Assessing an old engine (Volvo MD11c),servicing advice,Emsworth/Shoreham.

[FairweatherDave]

We've had our Centaur for two seasons now and the trusty engine has never let us down yet. So twice I have done the basic servicing/winterising (boat is out the water Nov-March). We don't use the engine much....... maybe 20 hours a year. We don't push the engine hard, as long as we are travelling around/just over 4 knots I'm happy. Should I carry on with just doing my annual service, looking and listening for any changes/problems and being prepared or should I get someone to look at it. Presumably to look at it they would want to see the boat in the water rather than running a hose pipe into a bucket for the water intake. And would they want to look at the boat out on its swinging mooring or expect me to bring it to them wherever. What tests might they do? Obviously those tests don't guaruntee the engine won't conk out from some other cause. Boat is in Emsworth until I bring her round to Shoreham for the winter lay up. I know there are plenty of boat services around Emsworth but recommendations here (maybe by private message) might be good.But also should I be doing it at all given the engine has been running fine under my minimal care for two years? The engine before I bought it had been rebuilt, well looked after but is the original MD11C. Sorry these are some basic questions and don't have simple answers but some opinions and recommendations here would be really appreciated. Regarding my level of expertise I am no mechanic but have done the RYA Diesel maintenance course but know my limits and respect the pros.

 

[pvb]

If it starts and runs well, what on earth would you gain from paying a professional to look at it? As you said yourself "Obviously those tests don't guaruntee the engine won't conk out from some other cause." Keep doing the annual service and winterising, keep an ear out for any changes in engine note perhaps, otherwise just enjoy your boat.

 

[TQA]

If it starts reasonably easily from cold.

If it does not smoke excessively under load, some smoke is OK but not smokescreen stuff.

If it does not need the oil topping up at more than a pint every 3 -4 hours use.

If the oil pressure does not drop when hot and the revs are 1500 +.

You can reasonably expect many many more years of service at 20 hours pa.

I am in the same position. My old lady has a Japanese built Perkins 154 35 years old. Starts and runs fine. Just the usual rear crankshaft oil seal leak. I am hoping it sees me out as re-engining with something different is a big and expensive job.

 

[FairweatherDave]

Thanks both for the reassurance. It starts beautifully and I don't regard it as smoky and it does not use oil in any significant quantity. The engine temp dial does not function so I test the exhaust water by hand which I was taught by the guy who taught the engine maintenance course, it never gets too hot while I count slowly to three which I'm told is therefore fine. The revs I simply judge by ear and aiming not to exceed 5 knots. I've never seen the oil pressure lamp come on except during the starting procedure. I'll keep on with my current gentle use, basic maintenance and keep monitoring what I can. Let's hope I haven't tempted fate here....
PS I have read the view that diesels like to be exercised properly (pushed) but I think that might be truer of younger less vulnerable engines.
I will carry on and "enjoy the boat".

 

[VicS]

Thanks both for the reassurance. It starts beautifully and I don't regard it as smoky and it does not use oil in any significant quantity. The engine temp dial does not function so I test the exhaust water by hand which I was taught by the guy who taught the engine maintenance course, it never gets too hot while I count slowly to three which I'm told is therefore fine. The revs I simply judge by ear and aiming not to exceed 5 knots. I've never seen the oil pressure lamp come on except during the starting procedure. I'll keep on with my current gentle use, basic maintenance and keep monitoring what I can. Let's hope I haven't tempted fate here....
PS I have read the view that diesels like to be exercised properly (pushed) but I think that might be truer of younger less vulnerable engines.

I would, if I were you, try to get the engine temperature gauge working.

The temperature of the water coming out of the exhaust is no indication of the engine temperature.
If it rises it'll be due to a drop in flow rate due to obstruction or pump impeller wear.

The gauge is what will tell you about the engine temperature. That can rise due to drop in flow though just the engine while the flow of water leaving the exhaust remains little affected.

Even the engine temperature gauge is not infallible because with the design of that engine it is possible for one cylinder to be overheating while the other over cools.
A good idea therefore to feel the cylinder heads, but they are, or should be, too hot to maintain finger contact more than briefly.

 

[Tranona]

PS I have read the view that diesels like to be exercised properly (pushed) but I think that might be truer of younger less vulnerable engines.

