BlueStringPudding

Hi all. I thought I would give you an update about the mysterious disappearing coolant. A boaty neighbour who knows his engines has recently returned to the UK after a couple of months away, and bless him, me and one other one of us pounced on him to ask for help with our respective engines! He's a great chap and has been so determined that my engine won't beat him, he's been working on it for three days so far, eliminating possible causes and in the process discovering other, possibly linked problems, and resolving them as he goes. If you want the quick answer to what we think is the main culprit, skip ahead to the last paragraph. But if you want to know what he's unpicked so far, read on: So, the problem we're trying to solve is that the coolant system appears to be losing 600ml plus slowly over about 2 hours, every time the engine cools down, as indicated by the indoor expansion tank, which is connected to the engine and Eber circuits. It's been losing coolant by emptying not through its overflow which would indicate engine overheating, but out through its lower pipework towards the engine, emptying slowly as the system cools. As you know from above, TM and another of my boaty neighbours checked around the engine and there were no obvious leaks that could account for this. Initial checks by this chap could also find no obvious leaks in or around the engine area either. His first thought that the initial overheat in February that started all this (whisp of steam, burnt coffee smell, boiling sound in the pipes) might have been caused by a sticky thermostat valve, but he was happy it was working fine. He was also happy that the head gasket was fine. He did discover an air lock or blockage in the engine coolant system though. (Coolant coming through the pipe at the top front of the engine felt very hot - but never hot enough to be pushed up into the expansion tank or out the overflow pipe from that tank into a bottle. However the return pipes from the skin tank were almost cold and might not have had water in it at all.) He blew through the pipes and skin tank and then flushed through what he could there with water, and now the engine coolant is hot but not too hot at the front, and warm at the return from the skin tank, as it should be. But... as the engine cooled after a few good runs, the expansion tank lost coolant at the same rate as before, every time. To quote him: where is all the water going!? He discovered that the alternator belt between the starter alternator and the water pump wasn't fully on. It felt tight at the top but underneath he could easily turn the pump by hand. So he repositioned the belt and tightened it up. But that was a bit of a red herring with regards to being a cause for possible overheating, because that alternator belt had been changed *after* the initial overheat in February, (the old alternator belt being toothless in places 😲 ) He checked the radiator cap and other parts, and gave any potential risky bits a once over and a clean, but still no improvement. He unblocked two tiny drainage holes in the bulkhead between the stern bilge and the cabin bilge, expecting water to come through from anything leaking the other side of the bulkhead. But there was no water, in fact his screwdriver came out dry. Also, uncovering the inspection hatch in the stern cabin floor showed no water. He eliminated the likelihood of there being a coolant leak from the calorifier by isolating it from the engine (as someone above suggested) joining two engine coolant pipes together to make a closed loop. But as the engine cooled after another couple of good runs, the expansion tank lost coolant at the same rate as before, till it was empty every time. But we still couldn't see where it was going to. Yesterday he eliminated any radiators leaking being the possible cause, by capping off the relevant Eberspacher pipe. But as the engine cooled after another run, guess what? The expansion tank still lost coolant at the same rate as before until it was empty. So his attention went back to the engine area. There was a horizontal line of scale a few inches above the bottom of the skin tank, the baseplate next to it being currently dry. He scraped that scale away and a while later it revealed a slow weeping leak from near the weld. Running the engine made steam come from there, confirming there is a pinhole coolant leak from the skin tank into the bilge. The weeping skin tank leak is extremely slow, just damp, so not the location of 600ml plus coolant lost from the expansion tank every time the engine cools, but I'm pleased it's been discovered. The boat is booked in for some work at the boatyard next month so repairing that is now on their to-do list. Meanwhile, the expansion tank is still losing coolant and being refilled repeatedly, but there's still no water sloshing about anywhere. This morning, he again checked the pressurised header tank that is immediately above the engine and he could tell that the level had gone down a little since yesterday. Again, no puddles anywhere, and the expansion tank in the cabin has emptied overnight as usual. So he undid the pressurised radiator cap as well as the pipes that link the expansion tank inside the cabin to it. When I then filled the indoor expansion tank with water it should have drained out where he was standing by the pressurised engine tank, but it didn't. The pipe between the two was blocked. So after a few hefty puffs he blew the pipe clear and I flushed it through with water Once the expansion tank was full and the connecting pipe clear, it was obvious that the radiator cap even when not under pressure was dripping. When checked last month and again this weekend, the radiator cap appeared to be working fine, but now it's obvious that it just doesn't seal properly. So his prevailing theory about where all this coolant has been going is that it may have been coming out of the knackered radiator cap as steam and/or drips, because the pipe from it into the expansion tank was almost but not entirely blocked - so coolant couldn't expand into the expansion tank. But the coolant wasn't collecting in puddles on the baseplate or anywhere else either to make this obvious. And although the engine thermostat appears to be working fine, on the off-chance that it may have stuck shut in the past, I've ordered a new one and he's going to replace it as a "belt and braces" way to ensure all this shouldn't happen again. So fingers crossed that the case of the mysterious disappearing coolant will have been solved. But we shall see when the parts are replaced! Thanks to TM, everyone here and my three contributing neighbourinos for their help with this. Let's hope these two replacement parts and all the unblocking of pipes and budging of airlocks has fixed it. 🤞

