Annual Engine Service

Having taken Patience out for the last significant cruise of the season and with the autumn evenings drawing in, it is time to give her engine its annual service, including this year, replacing the antifreeze.

The first task was to drain the cooling system, with the engine cold, and refill with a 50/50 mix of blue ethylene glycol antifreeze and water, see earlier blog for more details. This year I was able to buy a single container of 20 litres of Triple QX Blue Antifreeze from Euro Car Parts in Cambridge for a lower price than three separate 5 litre containers. That not only saved us money, but allowed us to get the mixture right up to 50% and also keep two or three litres spare for topping up.

Then, with the engine warmed up, I changed the oil and oil filter. The sump pump on the BMC 1.8 litre engine makes this a relatively quick and easy task compared to changing the anti-freeze.

I then replaced the fuel filter, which should also be done with the engine warmed up, as it makes for easier starting after the swap. This is rather a messy job, as it is impossible to avoid all the fuel in the old filter going down into the engine sump. The old filter looked to be nice and clean, which suggests that the fuel is also in good condition. After reassembling the bowl with the new filter and sealing rings, I was very careful to make sure I bled the fuel filter of any air before trying to start the engine. Air in the system has caused headaches on previous occasions, see earlier blog.

As the tappet clearances had been checked earlier in the year, I left these for another time, but I did check the drive belt tension, which was fine.

Finally, it only remained to take the old oil and antifreeze solution down to the local recycling centre, who seem increasingly reluctant to take antifreeze solution, especially when you are trying to offload about 32 litres of it!

Servicing the glow plugs

The glow plugs are essential for starting the engine from cold and we normally switch them on for about 15 to 20 seconds before turning over the starter motor on the BMC 1.8 litre engine.  Two of the glow plugs can be seen just below the fuel injection nozzles in the above photo of the starboard side of the engine. As it's some time since the glow plugs have been checked and it is recommended that they are removed and cleaned after every 600 hours of running, I decided that this task should be undertaken as part of this year's annual engine service.

An 8 mm spanner is needed to undo the cables from their terminals (don't lose the plain washers between the nuts and the spade connectors!) and then a 12 mm ring spanner is needed to unscrew the plugs from the engine block.  It is unusual to find metric parts on the BMC engine; most of the nuts and bolts require A/F spanners.  Accessibility is limited, particularly in the case of the front cylinder glow plug, which is tucked away in an awkward position behind the alternator.  The task would be made easier with a ratchet ring spanner (not a socket spanner, as the plugs are too long), although it can be done with a simple ring spanner and a modicum of patience. If it is some time since they were last taken out, the build up of carbon may make their removal more difficult, but do persevere, as they will come loose eventually with a little gentle encouragement. You may need to keep turning them, even after the thread on the plug is clear of the tapped hole in the block.

Patience's glow plugs were generally not too carbonised and were easy to wipe clean, and all registered a resistance of about 1 ohm.  This corresponds to a current of 12 A per plug (48 A for all four) or 144 Watts per cylinder at a nominal battery voltage of 12V. However I did notice that the centre terminal of one of was slightly loose in the housing.  I ordered a replacement from Calcutt Boats and it arrived in the post less than 48 hours later - fantastic service. The resistance of the new plug was a little higher at 1.4 ohms, which is either a specification change or the build up of dirt on the old ones may be lowering their resistance slightly. 

Before replacing the plugs in the block I inserted and rotated by hand the recommended 11/64 in (4.37 mm) diameter drill into the holes to clear any carbon build-up.  It is a good idea to coat the drill with grease so that the carbon particles can be removed on the drill rather than falling into the cylinders.

Annual Service

As the clocks go back and the nights draw in, it's time to give Patience her annual service and get her ready for the winter. As well as the usual oil changes (engine and gearbox), filter changes (engine oil and fuel), checking and adjusting the tappets, checking the anti-freeze concentration, the electrolyte levels in the batteries and draining down the domestic water system, there were a couple of engine parts that needed replacing this time.
We had noticed a slight leak in the flexible high pressure oil pipe that runs from one side of the main cylinder block to the other (see photos). 

Original flexible oil crossover pipe going into port side of engine block

Flexible pipe connected to the starboard side of the engine below the fuel filter

The first photo shows one end of the pipe on the port side just below the gearbox oil cooler and the second photo shows the other end where it connects to the block below the fuel filter. Although the leak (where the flexible hose is swaged to the end fitting) wasn't yet serious, it is an indicator of a potential weakness that could be serious if it failed suddenly and led to a loss of engine oil pressure.

I discussed the problem with the very helpful people at Calcutt Boats, who are specialists in BMC marine diesels.  They recommended replacing it with a steel pipe pre-formed to the correct shape, which they stock in their chandlery as part number BM2M56598.  It was a surprisingly easy job to remove the old flexible pipe and replace it with the new one, which fitted round all the engine auxiliaries. This should last as long as the rest of the engine.

