I think my engine blew up :(

[Berengaria]

<Richard searches for his black arm band>

 

Richard

LOL

Ok it's running...medium revs...got my eye on temp gauge and it's sitting at the bottom of the dial. A few faint whisps of white smoke from where the exhaust meets the engine. Nothing major yet tho....

[Naughty Cal]

Oh the tension is too much.

[alan_fincher]

If one hose has gone due to old age the betting is that the others are also in a poor state. I'd consider changing all of the other hoses in the cooling system as a precautionary measure.

Those Polar End Caps are notorious, and of a design that guarantees they don't ever tend to last many years.

 

 

Over time they distort and balloon up, which then starts to put pressure on the "seams", which eventually start to split.

 

Even on a well maintained BMC they need regular inspecton, and are the first place to look as soon as any unexpected coolant ends up in the bilge.

 

We had one go this summer.

 

The likelihood is that thoe hoses will be fine, and if you own a BMC boat for a while, you'll end up replacing that end cap several times, but never need to change a hose.

 

But, as it has overheated, there is certainly no harm in checking.

 

 

One further piece of advice, based on my own experience. It matters not how tight you think you got both the "Jubilee" clips when you replace one of those end-caps, after a week or two of use, they will have bedded in to it, and are unlikely to be tight enough, and probably leaking. You need to recheck, and retighten, as required, for a while after first fitting new ones.

[Berengaria]

Ahhh temp now at 60 from base of 40. Usually it stays steady at 80

[Chalky]

After you've run it and let it cool down (several hours) remove the pressure cap. It there's a hiss and pressure still there then you've probably got a head gasket fault. After replacing the radiator on the MG (due to another coolant leak!) I started getting the above symptom. It was also loosing a small amount of water and it was only resolved by changing the head gasket (again). On a B series petrol it's not a particularly difficult job (compared to a modern engine) and well within the scope of a DIY mechanic. I would suggest that the diesel's also DIYable.

[Berengaria]

Those Polar End Caps are notorious, and of a design that guarantees they don't ever tend to last many years.

 

 

Over time they distort and balloon up, which then starts to put pressure on the "seams", which eventually start to split.

 

Even on a well maintained BMC they need regular inspecton, and are the first place to look as soon as any unexpected coolant ends up in the bilge.

 

We had one go this summer.

 

The likelihood is that thoe hoses will be fine, and if you own a BMC boat for a while, you'll end up replacing that end cap several times, but never need to change a hose.

 

But, as it has overheated, there is certainly no harm in checking.

 

 

One further piece of advice, based on my own experience. It matters not how tight you think you got both the "Jubilee" clips when you replace one of those end-caps, after a week or two of use, they will have bedded in to it, and are unlikely to be tight enough, and probably leaking. You need to recheck, and retighten, as required, for a while after first fitting new ones.

That's the fella. Can't believe I managed to have a spare on the boat to be honest. Maybe what u said is why previous owner kept one around

[RLWP]

{snip} On a B series petrol it's not a particularly difficult job (compared to a modern engine) and well within the scope of a DIY mechanic. I would suggest that the diesel's also DIYable.

 

Yes, as long as you don't forget the tricky to access cylinder head nuts under the rocker shaft

 

Richard

[Berengaria]

Okkkkk still running....white smoke has gone completely now....for some reason the engine isn't jumping around as much as it used to but that might be the revs....temp is...approaching 80

[Naughty Cal]

No signs of any leaks?

[Berengaria]

Ok temp at 80 and holding...I put engine into tickover and it's chugging quite happily...no unusual noises smells or smoke...exhaust fumes are clear with no smoke at all...

 

No leaks that I can see Cal

[alan_fincher]

That's the fella. Can't believe I managed to have a spare on the boat to be honest. Maybe what u said is why previous owner kept one around

Yes, even if this all turns out fully OK, your very next purchase should be another one, as I know not of a way to stop them failing over time, and when you need one, you need it immediately. Shame they cost circa thirty quid, though.

 

Was your failed one that shape, or had it ballooned up, so that it had largely lost that "stepped" shape at the big end, and was now just a dome that at that open end is fully as big as what it attaches to on the tank?

 

That's the normal thing that eventually leads to failure.

 

They are a truly crap design. I have wondered about trying to add a collar of something suitable inside them, to match the biggest internal diameter the actual cap starts off with, (as opposed to the wider diameter that clamps on to the header tank), and to use a further jubilee clip, (or maybe something wider), around the outside, to try and stop the ballooning. No idea if it would help though.

 

Of course I imagine they would be less likely to balloon if you ran the cooling system un-pressuurised. My BMC has a 7psi cap on the header tank, so once hot, that nasty end cap is kept constantly under pressure from the inside, helping to distort it.

 

EDIT:

 

Not a great picture, but this shows an end cap that is considerably "ballooned", and well on the way to likely failure.

(Ignore the yellow marking, which was to show something else.....)

 

Edited January 6, 2013 by alan_fincher

[steve hayes]

Looks like your one very lucky lad

[Berengaria]

Yes, even if this all turns out fully OK, your very next purchase should be another one, as I know not of a way to stop them failing over time, and when you need one, you need it immediately. Shame they cost circa thirty quid, though.