Just as relevant with your engine as any other small diesel. Running it hard from time to time helps with two common issues - not reaching full temperature and coking up the exhaust at the mixing elbow. aim to run it at about 70% full revs which should give you around 5 knots cruising speed with occasional bursts of full revs. You are not doing it any favours running slowly for long periods, only using marginally less fuel and increasing your passage times by 20%.

 

[DaveS]

I would, if I were you, try to get the engine temperature gauge working.

The temperature of the water coming out of the exhaust is no indication of the engine temperature.
If it rises it'll be due to a drop in flow rate due to obstruction or pump impeller wear.

The gauge is what will tell you about the engine temperature. That can rise due to drop in flow though just the engine while the flow of water leaving the exhaust remains little affected.

Even the engine temperature gauge is not infallible because with the design of that engine it is possible for one cylinder to be overheating while the other over cools.
A good idea therefore to feel the cylinder heads, but they are, or should be, too hot to maintain finger contact more than briefly.

I would agree with all of that, and would just add that some boats (like mine) only have an engine over-temperature alarm, no gauge. I use an infra-red thermometer (very cheap off Ebay) to "scan" the engine every now and again: the head and much of the block of my raw water cooled VP2002 shows a temperature of around 55°C which seems about right.

 

[cryan]

I would agree with all of that, and would just add that some boats (like mine) only have an engine over-temperature alarm, no gauge. I use an infra-red thermometer (very cheap off Ebay) to "scan" the engine every now and again: the head and much of the block of my raw water cooled VP2002 shows a temperature of around 55°C which seems about right.

This is what I would do, get yourself a laser pointing thermometer. There easily available for well under £100 these days and it will let you build up a picture of whats going on. Get a magic marker and draw a big spot before and after each cooler, before the seawater pump and somwhere on the cylinder head. Make these your monitor points and keep a log (even just in your head) of whats normal. Then with with the laser thermo you will be able to know whats happening and where its happening quickly. Pay attention to things like the temperature difference across coolers on both sea and fresh water sides as well as sea water ambient temps. That way you can diagnose heating problems as either a blocked cooler or a change in ambient or drop in flow etc etc. try to avoid using your hands to feel for things and if you do use the back of your hand. Your nose is often the best measure of overheating. (By which I mean sense of smell and not sticking your beak on hot pipes!) The real skill in machinery watchkeeping is getting to know whats normal first.

As for paying a pro to do your routine checks? If you based in Scotland, specifically the east coast then yes you should get a pro in and I recommend CRYCO Ltd of Kirkcaldy. However if your on the south coast then I would say just keep on doing what your doing unless you have a real concern.

 

[FairweatherDave]

I would agree with all of that, and would just add that some boats (like mine) only have an engine over-temperature alarm, no gauge. I use an infra-red thermometer (very cheap off Ebay) to "scan" the engine every now and again: the head and much of the block of my raw water cooled VP2002 shows a temperature of around 55°C which seems about right.

This is making me think how to get the temp guage to work. Unfortunately my Nigel Calder books are on the boat. It is easy enough to buy a IR thermometer as a stop gap measure (like that idea) and a double measure of engine temp if the gauge was working, but how easy is it to fix or replace the temp gauge. Presumably you electrically test the gauge and connections (most likely source of problem) then replace the sender unit if still no go. Once I had a functioning temp gauge I would be much happier pressing the engine harder. Truth is this is the limit of my comfort zone and shows why I needed to pose my original question. Is it a job better fixed while laid up on the hard or better with engine able to run easily in the water.

 

[FairweatherDave]

Sorry Cryan, will read your post after supper while head remains on my shoulders

 

[VicS]

This is what I would do, get yourself a laser pointing thermometer. There easily available for well under £100 these days and it will let you build up a picture of whats going on. Get a magic marker and draw a big spot before and after each cooler, before the seawater pump and somwhere on the cylinder head. Make these your monitor points and keep a log (even just in your head) of whats normal. Then with with the laser thermo you will be able to know whats happening and where its happening quickly. Pay attention to things like the temperature difference across coolers on both sea and fresh water sides as well as sea water ambient temps. That way you can diagnose heating problems as either a blocked cooler or a change in ambient or drop in flow etc etc. try to avoid using your hands to feel for things and if you do use the back of your hand. Your nose is often the best measure of overheating. (By which I mean sense of smell and not sticking your beak on hot pipes!) The real skill in machinery watchkeeping is getting to know whats normal first.

