Where is all the coolant going?

[Eeyore]

43 minutes ago, BlueStringPudding said:

Unfortunately not on my own, they're way too heavy for me. I don't know if any of my burly neighbours are around this weekend. If they are, I'll ask them to help.

 

What do you need photos of other than what Tree Monkey has already photographed here? I'll try to get the correct areas in the pics for you. 

@BlueStringPudding I've added that info, got fat fingers this morning. We might even get to see the bleed points at the top of the skin tank.

 

Regarding the possible build up of gases in the system; when was the last time the coolant/antifreeze solution was changed? and did the system get flushed at that time?

 

Edited February 10 by Eeyore

[tree monkey]

1 hour ago, Eeyore said:

@BlueStringPudding are you able to move the deck boards for a few photos from above?

 

A photo showing where the pipe marked in yellow goes? Best guess is that point "C" connects in some way to what looks like the skin tank, marked in red at the bottom of the photo.

 

A photo showing where "B" and "A" go to/come from.

 

Does @tree monkey remember what type of cap (marked in green) is fitted, pressure or plain?

 

This is the cap.

 

[MtB]

3 minutes ago, tree monkey said:

This is the cap.

 

 

 

Photo of the underside of the cap please!! 

 

 

[Tony Brooks]

16 minutes ago, MtB said:

 

 

Photo of the underside of the cap please!! 

 

 

 

Whilst we can not be 100% certain, that it is 99.9% certain that it is a pressure cap and possibly set at 0.9 bar. If it were not  a pressure cap then it is almost certain that with coolant in the little high level expansion tank it would have leaked out from the metal to metal diaphragm that is normal under the cap. There is no sign of this on the cylindrical thing. Furthermore, the lack of signs of leaks from under the pressure cap suggests it is not relying on the usual metal diaphragm type seal as found on most pressure caps, so we can guess with a fair degree of accuracy that it has a rubber seal under the top of the cap.

 

Note: you can occasionally find that the metal diaphragm will form a water tight seal to the top of the filler neck, but once they get a bit older, then usually do not. Hence, not saying it is 100% certain that it is a pressure cap.

 

It looks an odd sort of system, but once you work it out it really is no different to those that use a remote cooling header tank, except it uses the CH header tank as an expansion vessel and a length of pipe that is common with the Eberspacher.

 

Edited to add that 0.9 bar is about 13 psi so a very common pressure cap rating (except on Polar/Bowman manifolds with rubber end caps, they are more likely to be 6psi or less.

 

Edited February 10 by Tony Brooks

[BlueStringPudding]

2 hours ago, Eeyore said:

@BlueStringPudding are you able to move the deck boards for a few photos from above?

 

A photo showing where the pipe marked in yellow goes? Best guess is that point "C" connects in some way to what looks like the skin tank, marked in red at the bottom of the photo.

 

A photo showing where "B" and "A" go to/come from.

 

Does @tree monkey remember what type of cap (marked in green) is fitted, pressure or plain?

 

Yes, I know from memory that the (yellow) pipe leads to the (red) skin tank. I've no idea about the location of a bleed point for it though (which tells you how likely it is to have been bled, unless that's ever been done by someone servicing the engine in the past, it's clearly not been done by me).

 

I'll go see if any of my beefy-grr neighbours are about and willing to hoist up the deck lids for a photo op. Brb. 

[Eeyore]

@BlueStringPudding I've just been on a bigger screen, and this looks interesting. I think I can see 6 or 7 jubilee clips. Perhaps a photo of this if possible. Wouldn't be surprised if this is a twin skin tank set up at this point.

Edited February 10 by Eeyore

[Tony Brooks]

29 minutes ago, BlueStringPudding said:

Yes, I know from memory that the (yellow) pipe leads to the (red) skin tank. I've no idea about the location of a bleed point for it though (which tells you how likely it is to have been bled, unless that's ever been done by someone servicing the engine in the past, it's clearly not been done by me).

