Well, that had a pinch of a conciliatory tone, and you've stuck mostly to a technical response, so I'm hoping that we'll have a civil conversation from this point.

Many do feel that aluminum blocks are throw-aways, not because they are inferior, but because they are impossible to repair such as when the block cracks. However, the purpose of the liner design was to allow replacement. Mercedes repair manual 01-1100 and 01-1120 and the part number 1190110110 for the M119.982 liner certainly shows that the intent was there. It turns out, the economics is such that liners are mostly replaced in secondary markets by engine recyclers.

As for the key idea, I think a tab or corbel at the bottom of the cylinder would be simple enough, and would allow non-destructive liner removal. Many manufacturers have different liner attachment methods. But, of all of them, I feel interference is the least sturdy.

I do look forward to hearing of your own slipped liner experience. I know that you are inclined to believe that diesel liners and Land Rover liners and gasser liners have nothing to do with each other, but I'm interested in any experience in the matter to learn what the solution was, because, aside from (1) the difficulty of predicting whether the liner will continue to slip or not, (2) the unknown as to whether there is any blowby of combustion, (3) leakage of oil, and/or (4) leakage of coolant, the issue that the OP started this thread for was (5) whether the surface area of the head gasket ring seal would be sufficient to contain combustion and coolant.

In fact, if the existing liner is properly wicked with Loctite 290, and if a shim was properly adhered with Loctite 640, I feel there is a better than 50% chance that issues 1 through 5 can ALL be resolved. Of course, no licensed mechanic could recommend this as a matter of liability should the repair fail. However, I am not a licensed mechanic, so I am free to experiment.

I have never heard of a mercedes 617 liner slipping. I have seen two benz motors overheated so badly that bores were ruined and heads cracked and nary a slipped liner. I don't see it as a possiblility. The OP apparenly has a liner which was too short, IMHO, and it got installed by an inexperienced person who thought it would not matter.

You two need to let it rest, please.

I don't work for mb or a dealer or anything automotive related, I just have owned about 31 old mercedes and done and had done a lot of work on them.

Have a nice weekend.

jsap,
I would not try to replace a liner in an alloy block. Even if the OEM had the liner available, The likely hood of a replaced straight liner staying in place in an alloy block is questionable. Experience with other similar applications of metal inserts in alloy shows it to lack longevity. Many applications of bearings pressed into alloy eventually need a sleeve because the hole has enlarged over time. Motor cycle motors & small stationary engines often have steel or iron liners in alloy. Some are throw away as the liner is too thin to re-bore. I dont know if the bluetech diesel motors have removable liners. If one failed maybe it would be best to replace the block. Normally when a failure like that occurs there is a hole in the block any way.

Many diesels with removable liners with the top lip are not interference fit. They allow the sleeve to float, its fixed on the flange at the head but can move up & down in the block. Examples being Gm 2 strokes & John Deere 404 cu in sixes. When the sleeve needs removal they are just tapped out with a hammer & a block of wood.

There are many small ricer type petrol motors with steel liners in alloy blocks, eg Daewoo & some Nissan. Many of these alloy blocks are high pressure cast around the liners. Over time the alloy will stretch as it has a lower yield strength than the liner & so the fit between the alloy block & the liner will not be as tight in time. I dont know if these liners are replaceable, again one could consider them throw away if the bore was so damaged that re-boring would not fix it.

If we now consider the liner of the OP's 617. These motors are a cast iron block with the liner pressed in. There is considerable interference between the outside of the liner and the hole in the block. After installation it is necessary to bore the new liner. There is little likely hood of it loosening over time as the block & liner have similar yield strength. Most who have removed liners comment on how hard they are to get out, requiring a loaded press. You may well ask then why this motor had a liner down a little? The head had been off previously. My money is on the motor previously having a slight head gasket leak. Some one has tightened down the head greatly, say a turn or 3 on the head bolts, (we have successfully tightened down a head an extra 10 or 20 ftlb to stop a slight leak). If this over tightening was done with a motor with an old hard carbonized head gasket, It could result in the liner being pushed down a little. The force would be great enough. In time when the gasket was replaced the out of place liner would be discovered. When the head was taken off no significant damage to the bore was reported suggesting that it wasnt a bore seizure that caused the liner to move down. This is only a suggestion on my part, I cant see any other explanation that fits other than an incorrectly fitted liner.
I am waiting for a thread on here about a bluetech being rebuilt. Can the liners be successfully replaced?

Your M119.98 is another story. we dont know enough about its history or have pics of the liner.


Tom, Thanks for your comment !!

Slipped liners are indeed rare. But, again, it probably happens more often than we think, as most people in high-labor-rate locations would be advised to replace the engine rather than to tear it apart for diagnosis. Such discarded engines would then go to engine recycling specialists.

I've never thought about slipped liners until now. One long-time mechanic who only does Mercedes tells me that he saw 2 in his lifetime (I think 20 or 30 years of being a mechanic, I can't quite remember).

My M119 is thought to be bulletproof, but I've read one person whose short block cracked. On mine, it overheated due to a clogged catalytic converter. The mechanic thought it was the transmission control unit, so he replaced it and said it's ok for me to continue to run the car. 200 miles later, I had another shop replace the catalytic converter, and the car ran fine from then, but then developed a combustion leak that seemed to slowly get worse. It started as a tick tick tick. It developed into a thuft thuft thuft.

I don't think anyone could advise me anything other than to replace the engine or get the liner replaced. And I would advise anyone the same. But, since this block is already shot, and since in my pre-retirement my work involved developing things that have never existed, and since my labor is free, I could try an experimental repair.

