Boat Fault Finding - Marine Engine Problems

I must assume that you have had the crank journals reground AND the correct undersize bearing shells have been fitted. If you have a ground crank and standard bearings, this would give these symptoms plus noise.

When I get these symptoms on Listers I first think about oil dilution from internal fuel leaks. Is the sump level going up? Can you smell diesel in the oil? Is the oil getting thin and runny. If you answer yes to any of these, the change the oil and find the where the fuel is leaking inside the engine case.

From memory, the Lister uses a shim adjusted oil pressure relief valve. Did you check the maximum oil pressure against the Lister spec. after the rebuild? Do not adjust simply to get a higher pressure, it MUST be set as per the Lister data.

After you have checked all the above, I would suspect a worn oil pump, but that 1.5 hours before the pressure starts to drop seems a bit long to me, hence my feeling its oil dilution.

IF you are talking 10psi on idle, that may be correct as long as you have 30 to 40 psi under normal running.

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What an absolutely great way of telling customers how to do this job - assuming you can get at the marks!

This is far easier, but a little more time consuming.
Turn the engine until one valve is fully open (as far down as it goes).
Mark the lower, front engine pulley or the flywheel - which ever is easiest with a bit of chalk.
Turn the engine one complete turn until the chalk mark is very approximately back where it started.
Adjust valve clearance on that valve.
Mark rocker to show that you have done it.
Run chalk mark off pulley/flywheel.
Repeat for all other valves.

This works for any engine with any number of cylinders.

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With such scant information I have very little to go on, but first you must be sure that your revcounter is not telling lies - you will need to borrow/hire/buy a mechanical gauge to push against the front pulley or flywheel nut.

Let us first assume that this is a new "problem" and it has only just appeared.

Is there a small air leak into the suction side of the fuel system - check all unions.
Is the "pick up" supply pipe in the fuel tank partially blocked - these should have a gauze strainer on the end and may deed checking.
Is the fuel lift pump worn and supplying insufficient fuel for maximum speed.
Does the engine have an adequate air supply and are any air filters squeaky clean? Is anything obstructing the air supply to te engine like soundproofing with no vents?
Is your exhaust hose hose delaminating and forming a partial blockage when you pass large volumes of gas down the pipe? This can happen after a raw water supply failure (blocked sea inlet).
Is the silencer causing back pressure? Is the engine old enough to have built up carbon on the back of the valves so the inlet or exhaust ports are partially blocked?
Is the injector pump(s) correctly timed and adjusted (maybe someone has altered the maximum speed stop - but I would be very wary in adjusting this in case the problem is else where)?

The list is endless and just goes on.

In reality as long as the boat is performing adequately, starting easily and does not produce excess exhaust smoke I suspect you may well spend time and money chasing something of little consequence.

If you want to do some tests:-
Remove the lift pump outlet pipe and check the pump delivery against Yanmar's spec.
Remove the exhaust hose from the mixing elbow on a warm engine and then test the maximum speed out of gear. If this makes on difference put it back and assume the exhaust is OK.
Remove the air cleaner(s) and try the maximum speed again. If this engine has one cleaner per cylinder you may be able to see the back of the inlet valves through the port, otherwise you would have to remove the inlet and exhaust manifold to try to look/feel through the ports to check the back of the valves for carbon.
I suspect having the injectors and pump(s) checked would produce little improvement and will cost money, but this would be the next step. Although I can not see the difference in oil viscosity causing this I would change the oil before spending much money.

If this is not a new problem it could be too small diameter exhaust hose, Too small fuel pipes, badly adjusted injector pump and so on.

I would not be so worried about the maximum speed in gear because propellers are often not quiet perfect for the boat, and hull fouling can also affect the result (as can running it tied up and in gear).

The other thing about the "in gear" speed is to remember that you should have two maximum speeds - the continuous one and the emergency one.

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I am a bit concerned that it is always number 4 that fails and wonder if anything is causing that cylinder to burn hot, however I have no idea what it could be. I suspect the plugs are getting very expensive, so something has to be done.

First use a voltmeter to check that the plugs are indeed NOT supplied with current when the engine is running and the ignition switch in the "run" position. Voltmeter at 20 volts between live terminal and the block - expected result about zero.

It might also be worth measuring the resistance of the other plugs just on the off chance that one has a lower resistance than the rest, or even fitting a whole new set.

