volvo md11 sudden stop - puzzled as to why?

PaulR

PaulR

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delivery trip for friend - ran md11 at c2000 revs - sounded fine and cooling water running from exhaust but with n o warning and no faltering after about 30 minutes engine suddenly stopped .

Checked and found prop shaft rotating ok , fuel visible in prefilter bowl looking good and oil level fine BUT some smoke coming from outside of engine when we opened engine box and engine rocker covers very hot to touch .

Let engine cool for a few minutes then it restarted fine and ran fine albeit we only ran it very gently for a few minutes and then sailed for c 6+ hours before starting it again to motor into destination harbour.

Owner confirmed that he might have spilt some oily bilge water on engine as he had mopped out build up of oily bilgewater from underneath engine - I wondered if that might account for the smokey fumes found when it had stopped suddenly.

Cooling water running throughout as visible and audible in exhaust outlet but remain puzzled as to what might have caused sudden stoppage without any pre stop faltering.

My current thoughts are could it have been a blockage in fuel supply (last filled up years before and has been out of water untouched for c 2 years ) but if that was it why no faltering before stopping and why would fuel be visible in glass prefilter bowl and why would it then a few minutes later start fine

OR

was engine overheating and if so would or could that lead to sudden stoppage and once it had cooled down a bit allow it to restart and run under lower throttle setting without issue?

Were it my engine I would be inclined to either drain and replace fuel and use a treatment incase any bug issue from long period left untouched and freshwater flush raw water cooling ciircuit and potentially using scale remover in case of muck build up in cooling passages to try and ensure they are clear and ok .

What do you think might have caused sudden stop?
 
I would suggest that the engine had seized due to overheating. The immediate symptoms suggest that the thermostat may have failed closed or the waterways in the block were furred up with salt or corrosion. If the particular engine is fitted with a heat exchanger for FW cooling (I'm not aware that any MD11's were) it may be that the engine pump has failed. Either failure (thermostat or pump) water would not be circulated through the block and thus cool the engine. These old diesels are pretty robust brutes and a temporary engine seizing is unlikely to cause much damage beyond a broken ring and perhaps a scored cylinder.
 
If fuel is okay I would suspect overheating too and agree with Topcat's comments. (Also I would have expected a fuel issue to cause a drop in revs before cutting out out)

Does it have working temperature gauge and oil pressure light?
 
PaulR said:
........Checked and found prop shaft rotating ok , fuel visible in prefilter bowl looking good and oil level fine BUT some smoke coming from outside of engine when we opened engine box and engine rocker covers very hot to touch .

Let engine cool for a few minutes then it restarted fine and ran fine albeit we only ran it very gently for a few minutes
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If you suspected overheating I think that was a mistake. You should have waited much longer.
 
penberth3 said:
If you suspected overheating I think that was a mistake. You should have waited much longer.
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perhaps but at time didn't immediately suspect overheating - my first thought was something caught on prop and stalled it but as mentioned we checked prop shaft was free to rotate so ruled that out - it stopped running when we were within a few 100 metres of passing through the passage through the submerged obstruction running from southsea shore to the forts so had to focus on getting sails up and sailing through the passage - having done that then in safer water so then checked oil and fuel and tried to restart - if it had not started would have had to decide promptly whether to abandon trip and sail back to gosport or carry on and attempt to sail into destination port (if wind remained) - not keen on that as destination port requires passing through a lock to the none tidal basin - not easy without engine and was , if wind remained, c 7 hours sailing away.

Luckily it did restart and we then shut it down again and sailed until about to enter our destination port.
 
What does very hot to the touch mean? If you can keep touching and it not be painful it will be under 50C and of no consequence, if you can touch momentarily without burning 60-70C. I would expect a seizure through overheat to be much hotter, with a lot of smoking from oil/fuel leaks evaporating as smoke and possibly peeling and scorched paint. Without checking that the flywheel was free to turn when it stopped it's impossible to say, although seizure does seem the most likely explanation.
 
Topcat47 said:
I would suggest that the engine had seized due to overheating. The immediate symptoms suggest that the thermostat may have failed closed or the waterways in the block were furred up with salt or corrosion. If the particular engine is fitted with a heat exchanger for FW cooling (I'm not aware that any MD11's were) it may be that the engine pump has failed. Either failure (thermostat or pump) water would not be circulated through the block and thus cool the engine. These old diesels are pretty robust brutes and a temporary engine seizing is unlikely to cause much damage beyond a broken ring and perhaps a scored cylinder.
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That's exactly what happened with our MD11C, overheated and seized. After a while cooling down would start again and if run hard, would seize again. Turned out mainly to be blocked cylinder heads and manifold passages but when I pressed the liners out, a fair amount of crud in the water jacket as well.
 