As for paying a pro to do your routine checks? If you based in Scotland, specifically the east coast then yes you should get a pro in and I recommend CRYCO Ltd of Kirkcaldy. However if your on the south coast then I would say just keep on doing what your doing unless you have a real concern.

Is it indirectly cooled then ?..... The OP did not suggest it was.

 

[cryan]

Is it indirectly cooled then ?..... The OP did not suggest it was.

No your right its directly cooled by sea water(I had only read volvo penta and not MD11) HOWEVER, Marking temperature sample points and using a laser thermometer on the same spots every time will still give the OP a much better awareness of whats going on. Ok it might be a cooling channel that is becoming blocked as opposed to a tube nest in a cooler but the symptoms are the same as are the causes and to an extent the remedies. Measure the SW ambient then the in and out as well as the block, head and exhaust. Will give him a historical record so as changes become noticeable and traceable. His nose will also tell him if its too hot. Hot lub oil smells sickly sweet and treacley. Past that hot paint smells dry and dusty. And using the back of his hand and not the front will same him a nasty injury as the body naturally pulls the hand away.
So yeah there are no coolers as such but all the advice is still relevant and, in my eyes, helpfull. But people can take it or leave it as they see fit.

 

[pvb]

Isn't life too short to spend it with your head in the engine compartment, pointing a laser thermometer at marks on the engine??

I'd just fix the temperature gauge and get on with enjoying the boat.

 

[FairweatherDave]

(Mmmm good supper......head still on shoulders)
Thanks both for the further input, it really is appreciated. The IR thermometers seem to go for a tenner on e bay. Any clues on how to sort the temp gauge, (and where best, afloat or laid up)? Cheers Dave

 

[VicS]

(Mmmm good supper......head still on shoulders)
Thanks both for the further input, it really is appreciated. The IR thermometers seem to go for a tenner on e bay. Any clues on how to sort the temp gauge, (and where best, afloat or laid up)? Cheers Dave

You can do the basic checks and repair afloat or ashore but the final test will require you to either be afloat or have a decent temporary cooling water system rigged up so that you can run it until it gets up to normal working temperature...... I guess you rig something up anyway for the end of season flush out and winterisation.

Obviously check all the wiring and connections to gauge and sensor.

Check continuity of sensor.. but I dont know what sort of resistance to expect. Few tens of ohms maybe ... dunno .

??? switch on and short sensor to earth . see if the gauge responds. ???

 

[pvb]

Obviously check all the wiring and connections to gauge and sensor.

Check continuity of sensor.. but I dont know what sort of resistance to expect. Few tens of ohms maybe ... dunno .

Agree, start by checking continuity of wiring. Temp sensors usually decrease in resistance as they get hot, so shorting the sensor wire to earth ought to cause the gauge to go to the high temperature end of the scale.

 

[FairweatherDave]

Mastering some basic electrics is my challenge for the winter I think. Last winter it was the headlining priority. Nothing I like less than bobbing about on a mooring trying to decipher Nigel Calder and working out how to use my multi-meter, or sticking my head in the engine compartment, particularly if I could be sailing. I know it is second nature to some but sadly for me it is a challenge .... but I will get there. The realities of a swinging mooring and not enough time

 

[VicS]

Mastering some basic electrics is my challenge for the winter I think. Last winter it was the headlining priority. Nothing I like less than bobbing about on a mooring trying to decipher Nigel Calder and working out how to use my multi-meter, or sticking my head in the engine compartment, particularly if I could be sailing. I know it is second nature to some but sadly for me it is a challenge .... but I will get there. The realities of a swinging mooring and not enough time

If you are such a novice with electrics as you claim the "Boat Electrical Notes" on Tony Brooks' TB-training website may be useful http://www.tb-training.co.uk/

 

[Barleycorn]

Back to the OP you could get the oil analysed to check for any bearing wear etc. I was offered this on a boat that I am currently buying. Yacht surveyors should be able to organise it.

 

[pvb]

Back to the OP you could get the oil analysed to check for any bearing wear etc.

Isn't it almost certain that an MD11C will have bearing wear?