I think my engine blew up :(

[The Bagdad Boatman (waits)]

Nobody work on their own car any more. We used to re bore and rebuild Austin 7s and morris minors as youths plus BSA moterbikes. The japanese stopped all that with fine engineering 200k engines are common. Boat engines can be linked to heat the hot water and to the uninitiated there are pipes that run from the water tank to the engine, unfortunately there is a heat exchanger barrier to separate the two. Its the same with calculators nobody uses a slide rule and whatever is displayed must be true.

[Dovetail]

My BMC lost oil pressure a few years back when running and stopped the engine in a lock but then started again only for a short time until stopping once more I then realised something was wrong and soon diagnosed loss of oil pressure. I also found out my oil pressure gauge was also faulty.

 

If you have an oil pressure gauge or an oil pressure warning light fitted you may have noticed something not normal with them?

[Taslim]

Some people have no idea about certain things, its just the way things are. I have no interest in so called smart fones to me they are kids toys and I have no idea or want to know of how their various bits work and never will. I have a friend who is in his field a renowned genius worldwide but I kid you not he cannot check his car engine/water levels or wire a 13amp plug !!

I think those of us that have boated for many years forget how green we were ourselves sometimes

 

Tim

 

That gets my green vote.

 

taslim.

[alan_fincher]

On re-reading this full screen on my laptop, rather than trying to squint at it on my phone, I note.......

 

I went outside and was met with white smoke and a very hot engine.

 

Now I would suggest that if the OP is not very mechanically knowledgeable, what they have interpreted as "white smoke" may in fact be the results of the engine having overheated to the point it has boiled its cooling water.

 

When this happens, there is every chance of something that looks far more "smoke like" than just the steam you might expect, particularly as hoses and engine get very hot, and "rubber" and oil vapours tend to add to the mix.

 

If it is "keel cooled" with a skin tank, and one of those horrible Polar or Bowman header tanks with big rubber connectors on the end, there are countless ways coolant can be lost slowly over time, and once the level drops below the critical point you still have a full circuit for the water to travel round, overheating will occur within minutes.

 

I still think this is by far the most likely explanation. Whether the engine will have survived the experience remains to be seen, but a lot of BMCs have been through it, and do, I'm guessing.

[RLWP]

On re-reading this full screen on my laptop, rather than trying to squint at it on my phone, I note.......

 

 

 

Now I would suggest that if the OP is not very mechanically knowledgeable, what they have interpreted as "white smoke" may in fact be the results of the engine having overheated to the point it has boiled its cooling water.

 

When this happens, there is every chance of something that looks far more "smoke like" than just the steam you might expect, particularly as hoses and engine get very hot, and "rubber" and oil vapours tend to add to the mix.

 

If it is "keel cooled" with a skin tank, and one of those horrible Polar or Bowman header tanks with big rubber connectors on the end, there are countless ways coolant can be lost slowly over time, and once the level drops below the critical point you still have a full circuit for the water to travel round, overheating will occur within minutes.

 

I still think this is by far the most likely explanation. Whether the engine will have survived the experience remains to be seen, but a lot of BMCs have been through it, and do, I'm guessing.

 

I agree Alan. Guessing at a distance (WARNING), I would say boiled dry and the head gasket gone. Id prefer to be able to see the engine though to remote guesswork

 

Richard

[MtB]

I agree Alan. Guessing at a distance (WARNING), I would say boiled dry and the head gasket gone. Id prefer to be able to see the engine though to remote guesswork

 

Richard

 

The one thing not yet accounted for is the sparks flying from the exhaust mentioned by the OP on re-starting it the first time. Hopefully just bits of hot carbon falling off the inside of the exhaust system and not the piston heads crumbling.

 

REGINALD chucks sparks of glowing carbon from the exhaust when opened up wide sometimes. Very pretty in the dark...

 

MtB

[nb Innisfree]

There is often an impression that some people have 'natural ability' when it comes to mechanical or electrical stuff or any other field.it's not true, those who don't consider themselves to have a certain talent e.g. "My brain isn't designed to understand electrics" have simply not given themselves enough time, ok some have more curiosity and enthusiasm which makes it easier to apply themselves to learning but the bottom line is that to become competent in a certain area involves time and effort, and sometimes it can be very frustrating.