I've done that too, in the past

Hi. I need to find someone who can repair my cruiser stern deck hatches. They're two large steel hatches and the four hinges have rusted through. The hinges need replacing. Ideally I would like someone whose work comes recommended and who can travel to my boat on the Cov. Any recommendations, please?

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?

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.

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) 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?)

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. 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.

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.

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.

My boat originally came with curtains over the windows. These were tucked behind a horizontal rod across the bottom of the windows. The curtains were very mouldy in the folds of the fabric. So I decided to go for blinds. I have a roller blind in the bathroom, held flat against the wall by a single tiny screw-in hook and eye, which is quite subtle. And there are wooden Venetian blinds in all the other cabins. These are held by 2 of the same tiny screw-in hooks on the bottom window frame, lined up with the vertical threads running through each blind. The threads loop over the hooks and these hold the blinds parallel to the wall and are hidden by the lowest wooden slat. The slats still twist open and closed without having to unhook them.

Correct. Those things have to wait until I have a willing bilge-diving volunteer in the right place at the right time. But thanks for the advice. They're on the to-do list.

Thought I would update this again. Tues 6th Feb 8pm header tank was empty Refilled (blooping noises of air in pipes) 10.43pm only a little more coolant gone. Topped up once more but no blooping noises this time. (Added approx 670ml coolant today) Wed 7th Feb Only a little coolant gone. Topped up approx 300ml. Didn't run engine today. Thurs 8th Feb No coolant lost from header tank. Didn't run engine today Fri 9th Feb No coolant lost from header tank. Didn't run engine today -------- Tomorrow I'll run the engine again and see what happens. 🤔

*sigh" after a promising night and day, this evening the header tank has lost its coolant again. Here's how it's played out. Tues 6th Feb 9am header tank still full from yesterday 3.15pm header tank still full, started engine. 6pm turned engine off. Header tank still full but as I walked past it I heard 2 bloops as if air bubbles might have come up to the surface. Didn't see any though. 7pm header tank level gone down half an inch. 8pm header tank empty. I'll top it up again now and make note of the quantity. Thanks Eeyore.

Sorry, maybe @tree monkey just said it to me and didn't write it down here. He told me it had water in it and he seemed unconcerned about it. As for the manifold, I don't even know what a manifold is let alone it's filler, so I will leave that for the monkey man to elaborate on. Which brings me back to why has the header tank never emptied before now? Its auto-fill valve has been turned off for maybe a decade. 🤔 What could be going on that might bite me on the bum at a later date, I wonder?