 

I'll go see if any of my beefy-grr neighbours are about and willing to hoist up the deck lids for a photo op. Brb. 

 

It should have a bleed point with the system configured as it is, and it will typically be right in the horizontal top section of the tank or on the tank side, tight up against top. It could be a dome headed screw, a square headed plug, a hexagon headed "bolt" or a radiator bleed point. OI am sure there are others as well.

 

As long as the system does not run low on coolant, you boil the engine up, or you get an engine fault they can go for years without needing bleeding, but when they do need bleeding you get a lot of coolant forced out of the overflow when it warms up.

 

Once again, looking at the plumbing, it is 99% certain that the yellow hose is the hot flow into the skin tank.

 

Pipe A in the diagram is almost certainly the cold return from the skin tank and B the flow from gearbox oil cooler to the engine water pump. It looks as if a plain hose on the oil cooler changes to a convoluted hose that Eeyore has marked in red. That change MIGHT account for the hose clips he mentions.

 

Apart from the cylindrical remote from the engine coolant header tank and the use of the CH Header tank as an expansion tank with the shared pipe I can't see anything odd or unusual about the system.

 

 

 

 

 

 

[Eeyore]

@Tony Brooks said ."It looks as if a plain hose on the oil cooler changes to a convoluted hose that Eeyore has marked in red. That change MIGHT account for the hose clips he mentions."

 

Ahh yes, could be. Looks to be a bit tight in there.

 

@Tony Brooks said. "Apart from the cylindrical remote from the engine coolant header tank and the use of the CH Header tank as an expansion tank with the shared pipe I can't see anything odd or unusual about the system."

 

Agreed. I quite like that the neck for the filler on the blue cylinder has been fitted at an angle so that there is always an expansion gap above the coolant when filling from cold.

Edited February 10 by Eeyore

[BlueStringPudding]

3 hours ago, Eeyore said:

@BlueStringPudding are you able to move the deck boards for a few photos from above?

 

A photo showing where the pipe marked in yellow goes? Best guess is that point "C" connects in some way to what looks like the skin tank, marked in red at the bottom of the photo.

 

A photo showing where "B" and "A" go to/come from.

 

Does @tree monkey remember what type of cap (marked in green) is fitted, pressure or plain?

 

Bear with me @Eeyore. Could only get one side of the deck hatch up and now it's stuck there, so I've been hanging upside down with a torch and phone trying to take photos under the other deck hatch. I've rather broken myself but at least I didn't drop the phone or torch in, or indeed myself in! Below is a pic of the (yellow) pipe that goes into the (red) skin tank,  plus the other paraphernalia above and to the right of the engine. 

 

 

The only other pipe I can see attached to the skin tank is this fat one towards the stern: 

 

Any sort of bleed valve isn't obvious to me from above the deck, but you guys might see it coz you know what you're looking for. 

51 minutes ago, Eeyore said:

@BlueStringPudding I've just been on a bigger screen, and this looks interesting. I think I can see 6 or 7 jubilee clips. Perhaps a photo of this if possible. Wouldn't be surprised if this is a twin skin tank set up at this point.

Oh blimey. That I'm afraid is even less visible from above the closed hatch. I've tried to take a couple of pics but my hands are shaking now so they're very blurry. Sorry. I can't really tell if that pipe leads to another skin tank or not. 

 

[Tony Brooks]

I can't see any bleed valve, but there is a very good chance that the tank is self bleeding when the pressure cap is removed for initial filling and initial running up/bleeding. The "to the skin tank" pipe is vertical with a tight elbow straight into the tank AND it is at the highest point in the tank, so any air in the tank should easily find its way out of the skin tank and into the cylindrical header. (Being ex hire I am not surprised it to has beeen built as self bleeding as possible)

 

Unfortunately, it probably means getting up close and personal with a running engine, but I think that if, with the CH header tank empty, you took the filler cap off the cylinder, ensure it is full of coolant, and then run the engine until you see lots of movement below the filler, then fill to the brim and refit the pressure cap, it will have bled the skin tank and the engine.