 

A close relative has commented that it's ok for me when it comes to typing on the computer keyboard as I 'know' where each key is and he has to look for them. He can't accept that I know where they are because I've spent many hours findind my way around the keyboard enabling my brain to slowly programme itself through continuous repetition, wheras he gives up thinking I have a certain talent that he doesn't and doesn't realise that in fact I am quite a slow learner in all things.

[churchward]

The one thing not yet accounted for is the sparks flying from the exhaust mentioned by the OP on re-starting it the first time. Hopefully just bits of hot carbon falling off the inside of the exhaust system and not the piston heads crumbling.

 

REGINALD chucks sparks of glowing carbon from the exhaust when opened up wide sometimes. Very pretty in the dark...

 

MtB

It could be bits of anything that is hot enough from as you say the exhaust to other bits of carbon build up elsewhere or possibly bits of head casket. Hopefully nothing too serious.

[blackrose]

Go easy Blackrose. The important thing here is to get him going again and teach him about boats in the process.

 

N

 

Sorry no offence meant to the OP. I only said what everyone else was thinking.

[BlueStringPudding]

In the nicest possible way I'm afraid you were. What on earth made you think that your engine coolant came from your domestic water tank?

 

Lighten up, mate. People aren't born with this knowledge.

And as anyone who's read some of my posts over the years will know: My engine coolant water DOES come from the main water tank via an automatically filling cistern-like header tank that serves both the engine coolant circuit and and the central heating. It's designed that way to prevent the exact kind of problem the OP has had.

[Berengaria]

Hi everyone...phew lots of replies but I've just managed to get my phone back into action so I'll prioritise a little and use what daylight I've got to concentrate on the engine now I've got more info, thanks everyone.

In short I've located the header tank, the reason I'd not identified it was because the pressure cap is quite far under the decking and not visible...gonna need to fashion some sort of flexible dipstick for this one

I didn't overfill the oil, I carefully checked dipstick and glugged it up to the max mark

And yeah I am very green when it comes to engines but that's why I asked for help - so I can learn this stuff. I self thought myself computer use and have been a videogame designer now for 14 years so I guess it's just how I tend to learn stuff

Thanks everyone again for the help n advice and I'll let you know about the water once I've got something in there

[Chalky]

I agree Alan. Guessing at a distance (WARNING), I would say boiled dry and the head gasket gone. Id prefer to be able to see the engine though to remote guesswork

 

Richard

 

I had an MBG (same base engine, just petrol not diesel) that blew a hose and lost its coolant just after pulling off the M69. Very similar symptoms of overheating and refusing to re-start until it had cooled down. The head gasket had blown and the engine wouldn't run until it had cooled down a bit and allowed it to partially re-seal. With coolant added it would run for a few seconds on tick over then fail again due to the heat build up. It would run longer on a fast idle but there was a danger of damaging the cylinder block / head due to scorching. I ended up coming home on a low loader and changing the head gasket and hoses so I could get to work on Monday. My suspicion is head gasket - if you don't know much about engines get someone who does to look at it before trying to run it to avoid causing other problems.

[RLWP]

Where are you moored?

 

Richard

[Berengaria]

Hi Im at Fenny Compton past the Wharf Pub, thanks

[luctor et emergo]

Sorry no offence meant to the OP. I only said what everyone else was thinking.

 

And possibly a lot politer too... 8-)

[Iain_S]

One bit when checking the water : Theo's engine looks like it's indirect raw water cooled, i.e. there is coolant circulating through the engine and header tank, and a seperate "circuit" of canal water through the heat exchanger in the header tank and out with the exhaust. The other common arrangement is a keel cooler, which is usually a thin tank welded on the side of the swim. If you follow the pipes from the header tank/heat exchanger, you should be able to find what you've got.

 

If it has a keel cooler, and the water level has been low, there will be a large air lock in the keel cooler, which almost always needs a bleed screw or cap on the top of the keel tank slackened or removed until water comes out.