 

Was your failed one that shape, or had it ballooned up, so that it had largely lost that "stepped" shape at the big end, and was now just a dome that at that open end is fully as big as what it attaches to on the tank?

 

That's the normal thing that eventually leads to failure.

 

They are a truly crap design. I have wondered about trying to add a collar of something suitable inside them, to match the biggest internal diameter the actual cap starts off with, (as opposed to the wider diameter that clamps on to the header tank), and to use a further jubilee clip, (or maybe something wider), around the outside, to try and stop the ballooning. No idea if it would help though.

 

Of course I imagine they would be less likely to balloon if you ran the cooling system un-pressuurised. My BMC has a 7psi cap on the header tank, so once hot, that nasty end cap is kept constantly under pressure from the inside, helping to distort it.

Comparing the new one to the old one, the old one is hugely misshapen...the new one is symmetrical and the old one is ballooned out away from the skin pipe hose...

 

Looks like your one very lucky lad

Oh man I hope so

[Dave_P]

If by some miracle your engine has survived this incident I would treat it to an oil change. Your oil should have a golden tinge not black!

 

Best of luck and hopefully all will be well.

My bmc survived a very similar incident in my early days. Like I said, they're tough old beasts. Wouldn't want to swap mine.

 

Has the OP tried starting it yet?

[MtB]

After you've run it and let it cool down (several hours) remove the pressure cap. It there's a hiss and pressure still there then you've probably got a head gasket fault.

 

Surely you have this the wrong way around. If there is a head gasket failure the cooling sytem pressure will fall to zero pretty quickly after stopping the engine. If there is pressure behind the cap half an hour after stopping the engine it means the cooling system is truly watertight, and the head gasket has probably survived.

 

On the other hand if the pressure under the cap has vanished, this can just as easily be caused by wear in the water pump bearings as by head gasket failure on this engine IIRC.

 

MtB

[Dave_P]

Whoops. My phone wasn't showing me all the posts

[RLWP]

Well, I would say you have been damn lucky! From now on, add checking the water level in the header tank to your pre-start rituals, along with the oil level in the engine

 

Richard

[Berengaria]

It's still running...ticks over fine...now running at medium revs....temp still steady at 80...dare I replace engine cover?

 

Well, I would say you have been damn lucky! From now on, add checking the water level in the header tank to your pre-start rituals, along with the oil level in the engine

 

Richard

Oh mate already added that one after this....I guess I could check oil filler after its cooled for this possible residue again?

[Naughty Cal]

I would put the lottery on this week if I were you!

[alan_fincher]

Well, I would say you have been damn lucky! From now on, add checking the water level in the header tank to your pre-start rituals, along with the oil level in the engine

 

Richard

And just to repeat, in case it is too buried in a previous post, keep checking the tigtness of both the big and small Jubilee clips on the new end cap, ideally several times over next days, weeks, and maybe even months.

 

I more or less guarantee they will loosen with time, and need screwing down some more.

 

I added a picture above that (just about!) shows the distortion that causes the failures, for those who are interested.

 

If anybody has evolved a solution to stop this happening, I'm sure many BMC owners with Polar hearer tanks would like to know about it.

[RLWP]

I guess I could check oil filler after its cooled for this possible residue again?

 

I wouldn't bother. It isn't showing up anywhere else

 

Richard

[Berengaria]

Well everyone I really don't know what to say except a huge THANKS to you all for helping me sort this out...it's definitely human error as I (a) never noticed the split and ( wasn't familiar enough with my engine as I could have been. On the plus side I'm covered in oil and sludgy water but at least I'll now be able to have a shower tonight and turn on LIGHTS and DVD and have a quiet drink to get over it all.

Really thank you so much everyone, this has been on my mind since last night and youve all been great and taught me loads!

[Philippe]

Good news all round!

 

Is your forum name the name of your boat? I was just wondering where you came by this. My interest is down to my daughter being named Bérengère which is a variant of Berengeria. It's a very unusual name (apart from being Richard the Lionheart's queen's name) and doesn't come up very often.

[MtB]

I'm very pleased you have it sorted!

 

Now you have it fixed I suggest you move away from that neck of the Oxford; there have been a spate of break-ins along there recently.

 

The culprit is widely believed to be the celebrated boast thief Mr Finch back in the area again. We saw him on Fenny Compton wharf a couple of weeks ago just before a break in there. Have a search of this forum for more info about him.

 

MtB

[alan_fincher]

I hope it is not too patronising to say I think you have undersold yourself.

 

OK, you were lucky enough to have the required bit to hand, but you have managed to work yourself through the steps necessary to get up and running, really doing very little more than seeking re-assurance at each stage, (which is sensible, as doing the wrong thing could have compounded the problem, had things been worse).

 

So well done, because I think many would have been calling out an engineer.

 

Now, one more time.....

 

1) Buy another one for next time

2) Don't think "I'll put antifreeze in when I get around to it" - get it done, and you'll not panic at the first really cold snap.

3) (Did I say!?!) Recheck those clamps every so often

 

As has been said, on this engine type, (which can be subject to these types of failures), I'd check coolant level every time, along with the oil.

Edited January 6, 2013 by alan_fincher