 

In fact, now I see more of the setup, I think you have been filling and bleeding the tank each time you topped up the CH header tank. It is just that there was so much air in the system, the expansion blew a lot of coolant out of the overflow.

[BlueStringPudding]

19 hours ago, Tony Brooks said:

It seems that you have not yet monitored any overflow from the header tank, so that makes further diagnosis and comment difficult, but the talk of glugging might suggest there was air/gas in the system. If there is/was then the amount of water expelled as it is heated will gradually get less. There is also no mention of bleeding/venting the skin tank that again makes everything more difficult.

 

If you are filling the header tank right up to the overflow, then it will always vent coolant as the system eats up and then APPEAR to have lost coolant when it cools again. Once you are sure everything is back to normal, fill the header tank to the overflow. get the system nice and hot. Allow it to get really cold and note the coolant level. That will be the topping up level.

 

I ran the engine for 2 hours this morning. Now the engine is cooling down, the header tank coolant level is dropping. And although I can't reach it I can see from above the end of the overflow pipe from the (Eber/joint) header tank and the area below it. Both appear dry, suggesting that's probably not where the coolant is going.

(I'll get a closer look another time when I'm feeling a bit better) 

13 minutes ago, Tony Brooks said:

I can't see any bleed valve, but there is a very good chance that the tank is self bleeding when the pressure cap is removed for initial filling and initial running up/bleeding. The "to the skin tank" pipe is vertical with a tight elbow straight into the tank AND it is at the highest point in the tank, so any air in the tank should easily find its way out of the skin tank and into the cylindrical header. (Being ex hire I am not surprised it to has beeen built as self bleeding as possible)

 

Unfortunately, it probably means getting up close and personal with a running engine, but I think that if, with the CH header tank empty, you took the filler cap off the cylinder, ensure it is full of coolant, and then run the engine until you see lots of movement below the filler, then fill to the brim and refit the pressure cap, it will have bled the skin tank and the engine.

 

In fact, now I see more of the setup, I think you have been filling and bleeding the tank each time you topped up the CH header tank. It is just that there was so much air in the system, the expansion blew a lot of coolant out of the overflow.

 

Thanks for the advice, Tony. The overflow pipe for the header tank just empties onto the shelf of the swim/skin tank so what doesn't trickle off into the wet bilge, I'm guessing might just evaporate from the heat of the skin tank. (I'm guessing?)

Edited February 10 by BlueStringPudding

[Tony Brooks]

Just now, BlueStringPudding said:

 

I ran the engine for 2 hours this morning. Now the engine is cooling down, the header tank coolant level is dropping. And Though I can't teach it I can see from above the end of the overflow pipe from the header tank and the area below it. Both appear dry, suggesting that's not where the coolant is going.

(I'll get a closer look another time when I'm feeling a bit better) 

 

Sorry to hear both (the coolant still dropping, and you feeling no so bright). If nothing is coming out of the overflow while the engine is heating up, then my theory on what was happening is out the window. I fear that leaves leaks, not only to the inside of the boat or into the calorifier, but potentially from the outer skin of the skin tank.

 

I think it may be time to isolate the calorifier by clamping the two hoses identified many posts ago between two pieces of wood each, or clamps or mole grips. Then if the problem goes away, you know it is a leaking calorifier coil (although I don't see why domestic water pressure is not forcing any water from the overflow (unless the pump cutout pressure is less than about 13 psi).

 

If that does not show a fault, I think that it may be a good idea to see if a yard or engineer can put a cooling system pressure tester on the cylindrical header. That would give lots of time to search around the engine for leaks.

[Eeyore]

@Tony Brooks I didn't mention clamping the pipes in my earlier post because it looks very much like the hoses are the same age as the engine; might be a bit risky. Certainly looks self bleeding.