Thanks Tony. Responses in bold above. 😊

Thanks everyone. Update: Mon 5th Feb Header tank empty by the morning. Filled it up. @tree monkey checked engine bay and pipes for leaks. Couldn't find anything. Thinks the red coolant pipe valves to/from the Eber were not fully closed. He closed them. Ran engine for a few hours. Header tank remained full throughout engine run. I can't remember what time he turned the engine off but some time later - 6pm - header tank level just starting to go down 7.30pm header tank empty. 7.40 I refilled header tank with coolant. 8.40pm header tank level down by about an inch 9pm header tank empty. Refilled. 10.15pm header tank still full. I went to bed Tues 6th Feb 9am header tank still full!!!!! 😮😀 I'm not going to count my coolant chickens until they're hatched, but I have some ponderances that I'm curious about:. @booke23 I intentionally didn't use any hot water last night after your idea about the coil in the calorifier. Could this be related to why the header tank, after a few refills last night, has finally stopped emptying? (Asking because I didn't fully understand the dynamics of how using hot water would increase coolant leak inside the calorifier. But I would like to understand it. Thanks) Incidentally, Tree Monkey and I tasted the tap water from the hot tap before running the engine yesterday and couldn't taste any coolant or see any colour. It doesn't mean there is no leak from one of the coils only that it wasn't obvious from the domestic water. @MtB Following on from your suggestion that the coolant is emptying from the header tank to refill a space that ought to have more coolant in it, I kept monitoring and refilling the tank last night over several hours until the level stopped going down on its own. It did eventually stop! The fact that it still hasn't emptied overnight supports that theory. Assuming it doesn't all go horribly wrong after I run the engine later, do you (or anyone else) know how I could have lost so much coolant when there isn't any *obvious* leak? I checked the header tank in December and it was full, so this emptying header tank phenomenon has only started within the last 2 months, and has been symptom-free despite running the engine a few times a week, until the discovery three days ago of the boiling/steam/burnt coffee smell/Pud panic incident. In the spirit of preventing it happening again, if it's been a very slow leak/evaporation of coolant over many months or years, why did it only show now do you think? @tree monkey Thank you for twiddling me knobs yesterday. It may turn out that the Eber pipes not being fully off might have caused the whole thing. If it was that, any coolant leaking out was ruddy sneaky not to have left signs below the Eber on the swim tank area, but I suppose it might have evaporated off if that gets hot. 🤔 Someone above (Sorry, can't see which post it's in otherwise I would tag you) suggested I work out how much fluid has gone into the header tank till it finally stopps emptying itself. Last night I put in about 750ml coolant till the tank stopped emptying. The day before about a litre in total of water throughout the day and night (it never stopped emptying though) The first day - the day it cooked - I kept topping it up hoping to cool it all down. So some of this coolant and water would have ended up going down the overflow pipe into the bilge. But I reckon that day I put in about a litre and a half thought the day. As this morning is the first time the header tank hasn't emptied while the engine is off, let's say it has taken a maximum of 3250ml (excluding what went down the overflow) to get the header tank to finally stay full. That seems like a huuuge amount of coolant to be missing from something 😮 Anyway, time will tell if it all disappears again after another engine run/cool down later today. ---------- Some related but not really pertinent info for anyone interested in my header tank set up: Tree Monkey showed a photo of where the coolant pipe T's off from the header tank to both the Eberspacher and the engine. The header tank was built not only with an overflow pipe but also an auto fill mechanism, like a teeny tiny toilet cistern (but without a lid) When I bought the boat, I (eventually) traced a slow leak in the domestic water system to this auto fill valve. A "plumber" from a boatyard that shall remain nameless came to replace it (long time ago now) but when he came he turned out to be an electrician! He didn't know what he was doing and when I got home from work I found he had replaced half of the auto-fill valve only. This changed the problem from a slow leak to a continuously filling header tank that filled faster than it could empty through the overflow! Anyway, since then, the on/off knob on the auto-filler side has been permanently in the Off position and the header tank has to be checked and topped up manually. It's no great bother but isn't how the system was designed to work. Had the auto fill been working, it's unlikely that the coolant would have run dry/steamed/smelled like burnt coffee (although the coolant would have become increasingly diluted over time). The first I would have known about any leak or missing coolant would have been the domestic water pump cycling unexpectedly when the header tank needing more top ups than usual. Anyway, I always thought it was a clever idea for a hire boat to have a self-filling header tank that keeps both the engine and the heating happy - especially as the header tank was installed behind a very heavy interior OSB wall, making it very unaccessible to hirers (good) and to future owners like me (bad). I replaced that wall panel with a hinged wooden one some years ago so at least the tank can be accessed without screwdrivers and Geoff Capes' physique. I'll try to put a photo below of the header tank set up, just for the curious among you. The pipe with the white writing leads to the T-junction piping in the engine bay that Tree Monkey posted yesterday.

