Quandary
Well-Known Member
After advice here, I am reporting with feedback that may be useful to someone with a similar engine. The initial task was to change the coolant which looked like it had been in there for years, not surprising when the job was attempted. First problem, the engine can only be accessed from above, kneeling by the port side, the drain plug is low down on the stbd. side of the block, tight in front of the oil filter and directly behind the riser tube for the dipstick, the primary fuel filter, fuel pipes and control cables help to complete the obstruction. When the drain cock was eventually eased, using a tiny ring spanner to lever the roll pin, nothing came out. Probing with a screwdriver revealed black gritty gunge but no liquid, a long thin screwdriver was used but this had to be shortened because of the lack of clearance at the side, still nothing. Extracted some fluid from the filler using a Pela and poured in some rad flush. Hung a bucket over the side, ran a hose to it, connected an extension hose to link the bucket to the raw water pipe from the saildrive inlet and ran the engine for half an hour. Took out the drain plug and had another go with the screwdriver digging and twisting, suddenly a jet of very black fluid which could not be directed to the jug it was supposed to discharge to because the plug was right out, mucky exhausted coolant every where. The engine holds three and a half litres of coolant but there was only space for a 2 litre jug below the flexible drain tube extension which of course came off when I tried to redirect it. I used the Pela to suck up as much mucky water as I could and cleaned up with a sponge. Putting the screw in plug back left handed with the direct obstruction of the dip stick pipe resulted in it dropping frequently in to the inaccessible grp sump in the engine bed. In the end I got it back in by rolling 12" of monel wire round it which I could use to align it with my right hand from above while applying torque with my left, not much skin on the back of my hands now. I then started flushing with water, After about ten flushes it started to clear but I was aware that the pipes to the calorifier coils would be mucky so ran the engine again and flushed three more times then drained again filled with fresh silicate cooling solution 1-1 ran again and put a bucketful of coolant though the raw water side before shutting down. No frost now, 10c tomorrow.
Lessons, Because the job is so awkward it is rarely done - (the boat had been maintained professionally up to 2 years ago, but it looked like ten years of sediment.)
Changing regularly (every second or third year) should be easier as the passages should not get blocked.
With hindsight it would probably have been simpler to disconnect the calorifier and flush that way? But perhaps less effective in cleaning out the block.
It would have been much easier to get at the drain plug with the oil filter out, in future I will do the coolant at the same time as an oil change rather than after.
Wrapping the bit of stiffish wire round the threaded plug made holding, turning and directing it in to its hole much easier.
Rad. flush (Wynnes or similar) is effective but releases an awful lot of muck to flush away.
You need an old electrical screwdiver something like 5" long used with abandon to get through the crud in the drain passage.
Few engine spaces can accommodate a 5 litre container for the discharge, with a Pela you can use a smaller container as a receiverand suck it away as it pours out.
Global warming protected this engine from frost but a few years ago it would have been at risk, the weakened coolant would not have offered much corrosion protection either.
When filled, there is a discharge from the second plastic tube, the one from the filler neck, I put a plastic bottle on the end of this to collect it.
I plan to change it again next autumn when doing the oil and filter change as I am sure it is still far from clean, thereafter ever two years if I live that long. Thanks to those that gave advice on how to tackle this task.
Lessons, Because the job is so awkward it is rarely done - (the boat had been maintained professionally up to 2 years ago, but it looked like ten years of sediment.)
Changing regularly (every second or third year) should be easier as the passages should not get blocked.
With hindsight it would probably have been simpler to disconnect the calorifier and flush that way? But perhaps less effective in cleaning out the block.
It would have been much easier to get at the drain plug with the oil filter out, in future I will do the coolant at the same time as an oil change rather than after.
Wrapping the bit of stiffish wire round the threaded plug made holding, turning and directing it in to its hole much easier.
Rad. flush (Wynnes or similar) is effective but releases an awful lot of muck to flush away.
You need an old electrical screwdiver something like 5" long used with abandon to get through the crud in the drain passage.
Few engine spaces can accommodate a 5 litre container for the discharge, with a Pela you can use a smaller container as a receiverand suck it away as it pours out.
Global warming protected this engine from frost but a few years ago it would have been at risk, the weakened coolant would not have offered much corrosion protection either.
When filled, there is a discharge from the second plastic tube, the one from the filler neck, I put a plastic bottle on the end of this to collect it.
I plan to change it again next autumn when doing the oil and filter change as I am sure it is still far from clean, thereafter ever two years if I live that long. Thanks to those that gave advice on how to tackle this task.
