual inspection? i.e looking for coolant or breakage below the injector? If the tip of the GP is still intact, will I see it? It is my understanding if I try to pull the prechamber out as well, that insures breakage of the tip. Sorry, I just don't know what I am expected to see down there.

Also, no one has commented yet on if that circle next to the drill bit IS the Glow Plug. The reason I keep harping on that is because if it is, it looks pretty intact to me.

funola · #15 04-13-2016, 01:02 PM

Quote:

Originally Posted by mikemass1221

I have not pulled the injector yet. Will this just be a visual inspection? i.e looking for coolant or breakage below the injector? If the tip of the GP is still intact, will I see it? It is my understanding if I try to pull the prechamber out as well, that insures breakage of the tip. Sorry, I just don't know what I am expected to see down there.

Also, no one has commented yet on if that circle next to the drill bit IS the Glow Plug. The reason I keep harping on that is because if it is, it looks pretty intact to me.

If you look at the nice cutaway head diagram Maxbumpo posted, you can see that after pulling the injector, you should be able to see the glow plug tip as well as the ball pin. A normal pre chamber should be dry, covered in a light coating of carbon. DO NOT attempt to pull the pre chamber since the glow plug is still in there, you will cause more damage.

It is hard to tell by photos. You need to have a glow plug in your hand and probe what you have drilled to determine how far you have drilled.