I am afraid that converting to "modern" 12v plugs would require threaded bushes to be made. The body of an old plug would give the outside profile and thread, whilst the new, 12v, plug would give internal thread and shape. Some care must be taken to ensure that the new plug does not foul the far side of the pre-combustion chamber. If you have access to a lathe or a friend in engineering this may be a sensible option. I have no knowledge of commercially available converter bushes, but it might be worth talking to ASAP Supplies.

As far as Easystart is concerned, the problem is that it can "fire" well before the correct time causing a massive pressure rise in the cylinder, this can then snap piston rings and even the piston itself. Sparing and careful use, strictly in accordance with the instructions for a diesel engine should be OK, but the margin for error is small and I would be unhappy with this as a long term solution.

I know that the 1.5 head fits the 1.8, so there is an outside chance that the 2.5 head will fit the 2.2, if this is the case it is designed for the 12v plugs and may well be the easiest way to go. Talk to ASAP and Calcutt boats to try to get a lead on this.

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For any engine I must advise that you check the mariniser's manual, however if you set it at something between 500 and 750 rpm you will not be far wrong. If it has the marine flywheel fitted it might be smooth at the lower end of the range, but an automotive flywheel would require a higher tickover to get smoothness.

The injector pump has a kind of turret on top. One side has the stop cable attached to its lever (to the front I think) and the other side has the throttle cable fitted. Unfortunately there are two designs of pump, but from memory:

If there are two long "bolts" about 4mm in diameter, stuck up either side of the throttle lever, then one of these adjusts maximum speed (This should be capped by a long alloy tube, wired, with a lead seal) and the other adjusts the idle speed - Operate the throttle and look at the end of the screws to see which one stops the lever as the throttle is closed. If the adjustment is badly out you may then have to adjust the cable to suit the new setting.

If there are no screws, but there is a shorter screw with, a spring under it, sticking out of the centre of the turret, then this adjusts the idle speed.

Also some pumps have an adjustment right on the top of the turret. This is to stop surging (revving up and down on idle). If this has been very badly adjusted the throttle stop screw may not have any effect below a certain speed.

There is a Dutch website with 1.5 manuals on it in English http://motoren.ath.cx/

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It will not be the bypass valve - that is part of the filter head and only works when the filter is blocked (in theory).

First ensure that the oil (not the temperature gauge) is up to running temperature. I think I would change the filter with very little hope of it curing the problem, but it is very cheap. If this is an electrical gauge, please ensure the negative (earth) on the gauge is in good condition. I do not trust these gauges, so you need to remove the warning lamp transmitter (you have fitted an adaptor piece so you can fit both senders, haven't you?) and fit an oil pressure test gauge (I think HSS will hire you one). This will tell you if its the gauge or the oil pressure relief valve.

If it is the valve you may well find that someone has either put some washers under the spring or stretched the spring.

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If it does this out of gear, I suspect its a problem with one of the injectors. I think it might be jammed with carbon and not closing. Before you go to the expense of taking them out and getting then checked (and the newer Lombardinis have a proprietary system that they have refused point blank to give me any information on - all they will say is "refer to one of our engineers") there are a couple of things you should try.

First take it for a run of several hours and try to find the opportunity to get it up to higher powers, this might burn the carbon off the injector.

Secondly, go to a motor factors (e.g. Partco) and buy sufficient Diesel Injector Cleaning Fuel Additive for your tank, add this and repeat the above.

Only if both of these fail, would I recommend getting the injectors looked at. There is a very slight chance that if you have not changed the engine oil recently, and the engine is of the newer type, the injector system control rods might be "gunged up", so changing the oil might have some effect, but it is a very long shot.

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My mechanic had a look at the engine and said that 3 of the 4 plugs were so carbonated that he couldn't get them out (even using the pressure from the engine itself), and he then sent them to the engineers to have them removed. Once all that was done, the engine started more easily, but blew a bit of pale smoke until it warmed up and was under load. The mechanic suggested that we could have the injectors serviced, and that this would solve the smoking problem, but that in the meantime there was no damage being done to the engine. While the boat was in the yard the starter motor started smoking, so the whole unit was replaced for a new one. After travelling in the boat, fairly slowly with no troubles for a day and a little bit, the engine started blowing rather a lot of white smoke after about an hour travelling. Having been told that this was probably the injectors, we continued, but I kept an eye on the temperature gauge. The smoke seemed to be worse at higher revs. After a little I noticed that the temperature had shot up to about 100 degrees, and also noted that there were drops of liquid coming out of the exhaust. I stopped the engine and waited for a bit before filling it with water. It took an awful lot. The mechanic (not the one who'd done the original work) who came out basically shook his head and said that the head would have to come off, and that until then I wasn't going anywhere. Each time he tried to start the engine water came out of the exhaust and although kicking over, it wouldn't start. There was also water coming out of one of the intakes (I'm not sure which one, sorry).