Steady on with the technical jargon there. I almost understood that 😄

The pipes that go to the Eber have had their valves in the off position for as many years as it's not been used. ("Should haves" aren't very helpful just at the moment. I have a problem to resolve before reflecting on lessons learned) Thanks MtB. If it is just the Eber coolant circuit evaporating away, do you know why the header tank (if it is indeed for the Eber only) is still only retaining its water level when the engine is running? (It is as I predicted, empty again this morning and the approximate rate of emptying is described in a previous post above.) My neighbour couldn't find any leak around the Eber itself or engine. (Calorifier is possible but inaccessible to me at the moment, it'll have to be checked another time when I have help) And just so I can understand it, how come the Eber header tank pipe got so hot that it stank like burnt coffee and sounded like it was boiling? Could what little Eber coolant was left really have got that hot just from passing through the calorifier (engine hadn't been running long)? Or does it mean a leak somewhere in the Eber coolant circuit? If not necessarily a leak, should I just keep manually refilling it several times a day, or only when about to run the engine, until such a time as the fault can be found? (Coz I still need power and hot water while this is being investigated) 🤔 Thanks

Thanks Bee. The header tank can't be overfilled because it has an overflow pipe that takes excess into the outer area of the engine bay where it would eventually be expelled by the bilge pump. The smell on that first day was grim, like burnt coffee. I've not smelled it since refilling the header tank.

That's what I was told many years ago. There's no other header tank. The radiators and Eberspacher haven't been used in donkeys years. I imagine the radiators don't share the engine's coolant as such, but the one header tank feeds both calorifier coils. I'm guessing.

My boat has suddenly developed a problem. The header tank (which feeds everything - the engine/calorifier/radiators) is emptying, but we don't know where to. It's never done this before. When I re-fill the header tank and run the engine, the header tank remains full. However the water disappears a little while after the engine is turned off. This I discovered for the first time yesterday when a gawd awful smell and whisp of what may have been steam appeared above the cupboard inside the back cabin where the header tank is located. I panicked, topped the empty tank up (the pipes below it and somewhere in the engine bay making bloop-bloop air bubble noises), and I turned the engine off. I kept topping up the header tank till the blooping noises stopped and it held on to the water level. However when I checked back later the header tank was empty again. So today I tried a bit of an experiment. I topped up the empty header tank and ran the engine from 3.50pm. I turned the engine off at 7.20pm and the header tank appeared to be at the same level. The water in the header tank and the pipe immediately below it remained cool to the touch. At 8pm the header tank was still full. At 8.30pm the header tank was half full. At 9pm it was just a quarter full. By the morning I expect it'll be empty because it was this morning. My neighbour had a look round the engine bay today with the engine running and not running, and with the header tank topped up and not. He couldn't see or feel any leaks anywhere. What might cause the header tank to retain its water level only while the engine is running? And where might the coolant be leaking from so quickly when it's cooled? Any other advice please? (For info: Engine is a Kubota, 3-cylinder, boat is a 1997 Black Prince) Thanks

I'll be there along with Tree Monkey

The same thing happened to me when I was relatively new to boating. I would take the ash outside onto the back deck and pour it into a metal bucket there, to cool down. One night my CO alarm went off. It seemed that the carbon monoxide from the bucket of ash was making its way into the boat through the vents in the rear door. I had a dig around in the bucket and despite the grey ash on top, underneath it was glowing red. I don't leave my ash bucket on the boat anymore

My bathroom tiles (and stove tiles) are stuck on with the flexible version of No More Nails. A dab in each corner and one in the middle. They've stayed in place fine the 15 years I've had the boat. (But given yours had a 15 year life span, mine might all fall off tomorrow 😉 )

Hi everyone. @cheshire~rose and I were talking about how much we missed the old banters. So we thought we would test the proverbial water to see how many forumites would be interested in a get together? We are thinking about organising a Loughborough banter to blow away the cobwebs around the Most Depressing Day of the Year rather than Christmas (to avoid family commitments and as an excuse to do something fun when it's cold and bleurgh). So that would mean a suggested banter date of Saturday, 13th January 2024. Nice pub, good beer, hopefully food for people who want to eat there, Travelodge nearby for those of us who want to stay over, usual stuff. Just to get a rough idea and guage interest, who would be interested in coming along?😊