 

 

Edited February 10 by Eeyore

[Tony Brooks]

3 minutes ago, Eeyore said:

@Tony Brooks I didn't mention clamping the pipes in my earlier post because it looks very much like the hoses are the same age as the engine; might be a bit risky. Certainly looks self bleeding.

 

 

 

Well, yes, but they don't look very perished around the hose clips, and I was thinking about something BSP might be able to do. If she is correct about nothing exiting the overflow, I fear it might be time to get an engineer in with a pressure tester.

[jacko264]

Could it have  a head gasket blowing into the water  jacket ?  Then blowing the water out  the header tank . As the engine cools it draws the water back out the header tank ?

Graham

[Tony Brooks]

3 minutes ago, jacko264 said:

Could it have  a head gasket blowing into the water  jacket ?  Then blowing the water out  the header tank . As the engine cools it draws the water back out the header tank ?

Graham

 

It could be except BSP has said, today, that she can see no signs of water near the overflow outlet.

[BlueStringPudding]

16 minutes ago, Tony Brooks said:

 

It could be except BSP has said, today, that she can see no signs of water near the overflow outlet.

 

In the vain and desperate hope that I'm mistaken, I'm going to try and find a way to trail that header overflow pipe into a container or something. I've just got to wait till I've got help. 

[jacko264]

Grasping at straws is there any water in the sump with the oil

im just trying to figure it all out 

I must stress  it’s only ideas 

Graham

[Eeyore]

So the two "red" hoses will be connected either directly by the convoluted hose or via a second skin tank.

@BlueStringPudding No bilge diving for you today please, just wait till you have some help.

[BlueStringPudding]

1 hour ago, Eeyore said:

So the two "red" hoses will be connected either directly by the convoluted hose or via a second skin tank.

@BlueStringPudding No bilge diving for you today please, just wait till you have some help.

Thanks Eeyore. A kindly neighbourino opened the deck hatches for me this morning. (No I didn't think to take my phone but any pics wouldn't have been any better than those above) Judging by eye, I think those two pipes that you've marked are joined directly without a second skin tank in-between. Also the swim ledge on that side doesn't have the telltale indentation that the skin tank on the other side does.

 

@Tony Brooks I've wedged a bottle under the header tank over flow pipe to measure if some comes out next time. The overflow pipe was almost horizontal so when I tilted it downwards there was a trickle of coolant that came out (possibly just as a result of my slightly overfilling the tank earlier this week, who knows) There is currently about an inch of coolant remaining in the bottom of the header tank. I'm not sure whether to top it up to just below the overflow outlet again before I next run the engine? 

Edited February 11 by BlueStringPudding

[Tony Brooks]

1 hour ago, BlueStringPudding said:

I'm not sure whether to top it up to just below the overflow outlet again before I next run the engine? 

 

I would fill to the overflow, empty your bottle, the run-up to temperature and compare the volume expelled with the amount needed to top up when the engine has gone cold. if both are similar then it is just expansion and  probably nothing nasty. Very little or nothing is expelled, there is probably a leak. If you suspect a leak, a pressure tester will help find it unless it is in the calorifier or the skin tank.

[Bod]

20 hours ago, jacko264 said:

Grasping at straws is there any water in the sump with the oil

im just trying to figure it all out 

I must stress  it’s only ideas 

Graham

To expand on this. 
what colour is the oil on the dipstick?

Black or fresh oil coloured all ok. 
Grey or grey and thick, BAD do not run engine. 
 

Bod

[tree monkey]

21 minutes ago, Bod said:

To expand on this. 
what colour is the oil on the dipstick?

Black or fresh oil coloured all ok. 
Grey or grey and thick, BAD do not run engine. 
 

Bod

Oil is fine, it's the first thing I checked 

[jacko264]

If you fill the header tank it will not have any expansion room when the engine gets hot  is there a fill to line on the tank ?

[Eeyore]

@BlueStringPudding Hi, any update on the coolant issue please? or still the same?

By the way did you check under the floor at the back of the boat?

Edited February 14 by Eeyore