Graham376 said:
That's exactly what happened with our MD11C, overheated and seized. After a while cooling down would start again and if run hard, would seize again. Turned out mainly to be blocked cylinder heads and manifold passages but when I pressed the liners out, a fair amount of crud in the water jacket as well.
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thanks Graham does sound like it could be overheating issue - will have a go at it with friend whose boat it is - re post earlier didn't think to try and turn flywheel by hand as at time thought most likely issue was either prop wrap or fuel problem - in terms of how hot it was too hot for my hands but I am first to yell with hot plates which wife can hold bare handed so may be wimpish! Was able to undo and remove screw in dipstick by hand and check oil level and no fumes coming from dipstick hole or off oil on dipstick.
 
If the engine has stopped due to overheating, undoubtedly it had sustained permanent damage to the bearings and perhaps to other moving parts, however, these engines are very robust and may not notice any difference. Of course the engine will start again when cooled down. One of the main causes of overheating of the Volvo MD11 is the cylinder head water channels has been blocked with calcium.
Removing the calcium is an easy job; just recycle any lime removal chemical, (the easiest way is to pour in the chemical through the temperature sensor on top of the manifold). Many owners of these engines remove the water thermostat altogether, which is not the best solution. I had a boat with an original 48 year old MD11C which run perfectly well and always on superior fully synthetic oil of the correct viscosity with annual oil filter changes.
 
PaulR said:
thanks Graham does sound like it could be overheating issue - will have a go at it with friend whose boat it is - re post earlier didn't think to try and turn flywheel by hand as at time thought most likely issue was either prop wrap or fuel problem - in terms of how hot it was too hot for my hands but I am first to yell with hot plates which wife can hold bare handed so may be wimpish! Was able to undo and remove screw in dipstick by hand and check oil level and no fumes coming from dipstick hole or off oil on dipstick.
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As you say "could be overheating" so check everything else out before stripping. It's close on 30 years since I rebuilt mine and parts were expensive then so, would suggest a new engine may be a better option these days if needing new pistons, liners and bearings. Old engine will still have old gearbox with cone clutch which will pack up at some stage.
 
did some checks om it yesterday with owner-thermostat removed and checked in hot water and opened fine-undid the drains on side of block and both ran freely and flushed them out as precaution- flushed engine with freshwater and ran under load for 20 plus minutes - temp gauge not working fully - need to check sender next time - oil warning light not working (battery working light fine), next steps check exhaust elbow and impeller then plan to run descaler through in closed loop in case any issues and use infra red thermometer to check temps when running -also plan to sort temp gauge and oil light - thanks for guidance so far
 
CAPTAIN FANTASTIC said:
If the engine has stopped due to overheating, undoubtedly it had sustained permanent damage to the bearings and perhaps to other moving parts, however, these engines are very robust and may not notice any difference. Of course the engine will start again when cooled down. One of the main causes of overheating of the Volvo MD11 is the cylinder head water channels has been blocked with calcium.
Removing the calcium is an easy job; just recycle any lime removal chemical, (the easiest way is to pour in the chemical through the temperature sensor on top of the manifold). Many owners of these engines remove the water thermostat altogether, which is not the best solution. I had a boat with an original 48 year old MD11C which run perfectly well and always on superior fully synthetic oil of the correct viscosity with annual oil filter changes.
Click to expand...

Apologies for opening this old thread........I'm looking to solve a similar over heating issue with my MD11C, you say that removing the calcium is an easy job? Can you help me and provide me with some simple pointers?
 
Use of a descaling liquid(Rydlyme is often cited, although many make their own using various acids) is pretty straightforward, just follow the instructions.
 
If the engine has not been descaled before, I suggest that you remove the exhaust manifold, ( easy job) and soak it in a descaling acid, there are many around, I use "Domestos Zero Limescale" (Tescos £1.50). Now that the exhaust manifold has been removed, you can clean all the waterways on the cylinder head, it is likely to be blocked solid so use a piece of wire or other means to clear the waterways. Being a raw water cooled engine, there will always be calcium deposits, therefore, recycling a descaling acid periodically is necessary. I found the best way is to pour the descaling through the temperature sensor. Good luck.
 
Re Captain Fantastic

I also have a raw water cooled MD11C. How exactly do you carry out your process?
Do you let it sit for a while or immediately run the engine and what happens to any
dislodged deposits?
 
The acid dissolves the soluble calcium deposits, and carried away through the exhaust mixed with the raw water. I used to leave the acid in the engine for an hour and then start the engine to flash it out, or when the boat was in the yard, I was operating the engine and recycling the diluted acid for an hour.
 
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