pushed in cylinder sleeve, how long till another blown head gasket?
 

Short version:

#4 sleeve on a 260,000 mile OMM617.951 is pushed 14 thousandths too far into the block. It has been this way for at least 3,500 miles but eventually an unfortunate major overheating caused the head gasket to blow around it. Milling the head down would leave the piston overlap at .042", which is 7 thousandths over the MB tolerance. Options are:

A: Replace head gasket for an additional $590 and hope it lasts for a long time.

B: New engine for around $1000 (seems the best to me, although there are some ifs involved)

C: Mill down block as much as possible and cut the gap to 7 thousandths and new head gasket. Don't know how much this would cost.

What do you guys think?

Longer Version:

I have a 1984 300SD with 260,000 miles. Not that long ago I was driving it and the engine temperature gauge stopped working. I didn't thing too much of it but a few hundred miles later the thermostat stuck and it started overheating. I didn't know this was happening till the coolant hose broke and it started smelling like burning coolant in the car. long story short, massively overheated and the head gasket ended up blown.

I took it to a shop and they tore into it. They discovered a relatively new head gasket, although how new he wasn't sure. I had put at least 3,500 mile on it is all I know. They also discovered that the #4 piston sleeve was pushed in to the block 0.014" too far. Apparently in a past life this sleeve had been installed incorrectly, or somehow pushed in by something else. My mechanic and I couldn't really figure out how that could have happened. Getting the top resurfaced down 14 thousandths so that the sleeve is flush again will put the piston overlap 7 thousandths over MB's specified range of acceptable values so that isn't really an option. I'm $300 into the head gasket replacement already. My options are below:

1: continue with the head gasket for another $590 and hope for the best. Who knows how long it would last without overheating the engine again?

2: I may have a line on another engine for $1100 with 100,000 miles less on it then mine. I could then possibly sell my current engine's turbo and manifold locally for at least $300 and install the new engine. This seems like my best option, and I may be able to find someone who could help me install it myself thereby saving shop time. This seems like the best option

3: Mill the block down 7 thousandths for who knows how much more money and do #1

Anyone have any experience with this? What do you think I should do?

Is it not possible to pull and replace the sleeve? Just a thought...

Have you given any thought to replacing the liner on that cylinder?

HAHA - beat you to it! ;)

What you are describing will require pulling the motor anyway, so the only logical thing is to replace the sleeve and mill it flush as it was supposed to be in the first place.

I don't know how you would do this without working at it.

The ring is cut on the bottom of the bore at the factory to stop the sleeve from going too deep and the sleeves are a little too long so you have to push them in and then deck the block so they are all exactly flush with the block.

It is probably cheaper to buy a used motor but this one should have all new parts in it right? If so it should be worth fixing. The person who put in the sleeve wrong should be paying for the fix.

Good luck.

Tom W

Betcha I know how. They probably didn't get it pressed all the way to the bottom of the bore (like maybe it needed to go in another .0014") and then they decked it. Then over time and due to compression, friction, heat, etc. it finally dropped that last .0014" on its own....

That sounds possible but....

I don't see how the sleeve could walk down the bore.

Maybe someone can say if thats possible or not.

Tom W

Yeah, the car has an interesting past. As far as I know it was driven by one owner in Texas for almost all of those miles then traded against an outstanding debt to a guy here in Montana, where it sat for a few years before making it to me. I wonder if it's worth trying to figure out who installed the cylinder sleeves?

I guess this means it was rebuilt, which would have been good news to me if not for the other thing. . .

Seems unlikely that it would slip down, but maybe the extreme temperatures of me overheating it and a CTE mismatch allowed this to happen? Can't really come up with any other explanation except for the sleeve being way too short in the first place.

couldn't you try to freeze the sleeve with liquid nitrogen to shrink it then try to pull it up to place. Its worth a try if you are going to have to rebuild it anyways. Just make sure the piston is at BDC and then pore the liquid nitrogen in, the sleeve should shrink and you should be able to move it. If the shrinks to much and gets stuck to the piston then turn the engine and the sleeve should move up. This sounds like a possible solution. I am not 100% sure whether it will work but its at least worth a shot.

for my money, I'd put in a new sleeve, and have it correctly pressed in all the way to the stop, and properly milled flush with the deck.

yep.

And while its apart I would have the clearance on the bearings checked. It sounds as if it was built by someone who didn't know what they're doing.

If the work was done before you got the car you will probably have a tough time collecting anything from the offending party, no matter how right that might be.

Tom W

Yes you did. And I agree with you idea.

Always a good feeling when you float an idea and someone who knows more than you seconds it :thumbup:

replace head gasket for an additional $590 and hope it lasts for a long time.

Uh... 590$?!> what is it made out of spotted owl?

Shop labor. I didn't have the time, space, equipment or knowledge to do it myself. I don't have any money either now that I think about it. . . .

Getting a new sleeve installed and milled would cost a lot more then the replacement engine and installation.