The best option for repair is installing a used head, or a complete running engine.

Mike: Out of morbid curiosity, how did you get to the point that you broke the glow plug off?

For next time (or next person attempting OM606 glow plug R&R):

http://www.peachparts.com/shopforum/diesel-discussion/376521-om606-glow-plug-removal-tips-tricks.html

That picture is of a OM602 or 603 single overhead cam. The 602/603 have the intake and exhaust valves on the right side and the pre chamber and glow plug on the left. The injectors are on the left so they can spray into the pre chamber. They are in different locations based on the head casting (different between a #14 and a #22). If you look at the inside of the head (top of the combustion chamber) on a 602 or 603 it will not be symmetrical. The 602/603 glow plugs are short and stubby - the total length of the element plus threads is on the order of a couple inches - since the pre chamber is pretty close to the left side of the head. This is similar to the legacy 616/617 engines btw.

On the 606 the dual overhead cams and 4 valves per cylinder make the top of the combustion chamber symmetrical. The pre chamber is dead center and the injectors point straight down with respect to the centerline of the piston. The glow plug now has to reach past the valve train on the left side to get into the pre chamber that is now dead center over the piston. This means the glow plug is now on the order of 6 inches long and the bore walls have coolant and oil passages on the other side.

This explains why the 606 GPs are prone to get stuck - you have about a 4 inch shaft past the threads in order for the GP to be long enough to extend into the centered pre chamber. Carbon builds up between the shaft and the bore walls, and it cools and hardens because of the relatively cool environment especially since there is oil and coolant on the other side.

The OM642 is worse - the GPs on that engine are nearly a foot long...same reason. No pre chamber on a CDI but it still has to get the business end where the action is.

http://i197.photobucket.com/albums/a...DI-cutaway.jpg

best I can understand, you drilled off center, and went into an adjacent water jacket, and it's running out the hole you drilled in the glow hole...

I wish I could find an image of an actual 606 head cutaway... but I can't this claims to be, but obviously it's not.

I spent a bunch of time yesterday looking for a cutaway....no joy. Lots of 617 images but no 606s.

If it turns out that the OPs head is trash, it would be fun to put it on a band saw and see what's actually going on. Might save someone else a problem.

I thought your set screw was placed to plug up the glow plug hole where the flare was. Didn't even consider placing it through the prechamber into the head. How long do you expect that to last? I wouldn't even consider it. Wasted effort IMO.

Sorry, didn't mean to beat him up. It was to understand why he did what he did, learn from other's mistakes.

If I were to do such a job, I'd have a good glow plug on the bench before starting so I can take measurements in order to choose the correct drills and taps.

This pic is a direct injection engine. The 606 is indirect injection with pre combustion chamber. Totally different design.

The ONLY way I'd attempt this drill job is with guides designed for this specific job. No freaking way I'd attempt it by hand!

I had the socket on there and it wouldn't budge. I sprayed PB blaster, let sit, try again, move it ever so slightly, spray more, try to go ever so slightly the other way. Rinse, wash, repeat. On one of the attempts, the nut just broke loose while threads were still in head.

thank you for that un necessary and redundant comment... since I stated in the quoted text that I could not find an image of a 606 cutaway...:rolleyes:

Man, I wish I saw this thread last week. Great write up. Knowing what I know, I bet the removal of the injectors is the biggest key in that process. Getting the PB Blaster in there from that side it the only way to loosen the carbon build up. Which is what causes these to get stuck.

Now I am really upset knowing there was another trick I overlooked.

Isn't it FACTUALLY CORRECT as per the picture that the injector is over the GP?

It took a lot of effort for the PO to drill through the pre-chamber plus the aluminum head, and a looong drill. The head is toasted. What was done was done, move on. It may be possible to remove the pre chamber and plug the hole with a set screw. But with no dis-respect to the PO, I would leave it to the professional.

Then a 617.xxx pic would have been better than pic of a direct injection engine, where if you drilled through the glow plug, it would go into the piston (if at TDC), not into the head's coolant jacket. Equally bad in destroying an engine.

Still feel my comment unnecessary and redundant?:confused:

I take no disrespect at all. I am a weekend warrior. From now on oil changes and brakes jobs is about it for me.

Yes. Lots of effort and stupidity. Once the GP broke, I should have stepped back, taken a break, done more research and re evaluate. Instead I went ultra aggressive with the drill.

Unfortunately, Yes :(