MD11c cylinder jacket question

[kellys]

I recently had both heads off my MD11c. When the engine is running I have noticed weeping along the base of the front cylinder on the oil dipstick side of the engine. Looking at the schematics the 3 o-rings near by are for the oil feed tube to the rockers and the 2 push rods. The only water near by is in the cylinder jacket I think. I have rechecked the head torque and it´s OK. Can anyone let me know does the cylinder sleeve in the jacket act as part of the walls for cooling water flow or does the jacket itself have its own water passages. I have not seen what the water jacket looks like without the sleeve installed. If the sleeve is used as a water barrier then water could be running down the outside of the sleeve to the top of the block and cylinder jacket base. Can I just keep a watchful eye on this? Any comments on fixes are most welcome.

 

[VicS]

Yes they are wet liners.

There are O rings between the liners and the blocks. 1 under the collar at the top and two at the bottom.

see page 27 of the workshop manual

 

[VicS]

part #21 is the kit of O rings

 

[kellys]

Yes they are wet liners.

There are O rings between the liners and the blocks. 1 under the collar at the top and two at the bottom.

see page 27 of the workshop manual

Hi Vic,
Thanks for the reply.
Should the o-rings prevent water from seeping between the block and bottom of water jacket as is the problem I have?

shane

 

[VicS]

Hi Vic,
Thanks for the reply.
Should the o-rings prevent water from seeping between the block and bottom of water jacket as is the problem I have?

shane

Its along time since we had one of these in pieces ( even then we did not remove the liners)

Those O rings should seal the water into the cooling jacket

I guess you must have a slight leak in the front one. There are no joint gaskets between the cylinder blocks and the crankcase, only the spacer shims so if the bottom O rings leak water will appear where you are seeing it.

BUT water could be running down from the cylinder head gasket or even the exhaust manifold gasket. There are also core plugs in the heads that could leak.

 

[Bilgediver]

Hi Vic,
Thanks for the reply.
Should the o-rings prevent water from seeping between the block and bottom of water jacket as is the problem I have?

shane

I would have thought that any water leaking from the liner to block seal would drain into the sump????? Is the sump oil discoloured???

 

[VicS]

I would have thought that any water leaking from the liner to block seal would drain into the sump????? Is the sump oil discoloured???

No because there is another O ring between the protruding section of liner and the crankcase.
#38 in this diagram

 

[kellys]

Its along time since we had one of these in pieces ( even then we did not remove the liners)

Those O rings should seal the water into the cooling jacket

I guess you must have a slight leak in the front one. There are no joint gaskets between the cylinder blocks and the crankcase, only the spacer shims so if the bottom O rings leak water will appear where you are seeing it.

BUT water could be running down from the cylinder head gasket or even the exhaust manifold gasket. There are also core plugs in the heads that could leak.

Hi again Vic,
I have looked at the other leaks sources as you mentioned and found nothing, I will double check again before tearing down (next winter). The other poster mentioned about discolored sump oil, it's fine. I have recently had the heads off due to a cracked injector sleeve on the rear cylinder, this was a good opportunity to clean the cooling passages, I stopped short of removing the cylinders as I had to draw the line somewhere. For now I will keep an eye on the leak and sump oil for changes. Next tear down I will pull the cylinders and sleeves and replace the seals, or maybe new liner kit,rings and pistons...
anyway thanks for the help.

regards,
Shane

 

[Bilgediver]

No because there is another O ring between the protruding section of liner and the crankcase.
#38 in this diagram

Canny Volvo......


Mind you not so canny in one other aspect. Maybe when the OP draws the liners to replace the O rings he could report on what he finds on the liners opposite the drain cocks. I have seen a strange effect where it looks like someone has tried to drill a hole . In fact in one of the editions of PBO this was visible in an overhaul artical but no mention made of it.

Maybe the liners could be re inserted to a different orientation and so extend their life if not badly worn in the bores.

 

[VicS]

Canny Volvo......


Mind you not so canny in one other aspect. Maybe when the OP draws the liners to replace the O rings he could report on what he finds on the liners opposite the drain cocks. I have seen a strange effect where it looks like someone has tried to drill a hole . In fact in one of the editions of PBO this was visible in an overhaul artical but no mention made of it.

Maybe the liners could be re inserted to a different orientation and so extend their life if not badly worn in the bores.

No 1st hand knowledge/experience of this but I believe the liners can become perforated adjacent to the position of the block drain cocks due to galvanic action.
It's low down so not visible when just the heads are removed but can lead to water getting into in the crankcase.

OTOH I may just be repeating something you have posted in the past.