 

Iain

[Berengaria]

Ok everyone I've located the problem. The big black rubber seal attaching the header tank to the pipe leading to the skin tank has a 2 inch split in it which I'm sure is not gonna be helping

[RLWP]

Ok everyone I've located the problem. The big black rubber seal attaching the header tank to the pipe leading to the skin tank has a 2 inch split in it which I'm sure is not gonna be helping

 

So that explains where the water went. Next you need to find out what has happened to the engine

 

Be careful about using the starter motor - see if you can pull the engine over on the fan belt, or with a socket on the crankshaft. If the cylinders are full of water (becasue the head gasket has gone) you could end up bending a rod

 

Richard

[jelunga]

Ok everyone I've located the problem. The big black rubber seal attaching the header tank to the pipe leading to the skin tank has a 2 inch split in it which I'm sure is not gonna be helping

Calcutt Boats on the Oxford stock these, also Midlands Chandlers. Depends of the make of header tank Polar was one popular make. There mat well be a part no on the rubber thingy so you get the right one.

[Berengaria]

Thanks Richard. Yes I can manually turn the engine. I also topped up the water to about 1.5 inches below the overflow

 

Btw the split is on the top of the seal so unless I stick my finger in there it's holding water.

 

Thanks jelunga. I'll take a look right now at the seal.

[alan_fincher]

Calcutt Boats on the Oxford stock these, also Midlands Chandlers. Depends of the make of header tank Polar was one popular make. There mat well be a part no on the rubber thingy so you get the right one.

If it is a Polar header tank, it will almost certainly have "Polar" cast in to it. The "rubber" parts do usually carry their number, likely to be A3/783 if it is the end that has the connection to the skin tank on, as stated. (The other end blanking cap being A3/703, I think).

 

I believe Bowman heat exchangers also have identification cast in, but am not sure if the "rubber" parts carry identification.

 

You need the correct ones - they do not have the same size connection. If you are lucky it will be Bowman, as the parts generally seem to be cheaper!

 

There seems to be a fair chance the engine may have suffered head gasket or other failure from the overheating though, so I echo the advice not to just replace split parts and fire it up, hoping all is well.

 

"Jelunga" your geography is slightly out - Calcutt are on the Birmingham main line of the GU. OK, it's not far from the Oxford, but certainly not on it!

[Berengaria]

Ok part number is polar a3/783

I have a pretty good collection of replacement parts in storage and have another new one with me. It's got a big rubber cap over the large end so I'm gonna try fitting it now

 

Assuming i manage to fit it, in which will be only my second attempt ever at engine maintenance after changing a battery....how the heck will I know if theres head gasket damage?

[Nickhlx]

Well..... I am impressed with his un-daunted approach and willingness to help and diagnose the problem himself !! I can see its a big issue for those that don't understand or aren't familiar with such things

 

All credit to you, sir !!

 

Nick

[Theo]

One bit when checking the water : Theo's engine looks like it's indirect raw water cooled, i.e. there is coolant circulating through the engine and header tank, and a seperate "circuit" of canal water through the heat exchanger in the header tank and out with the exhaust.

 

 

That's exactly what it is.

 

The other common arrangement is a keel cooler, which is usually a thin tank welded on the side of the swim. If you follow the pipes from the header tank/heat exchanger, you should be able to find what you've got.

 

If it has a keel cooler, and the water level has been low, there will be a large air lock in the keel cooler, which almost always needs a bleed screw or cap on the top of the keel tank slackened or removed until water comes out.

 

Iain

 

Never had a keel cooled boat so I wouldn't know!

 

 

N

[Naughty Cal]

Ok part number is polar a3/783

I have a pretty good collection of replacement parts in storage and have another new one with me. It's got a big rubber cap over the large end so I'm gonna try fitting it now

 

Assuming i manage to fit it, in which will be only my second attempt ever at engine maintenance after changing a battery....how the heck will I know if theres head gasket damage?

 

By getting someone who knows what they are doing to have a look for you.

 

Tell tale signs are usually ( but not always) water in the oil or oil in the water. Oh and steam!