I would say, though, that if I do try any experimental repairs on this, that it would not be my intention to suggest to others to try the same. Having said that, I am open to any suggestions by anyone. It's a curious problem, and an inventive solution might exist, which I'm willing to try.

Where is it leaking to?

Because of the reduced surface area of the ring seal on the head gasket, and because it's an open deck, the leak is from the combustion chamber sideways into the coolant. And, coolant is obviously entering the cylinder (probably during engine braking), since this particular cylinder is very clean. The piston is not much cleaner, but the roof and valves are very clean, including the exhaust valves.

I've measured the surface area, and the ring seal now has 70% of the contact surface of the original. With a proper shim design and adhesive, if the liner doesn't drop any further, the ring seal should be back to 100% surface area. For all I know, with the right repair and some luck, this engine could come back from the dead. Who knows. Worth a try, since I've already sourced a replacement engine.

Coolant will also enter the combustion chamber when the engine is shut off. The residual pressure in the cooling system will push it in, then when started it will puff steam on start up and then quit.

Interestingly, despite the steam-cleaned valves, the chamber never took in enough water to blow white steam. But, as you say, there was coolant coming in when the engine was off, which I noticed through the spark plug threads. This was difficult to diagnose, however, because it was mixed with motor oil.

Another thing of interest was that when the engine was fully warmed up, all noises stopped, as if nothing was wrong. Presumably, the expanding aluminum block and head was providing enough pressure on the gasket to stop the leak and all other symptoms. This is what makes me believe that a repair might be possible.

Well, we've had several pages of a pissing match all for nothing, and we've described slipped liners over and over again. Care to put on the table any consideration that I might contemplate on my experiment?

How far has the liner slipped & how thick is the liner?
Have you had the sump off to see if the liner is protruding below the block in the sump area? It maybe possible to burr the base of the block to prevent further slippage.
A pic or 2 of the liner would be useful.

The shims put in the motor I spoke of were about 3/16" wide & between 20 & 50 thou thick.I have had a good look but cant find the old ones.
We placed a straight edge ruler across the top of the block & used feeler gauges to find the required thickness. We added 1 or 2 thou to the measured thickness so as to come up with a thickness that we could get shim steel.
The inside edge of the shim was about 20 thou in from the inner edge of the liner. The ones that came out when we took the head of were not burned at all, they had a good coating of carbon on them. Probably we could have re-used them. As we had a new head gasket, we decided to make new shims. We didnt use any loctite or other glue. The motor has done about 2,000 hrs on a pump since without any problems.

The M119 engine has a free standing sleeve with coolant all around it? It is secured only at the bottom?

And you have had the head off to verify all this?

Tom,
I have no idea, the owner will need to tell us. If it has wet liners as you ask, then I wouldnt think they could slip.
I think we need to see some pics before going any further.
I have assumed that the motor has dry liners in an alloy block with a complete surface on the top of the block, like a 617 but alloy instead of CI.

Edit,
I have been doing a bit of looking. The second gen M119 has wet liners, I cant see how one would slip, they look as though they are pushed into the bottom of the block from above. They are sandwiched between the bottom of the block & the head. They are a very exotic alloy as was mentioned earlier. You cant just re-bore them in a conventional way. The pistons are iron coated aluminum (you think 617 pistons are expensive!!!).

Sorry gents for the delay. I wanted to get you a picture plus accurate measurements.

http://img508.imageshack.us/img508/9915/img5848.jpg

I measured it with a digital caliper with 0.001 accuracy.

The liner is about 0.11" thick, but the gasket sitting on top only touches about 0.07". Still, I think I'd fabricate the shim the full 0.11".

The slip depth is about 0.072"

No, I've not taken the sump off. It didn't seem to matter whether there's a stop or not. Half the machinists I've spoken to believe it won't slip any further. And one very experienced Ford machinist who races believes that wicking Loctite 290 will help to secure the liner. (Also, I don't want to drain the oil now, because when I run the engine to operating temp after installing the new gasket, there will be a bit of coolant contamination in the oil because the water jacket doesn't swell until initial warm up.)

I believe that it's a dry liner. I don't see any holes around the cylinder wall, and an aftermarket liner catalog lists it as dry. It's an open deck, if that's what you were thinking.

I believe it's secured simply by interference (friction).

Again, as to whether there's a tab or lip at the bottom, it's sort of trivial to me at this point, because I'm going to try this experimental shim repair method by hook or crook. But, the next time I remove the sump, I'll have to take a look for future reference.

All M119's were closed decks. But the last M119.98x series were open decks, but still dry. I think that's what you were thinking?

Edit: My current plan is to use Loctite 290 wicked into existing liner. I'll fabricate a ring with the dimensions above, but with the OD 0.004" smaller to allow easy fit and gap fill with Loctite 640. I'll use the 640 on both the outside and bottom of the ring to adhere it to both the exposed cylinder wall and the top of the liner.

Wow. I have never seen anything quite like that.

Based on my experience with mb diesels I would expect a lip at the bottom to stop it from slipping. If it had that, at this point, it would have to be broken off and in pieces in the sump.

I feel that I must apologize. By right, I should have warned you to put your wife and kids to bed before you view this image. Now, I am afraid that I have exposed your innocent wife and children to the cruelties of this world before they are ready.

Oh, btw, I dropped my lower sump recently before I pulled the head, and there's no metal pieces down there. I haven't dropped the upper sump, however.

Given everything is aluminum alloy, I would be making the ring from duralium or some similar aluminum alloy. Using a steel ring may cause some galvanic problems.
That is a very good & informative pic of the problem. I have a theory on what caused it but I want to run it past a couple of colleagues first. Have you owned the car from new?
I have no experience with the loctite product you mention.
I would be checking the block & head for flatness.