Welding the tool would be too much heat on the head. I had made a thread chaser of sorts before by beveling out some channels on an old injector body. Would the tap work better? I am thinking getting the threads as receptive as possible and JBwelding the tool in over night. Is there anything better than JBWeld?

The holes at the bottom of the Prechamber are not not so big and the Prechamber could be stuffed with Toilet Paper to prevent things from falling inside.
If the threads on you Tool Are stripped it might be a bad idea to try.

Was your Prechamber Tool a Real one of was it one of Mercedes resourses Bicycle Hub Pullers? Or a Homemade Tool made from a Bicycle Hub Puller?

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84 300D, 82 Volvo 244Gl Diesel

It worked on an undamaged prechamber on my 300k miles merc. I wanted one of those bicycle hub pullers because they were cheap. It was from baum tool and came with a slide hammer. The threads on the tool are bad enough that I would never use on a good prechamber, but their still pretty good. Its the prechamber itself that is mangled.

I am holding off on doing anything today (50 minute round trip to get to the car). Do you think I should reuse my home made chaser to get the threads in the best possible shape? I could try to acquire a tap, but my thinking is that might be worse at this stage. Use something better than JBweld. I stupidly have used the quick version in the past and was not impressed.
Things better than JB weld:
1. "autobody panel adhesive"
2. Loctite 324 industrial adhesive $20 for a small bottle and another $30 for the Loctite 7075 spray activator
3. Couple of spots of 3M 4200 UV cure to hold while a nice bead of 3m 5200 sets, maybe $12 a tube each (urethane). Urethane is used to join body parts in production, and it is generally more flexible than epoxy. I have heard than urethane glued body joints can be stronger than the steel they join.
4. Based on my experience of fixing stuff that seemed nearly hopeless, I would recommend PC7

I am leaning to the 3M 5200 because its got some flex and might be less likely to break with slide hammering? (what do I know). 7 days to set though! Suggestions anyone.

This worked. It probably would not have been necessary if I'd removed the glow plug! I guess if one bought the tool and legitimately could not get the prechamber removed after one attempt, then I'd epoxy since the tool is probably damaged too at this point.

Getting older and I am clearly going to have to become super methodical with notes. Did a test removal on older car and took the plug out first. Thought I'd done so on this car. In my defense the glow plug wire was attached with a much smaller nut (nut built into harness missing). I am still shaking my head on this.

Didn't notice the glow plug issue until I had the intake manifold off. Replacing shutoff valve today and putting back together. May the maker help me from another Mr. Magoo foul up.

Car is up and running. Prechamber pull and replacement has been a success. Now, I've got to return bunch of parts for the aborted head gasket replacement.

X2 on the getting Old issues.
It seems like all the things I do these days are much harder then they used to be.
Some of the issues are Physical; lack of strength and dextarity and some Mental; especially when it comes to remembering things.

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84 300D, 82 Volvo 244Gl Diesel

I seem to remain as systematic as ever so farat 70. Just slower to initialize and get a job wrapped up. Twenty years ago if a load of parts came in for one of my cars chances are they would be installed in the next twenty four hours. Now I may not even get to it for a week or so. Results in an almost continuous line up of things to be done.

I would suggest selling me the 603IP and swapping in a junkyard motor, or a 606.

Have you consulted a machine shop? They may be able to coax the prechamber out.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

I'll call them tomorrow, tow the car down if they think they can get it.

If you do a complete cylinder head rebuild, you will be rewarded with:

An engine that uses 1 qt every 500 miles.

An engine that may bend rods due to new found power.

Really, having good valve sealing on worn rings will draw lots of oil into the combustion chamber. Not only will oil consumption increase, compression ratio does too.

Your friend that has worked on some diesel heads, is he a mechanic or someone that has done some at home repairs? If mechanic, is he heavy equipment or light truck?

Him not "skimping" and wanting to throw every part at the head could be considered not knowing what parts are worn but are reusable Vs what parts are too worn to continue. Another consideration is that heavy equipment engines need to run at full power for extended periods so they need better parts what would survive in a lightly loaded automotive app.

There is always a risk in patching up a worn engine and something will always be left undone. If you do all those "just one more things", you end up with a rebuilt engine.

So, if this engine was running and driving, would you have removed the head for a total rebuild? If not, pull the head, change the prechamber, look the head over for obviously burnt valves and reinstall. ( exhaust valves will always leak a slight bit on a worn motor )

The next step, if the car is worth while, have a spare engine waiting ready to go. A 606 swap is probably beyond your level due to mods needed, but a 3.0 603 is supposed to be a drop in, others can speak to the specifics.

Great advice. This confirms my gut feeling which is don't fix it if its not broken especially with this of all engines. Bert the Troll making stew, "Just needs a sprinkle of squirrel dung.... Ooh. That is beautifully balanced, that is."

Its a hard call. With luck welding/gluing the prechamber to the removal tool may work.

If no, what do you think of knocking out the prechamber out with wood dowel and hammer from behind once the head is out? No experience, but I am thinking one would check the head out after this to make sure it was not damaged by the removal? If the valve seals are still good, would there be harm in replacing them so that they don't fail later? If the seal or lifter is failing and it is left in place, will the continued detioration likely be slow, or is the engine going to be in trouble anyhow within a few years? I am sure its hard to make a call without actually being hands on with the engine. I'd rather lose the engine now while I am unemployed and have some time on my hands, rather than a year from now.

For the record I don't have direct experience in removing these prechambers but I have removed countless stuck / broken bolts / parts as well as having built / repaired countless engines.

I'd do a couple of things, use a heat gun ( torch for those with experience ) to heat the chamber / head a few times. Aluminum expands at a greater rate that steel so the thermal swings might break the carbon / corrosion bond. There is a chance of oil burning when you do this so keep something handy to put it out.

Can you clean the threads and screw the tool in farther? Some other tips. A slide hammer isn't always the best approach as the impacts can tear up poor threads. A U shaped bracket used as a puller base might be a better approach. Take a look at a General Motors steering lock plate removal tool for an example.

It can also help to pull on the prechamber just until it stops moving and no farther, tap it in then pull again. This works the corrosion out of the joint.


Sounds fine to me.


I'll clear up some of my terms as some terminology gets fuzzy.

_Valve SealING_ is a quality measurement. This speaks to the valve face and valve seat. A valve grind cleans up these surfaces so they don't leak air. This is where good valve sealing with worn piston rings causes increased oil use.

_Valve SealS_ are the rubber / metal lip seals that seal the valve stem from oil. These are worth changing if the head is off they can even be changed with the head on if needed. They don't age well and on overhead cam engines show their age earlier than a cam in block engine.

If you're worried about bits in the engine you can probably push some epoxy putty (not the normal liquid stuff) into the PC hole to keep debris out of the engine.

In my mind, welding a rod to the PC and immediately pulling it out while hot would probably work, the heat should(maybe) help it get moving?

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Normal JB weld takes 24-28 hours to set and its great so long as the surfaces are clean of grease/oil and the surfaces are rough enough for the JB to 'grab'.

If you're worried about overheating the head when welding, then just zap 3/8" at a time and let it cool between zaps.

__________________
$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Just spoke to machine shop. They won't work on a car directly, but the guy sounded confident that it could be welded. Stated melting point of tool is probably lower than the prechamber. Would take an experienced welder. He did not have fear of the aluminum head because it conducts heat so well. I am going to call around on this some. Wish I could get someone over with a portable welder. Don't know if such a device would have the heat to weld into prechamber metal.