So, when the original mechanic comes out the next day, he takes off the head, expecting there to have been a fault in the new head gasket, but it's intact, and there is no visible damage to the head itself. There was water in the 3 of the pistons.

At the moment the head is with the engineers again and I'm waiting for the verdict. I've had the boat since October 2004, and since then, after running the engine 3 or 4 times a week, I've never known the water tank to take more than about half a cup, so I think it's unlikely that the problem was just a lack of water. The oil level was just below maximum when we left the boatyard. So, do you think that the work that I'd had done had anything to do with the problem, or was it just bad timing, or something I did?

First, I am pleased that you have not tried Easystart. It is all too easy to damage the engine with this stuff - your blow torch is far safer (as long as nothing catches fire). You do not say, but I suspect the cylinder head was removed to allow the glow plugs to be removed. It is very common for the tips of these plugs to snap off in the head if they are not removed, hole cleared with a small drill (7/64" I think), and refitted with copper grease every couple of years or so.

I think that the cylinder head was not refitted correctly - it really needs a special socket/spanner known as a "crows foot" to properly tighten the cylinder head bolts so I suspect it was not properly tightened down and the head gasket has now blown.

All your symptoms are typical - if a bit extreme - of a failed head gasket. I just hope the cylinder head has not cracked, warped due to incorrect tightening, or had its face damaged. In your case I would ask the engineers for the report of their pressure test - there is a chance that in drilling out the plugs they drilled into the water jacket - but it would take an idiot to do it.

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The only reason NOT to use a thermostat on an automotive base engine is if it is direct cooled - and that is a very bad idea now we have heat exchangers or keel coolers readily available.

My guess is that you engine should have something like an 88c thermostat, but I do not know if it should be a simple one or a bypass thermostat that has a large washer like object hanging from the underside. If I had to guess I would suspect it should be an ordinary one.

Please ensure that you ruin with between 30% and 50% or antifreeze in the system. This will go a long way to preventing internal corrosion.

These days, even real marine engines (as opposed to marinised engines) with direct cooling use thermostats.

Remember that people often remove thermostats to cover up other cooling system faults.

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This is an example of how to get ignored when you want help. Another similar email was sent 24 hours later. The more detail you can give me, the more help you are likely to get.

When I receive emails like yours - especially as you obtrusively can not even give me any time to give you a FREE answer, the advice I would like to give involves workshop terminology and anatomical difficulties. However that would involve me in similar conduct.

You give me no info in respect of make or type of pump, so you force me to give you a long reply when a bit of effort in locating the pump would make it easier for everyone.

1. Have you run out of water?
2. Has a pipe fallen off and you are pumping water into the bilge?
3. Has someone turned a water valve on the suction side off?
4. Centrifugal type pumps (Godwin). Yes it may well need priming if you have run out of water and the non-return valve at the inlet may well be stuck shut. Remove hose from inlet and "pick" and NRV flap with a piece of wire to ensure it can move. Fully fill tank, Turn ONE tap on, turn pump on and keep sucking at tap. This usually primes the pump. Over time the impeller on this type of pump can block with rust scales & dirt. Remove motor/pump assembly from top of pressure vessel, remove screws from impeller cover and "prod out" dirt etc.
5. Flexible impeller type pump (Jabsco Water Puppy). These are self priming as long as the impeller and housing are in good condition. Remove impeller cover and take out impeller - a wing might have broken off and jammed inside the pump so the other wings no longer seal. I would advise a new impeller every third winter (in any case the pump cover should be loosened to prevent frost damage every winter). Inspect cover and body of pump. These may well be very worn, especially if it is a plastic body, type pump.
6. Diaphragm type pump (Shureflow etc). Most likely cause is something stuck in one of the valves or possible a split diaphragm (not likely). You can strip the pump, but be aware that more than one person has had problems getting them watertight again when re-assembling them (all engineers of one sort or another).
This type of pump should be self priming.

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I am flattered that you think that an old engineer could solve a problem that both the dealer and engine mariniser appear to be unwilling to address, but it is a bit of a long shot - especially as you ask me to do it by "remote control".

Anyone with half a brains worth of basic physics would realize that if the water is not being drawn back into the engine, something else must be. The most likely thing is air, so first double check the clips on coolant hoses - engine, calorifier, skin tank, expansion tank, oil cooler(s) etc. - even double clip them with clips of the correct size, but turned through 180 degrees. The next thing to do is to inspect the engine filler cap to ensure all the rubber seals are in first class condition.