While removing the rocker box cover to check the tappets, I also took the opportunity of replacing the rocker box gasket, which had lost its flexibility and was showing signs of leaking.  The only task that remains to be done on the engine is cleaning out the heater plug ports (recommended every 600 hours running) but time was getting on so I left that for another day!

[See also last year's Annual Service blog entry]

Annual Engine Service

As it's nearly four years since the antifreeze was changed (see 5th December 2011 blog) and as it only has a recommended life of 2 years, we decided it was time to drain the water system and refill it with Triple QX Blue Antifreeze obtained from Euro Car Parts in Cambridge, which used to be Unipart. The cooling system has a total capacity of about 31 litres including the swim tank, so 15 litres of antifreeze gives almost a 50% mixture - good enough for the harshest of English winters.  As before, the system was drained by disconnecting the bottom hose from the swim tank and draining the system into the engine bilges, from where most of the coolant can be pumped into containers using the bilge pump.  The last few litres have to be sponged out, wearing rubber gloves to avoid skin contact with the ethylene glycol.

We poured the 15 litres of new antifreeze into the filler cap (using a length of rubber hose attached to a funnel) and then topped it up with about 16 litres of water.  Running the engine for a while allows the antifreeze and water to mix thoroughly and gets it warmed up for the next job - changing the oil. It's important to check the water level after running the engine for a few minutes, as further topping up may be needed. Also the bleed nut at the top of the swim tank must be used to release the air lock that is created in the top few cm of the swim tank.

Changing the oil and oil filter is very easy on the BMC 1.8 engine, as it is fitted with a sump pump that enables the oil to be pumped out into an old oil container for subsequent disposal at the recycling centre, along with the old coolant. So far, so good!

The next job was to change the fuel filter.  This is when the fun started!  For the past 5 years I have successfully bled the new fuel filter by slackening the unused blanking plug (behind the copper pipe in the above photo), followed by the union nut at the very top of the filter housing, as described in the Calcutt BMC Engine Operator's Handbook, which can be downloaded from their website.  However, for some inexplicable reason (short memory and the end of a long day), this year I followed the instructions in the BMC official engine manual.  This manual makes no mention of bleeding the top union nut on the filter housing, but instead recommends bleeding the fuel line from the filter to the injector pump at the point where it enters the pump.
When I subsequently started the engine, it ran for a few seconds and then died, as the slug of air still trapped in the top of the filter housing worked its way through to the injectors!  That meant the whole injector pump and the high pressure fuel lines to the injectors had to be bled. This is not an easy job, which on this occasion was made even more difficult by one of the bleed nuts (on the injector pump anti-stall valve) shearing off as soon as I went anywhere near it with a spanner! I removed the whole of the anti-stall valve assembly, shut off the fuel valve at the tank and went back to base in a somewhat frustrated mood.
The next morning I 'phoned Calcutt Boats and ordered a new valve assembly, which arrived first thing in the post the following day (really great service, Calcutt - thank you). This morning we returned to Patience, fitted the new valve assembly and systematically bled the whole fuel system, including the high pressure pipes to the injectors. The engine still stubbornly refused to start, so the whole procedure was repeated.  After heating the glow plugs for 30 seconds, more than the 20 seconds normally required for a cold start, and cranking it for a while, the engine finally spluttered into life - hooray!

The final task was to inspect and adjust the tension on the alternator drive belt.

Winterising

With the evenings rapidly drawing in and the end of the boating season looming, we spent a day servicing the engine and draining down the domestic water system. 
I obtained replacement filters (fuel and oil) from the excellent ASAP supplies and the oil (Morris 10W/40, recommended for canal boat engines) from the very helpful Oundle Marina Chandlery.  With the sump pump fitted to the 1.8 litre BMC engine, it's a relatively easy job to drain the old oil out into a can.  Taking out the old diesel filter is a bit messier as there is no drain plug on the bowl. There is no air filter element to replace, but I did clean round the air intake grill.  Finally I checked the belt tension and the anti freeze concentration (this was replaced last year).  I am planning to go back and check the valve clearances, as recommended by Calcutt Marine, but that can wait for another day. 
We also drained the water tank and as much of the pipework as possible.  Having experienced a cracked toilet pump valve block last year, the screws to the flange were slackened off to ensure no water remained in the block. The last couple of litres of water in the bow tank were removed with a bucket and sponge.  The inside of the tank is in really good condition with only a few rust spots visible.  The strategy of applying a coat of potable bitumen paint each year seems to be paying off.
We also fitted two replacement LED tubes in the galley.  These were obtained from the very helpful people at Campercare Products.  Although not cheap, they draw less current than the old fluorescent tubes they replace and are much brighter.  We plan to replace the other six tubes on a rolling replacement programme. 
It only remained to wander into Oundle for a pint and a steak sandwich at the Ship Inn in the High Street.  Job done!
[See also Winterising 1 ,Winterising 2, and Chief Engineer's Report - all previous blog entries on wrapping up your boat safely for winter]