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

Maxbumpo · #76 04-12-2016, 07:13 PM

I get a "file failed to upload". I've tried various file types and sizes, same error.

mikemass1221 · #77 04-12-2016, 08:12 PM

Ok guys. Here are some photos and depth measurements. I took some shots from different angles so certain ones appear off center, which they probably are. And yes, I know I broke the heat exchanger. That's the least of my worries right now. It's a $100 part I will deal with when and if needed.

First we have a wide shot which is somewhat straight on:

Next is one zoomed in a bit taken slightly from the left looking right. Note in this one the "cavity/black hole" area to the right. This is not where the coolant came from. I believe this is actually where the GP should seat, because if I probe around in there with the tip of a drill bit it comes out with carbon. The coolant started spewing from the neat smaller hole made with a 13/64 drill bit to the left.

Next is a picture with a drill bit in place so you can see the depth. In this pic the bit is bottomed out beyond the 13/64 hole. I measured that at about 2-7/8 inches from the face of the head. Yikes!

Next measurement I took was drill bit in place, but not going through the 13/64 hole. I rested the bit at the level above that which measured about 2" from the face of the head, So in other words, the hole in the water jacket is 7/8" deep (hope that makes sense). I don't have a pic with the bit level a little higher. But the measurement is accurate that I am giving you.

Lastly I will just throw in some more pics from different angles where the light picked it up differently:

mikemass1221 · #78 04-12-2016, 08:19 PM

And lastly and excellent cross section photo provided by Maxbumpo.

It appears the are indeed angled slightly "down". I don't know where the hell I drilled. But take a look. Tell me what you think.

funola · #79 04-12-2016, 08:33 PM

Not sure where the coolant passages are in the diagram. Maybe Maxbumpo can point them out? I assume it is the 2 non shaded areas under the glow plug (all white) that are the coolant passages. The small drill bit looks not centered and on the bottom of the hole. Is that true or an optical illusion? If so and if angled downwards could have drilled into the coolant passages depending where they are.

If you have a glow plug on the bench, you should be able to roughly determine how far and where you drilled into the head.

renaissanceman · #80 04-12-2016, 08:47 PM

Looks like you cut into the coolant passage below the glow plug...so at this point, if the remnants of the glow plug could be removed, then this would have to be reconstructed somehow.

1st order of business is getting the glow plug out if you want to mess with this car. Then deal with plugging it. Good news is that there (seems) to be no damage done to the prechamber/piston/etc.

If you want to keep the car, we can keep the ideas flowing.

mikemass1221 · #81 04-12-2016, 08:51 PM

Nope not an optical illusion. I definitely drilled low. Now that I am really inspecting these pic I am wondering. 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 could not see this with the naked eye. But with these pics nice and zoomed in, I am thinking that is the GP.

funola · #82 04-12-2016, 08:56 PM

If you have a long straight rod that fit in the small hole snugly, you should be able to "sight" where the drill bit was aimed

mikemass1221 · #83 04-12-2016, 08:58 PM

Quote:

Originally Posted by renaissanceman

Looks like you cut into the coolant passage below the glow plug...so at this point, if the remnants of the glow plug could be removed, then this would have to be reconstructed somehow.

1st order of business is getting the glow plug out if you want to mess with this car. Then deal with plugging it. Good news is that there (seems) to be no damage done to the prechamber/piston/etc.

If you want to keep the car, we can keep the ideas flowing.

Hell ya! Keep em coming. This may turn into a multi month project. But now I want to see where this journey can lead. The knowledge here on this forum is great. You guys are amazing.

The early bickering aside. Every post was VERY worthy. I am a very visual person and even though the two cross sections provided earlier were not of the 606, they both gave me an idea of what the innards could look like. Please don't knock one another. I am the idiot here. Everyone's input is welcome as long as it is a well thought out thesis.

No one is going to agree on one method. That's okay. Remember, if everyone is thinking alike, then no one is thinking.

renaissanceman · #84 04-12-2016, 10:38 PM

Start by drilling in the center of that circle and tapping the plug and removing with the threaded rod method detailed all over the interwebs.

Then we can see about cleaning it up and fixing the first inch or so that is FUBAR.

pgringo · #85 04-13-2016, 12:00 AM

This thread is officially better than TV for sure.

Sent from my SGH-T889 using Tapatalk

ROLLGUY · #86 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 · #87 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 · #88 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 · #89 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.

mikemass1221 · #90 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.