Next inspect the engine filler neck in case it got battered during transport or fitting. If it looks bent, I would be trying to get a new expansion tank/manifold under warrantee.

I do not know what type of cap is fitted on the engine or tank, if the tank cap is the pressure cap, the cap on the engine needs to be a simple cap with a rubber disk inside it to form an airtight seal. If the tank cap is just a simple vented cap things are more complicated.

You still need an airtight seal between the engine cap and filler neck, but the pressure part of the cap needs to be correct for the engine. Some Mk1 Ford Fiestas used a pressure cap of a similar design to that one I think is fitted to your engine except it had a rubber disk inside the cap instead of the more usual brass one. If you cap is like an "old" radiator cap then going to a motor factors and buying a cap of similar or slightly higher pressure, but with the rubber seal may well cure your problem.

Only after you have done all this should you consider really long shots like porous castings and slightly faulty gaskets. You could try hiring/borrowing a cooling system pressure tester and pressurising the system to see if it will leak.

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To be sure about your question I would need a diagram of your system, because I have never heard about manual control of engine temperature before.

Let us assume that your engine has a centrifugally pumped system and the lever gradually opens or closes the flow to the skin tank/keel cooler. In this configuration I would expect to find a smallish bypass pipe that allows the water to keep circulating with your valve closed, if you have this, simply connect the calorifier in place of this pipe.

Otherwise Tee off from the engine side of the valve to the calorifier and then back into the hose returning to the engine from the keel cooler/skin tank.

Both of these options will give a slower warm up, which might be prolonged on a large engine running at very low load, however as soon as the calorifier is up to temperature the engine will operate as normal. Drawing any hot water off may cause a drop in engine temperature.

As I have never installed a calorifier that is higher than the engine I can not answer your second question with any certainty. In theory the engine water pump should be capable of moving the water, but you really need to know the head that it will pump to with the engine at idle. If the pump is a "jabsco" type pump it should be fine.

My main concern is that there would appear to be no way of venting air from the calorifier and without work relating to the cooling header tank, I fear it will constantly airlock. Also the slightest air leak into the calorifier circuit would result in coolant being wasted via the header tank overflow (unless the tank is higher than the top of the calorifier coil).

Rather than ask me I would advise that you talk to someone who is well known for dealing with old Lister Engines, they should have more specific knowledge.

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The white smoke is fairly normal, but the black smoke as you describe it is typical of "overloading". This is where something prevents the engine reaching the revs set on the throttle.

Once you have checked that the prop is clear, I would suspect that the prop is too "large" and is holding the revs down. I would advise talking to someone like Steel Developments (South London) or Crowthers (Manchester way?) to find out the size they suggest and then check it against yours when the boat is next out of the water.

Operating the boat is in displacement mode and trying to drive it at more than the hull design speed or a very badly fouled hull could also cause overloading. I estimate that the maximum displacement speed of your boat to be about (without any data) and trying to drive it faster that this without a much larger engine may well cause black smoke.

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Having found some pictures/diagrams on the net I note that your engine appears to have an inline injector pump equipped with an electric stop. I have no experience of this particular engine.

If you look at the injector pump, just below where the injector pipes are fixed, I would expect to find one or two bleed screws. Often this part of the pump slopes inward. If you have these they need loosening and the priming pump operated until the fuel coming from the bleeders has no more air bubbles in it.

However the electric stop control does complicate the issue. If the engine stops like a car as you turn the "ignition" off then the "ignition" needs turning on before the pump can be bled.

If it is of this type, then your problems could have been related to the stop solenoid becoming erratic and staying open when it should have closed to allow injection.

Have you tried to rev it that high before? Was this in or out of gear?

If this was in gear, my first thought is something round the prop, however if this is the first time you tried to rev it that high, it might just be that it is overpropped.

Black smoke is an indication of over fueling and will occur if anything holds the engine revs down whilst the injector pump is delivering fuel to rev the engine up - hence my thought that its something round the prop.

It could be that someone has overtightened the stern gland, but it would get very hot if it had been.

If it does it out of gear I would hate to give an opinion, if you have not taken steps to ensure no water gets in with the fuel and into the injector pump/injectors there could be internal corrosion, but that's a long shot. A starter jammed in mesh and with a seized free wheel could cause this problem when out of gear, but I would have expected some kind of bang and a refusal to start.

I still favour a fouled prop, if its not that, and it is a totally new fault, I think you need to get an engineer to look at it.

I have replaced the valve and all seems well but I am concerned that the valve working pressure is 2bar which is the same as the output of the Shurflo pump (rated 30psi). Should there not be some leeway?

The built in pressure switch strikes again. I do not like these things, they just ensure the majority of people buy a new pump when their switch fails and often have no idea that most such pumps are adjustable for cutout pressure.

If you look at the pump end of the assembly you may well see a small hole or plug with either radial lines surrounding it, or a double ended arrow with + and one end and - at the other above it.

I think you will find an adjusting screw or small Allen key type screw at the centre. Adjust your pressure with this. If you there is no + & - sign clockwise usually increases the pressure and anti-clockwise decreases it.

Ideally you will have a pressure gauge on the system - bet you haven't - to check the actual cut out pressure. 20psi should be more than adequate, my boat runs at about 12psi.

If you have no gauge, but do have an accumulator (pressure vessel) that has a tyre valve in the top let the air pressure inside down to about 10 psi & operate the pump. When it cuts out measure the pressure of the accumulator air. This will also be your water pressure. Having established the water pressure set the accumulator air pressure to about half the cutout pressure.

If your pressure valve continues to leak, it should have a knob on top. Twist this a few times with the pump on. This lifts the valve to allow the pulse of water to flush scale etc off the valve seat.

I am a bit confused about the belt being behind the housing because normally any belt drives from the front, with the pump body behind the pulley (the end of the engine with the belt pulley is normally referred to as the front), so either you have an odd marinisation or the pump body is behind the pulley.

In my experience belt driven pumps have always been mounted by a foot, secured to an adjusting bracket by two bolts. Usually if you slacken these two bolts the pulley will tip downwards enough to allow the belt to be removed. The bolts can them be totally removed to release the pump from the engine.

I have never known the screws to snap unless they were either being over tightened or they had been "glued" in place with jointing compound. If you managed to turn them the wrong way and snapped them (quiet easy to do when access is limited and you are trying to work from the "wrong end" of the pump) you may find that once you have full access to the screws the broken stubs can
be removed by tapping round with a sharp instrument and hammer.

If that does not work, nearly any engine machinists would probably be able to sort it out at a price. There is also a setup called the "Thread Doctor" that is used by many garages.

It might be cheaper to buy a set of "Easyouts" and matching drills from an engineering/tool suppliers and try removing teh stub yourself. If they really are seized in you might have to apply a blowlamp to the body to expand the holes, but if so, you may well have to renew any rubber seals etc.

First I need to be sure that you do mean a hydraulic drive and not a hydraulic gearbox. I will answer for a hydraulic drive where the only connection between engine assembly and propshaft is a pair of flexible hydraulic hoses. If it turns out that you mean a hydraulic gearbox please email again.

Whenever these symptoms appear the first thing to do is to check that nothing has wrapped around the prop. On a hydraulic system this can cause such a pressure rise that the pressure relief valve opens and dumps oil back into the reservoir. Even if you have a gearbox check this first.

I assume that you have been keeping the reservoir toped up to level with the correct fluid? I suspect some "do everything" oil sold to farmers will be OK. If you have any data in a manual or affixed to the reservoir then use that type of oil - much depends upon the type of pump and motor.

Next make sure that the control cable is moving the spool valve (looks like a block with a number of pipes on it and a lever at one end) lever to its correct position for ahead & reverse. It might just be a loose cable anchor point at either the control or the valve end.

If all the above are OK make sure nothing has gone wrong with the way the propshaft is coupled to the hydraulic motor. The coupling may have come loose.

I think it would be worth having a look at the pump driveplate (fitted to the engine flywheel - especially if you can hear rattles or bangs coming from inside the flywheel housing.

Now it starts to get expensive.

If you can beg or borrow a high pressure hydraulic test gauge and find a way of fitting it you could measure the pressure being produced, but I have no idea what it should be because prop size has a great influence on it.

If you can see the outlet (inside the reservoir) for the PRV, see what it does whilst at normal ahead or astern speed. If it is leaking all the time either something is loading the system (fouled prop, overtight stern gland, partially seized motor etc) or a faulty valve. It might be adjustable, but I would have concerns over the 20 year old spring inside.

Finally you have to consider wear in the pump, motor, or valve assembly. If this happened suddenly I would suspect a failed seal in the valve. Once you get to this stage I think you will do better with an agricultural or plant (JCB etc) type fitter than a boatyard engineer.