Water circulation problem.

[Tracy D'arth]

8 minutes ago, Alan de Enfield said:

 

Tony seems to be of the same opinion as me, we must both be wrong.

 

 

 

Sorry but yes, it is the engine oil cooler.

[NikaVinyl]

Would you suggest I take it off and flush it?

[Tracy D'arth]

Lets get to basics.

When the engine was running was there any water discharge from the exhaust overboard?  IF not its the fresh water circuit that is not passing water. We need to know this.

 

You can flush everything from the fresh water inlet all the way through to to the exhaust,  Inlet grill, any inlet filter, engine oil cooler, fresh water pump, heat exchanger matrix in the header tank, exit pipe into exhaust pipe. Many of these will involve removing hoses and the rubber cap ends off the header tank. Be careful with these, they are expensive.

 

[Tony Brooks]

11 minutes ago, marji said:

Would you suggest I take it off and flush it?

Not at this time. I would prefer you to clarify exactly which water system is not working and show/tell us exactly what is in the pipework where the raw water is drawn into the boat.

 

At present we are assuming you mean the raw water but you have not confirmed that. Once we know which system is not working and if its the raw water (as it probably is) what is in place to strain the rubbish out of the water we can advise further.  Taking a scatter gun approach to fault fining is not very successful.

 

Edited to add that once we know about your system in detail we may be able to point to more and less likely problem areas but if you can't provide that then you will just have to follow Tracy's list.

 

If there is a raw water strainer in place then once we are assured all the hose clips on the raw water system are tight  and sealing properly I would suggest that you check the raw water pump impeller, its usually only six screws. Only if that is in good condition would I start looking for other blockages.

Edited July 21, 2020 by Tony Brooks

[Tracy D'arth]

Is that really a modified tin can on the air filter connection to the inlet manifold?

 

Edited July 21, 2020 by Tracy D'arth

[Tony Brooks]

7 minutes ago, Tracy D'arth said:

Is that really a modified tin can on the air filter connection to the inlet manifold?

 

I noticed that as well and it seems to have a decent bit of tin smithing & soldering on it.

[Tracy D'arth]

Are we going to get anywhere tonight or can I get my head down?

[NikaVinyl]

Ok this is the history of the lead up to the problem.

 

My boat due to covid19 was left in the water 3 months not used, I then went to move the boat and saw that water was coming out the back hole on the the boat, exhaust hole, I always check this before I move off, it took a while but started pumping through.

 

Once moved the boat was left a few weeks at the new stop, I am allowed to stay a month instead of two weeks for reasons, so I go to the boat to clean it and make it ready for the rest of the year, and I noticed that the filter that was on the end of the hose in the river had come off, I then ordered a metal flask of amazon and made a diy filter which I had done when I first got the boat, it has proved to work, the mistake I made with the first flask filter was I used a metal bolt to connect filter to hose, four years later it had dissolved.

 

So this time I put on a plastic cable tie and fitted to the boat, I then took off the hose to the oil tube and there was green weed not much and the hose was clear, I turned on the engine and it took about 10 mins before water came through, but my engine temp remained at 90c which is where it always sits, this 10 mins is normal for my boat unless I use high revs, I went home and left the boat a week or so and then went to move it.

 

It started first time no problems, so I get off the boat and wait for the water to exit through the exhaust, but there was none at all, I gave it some revs and checked again, but still nothing and now my boat temp reached 100c so I turned it off waited for it to cool some and tried again, no joy, stopped the engine and took out the thermostat to test if it was at fault, on doing so could not replace the housing due to hard to locate local the gasket, which I have since found and should be here tomorrow.

 

So now I know that there is another inlet into my boat somewhere and that rear hose has nothing to do with the engine water.

I really thank you all for this help, If the gasket arrives tomorrow I will go to the boat and take more pics and try find this other inlet.

[PhilR]

29 minutes ago, Tony Brooks said:

Not at this time. I would prefer you to clarify exactly which water system is not working and show/tell us exactly what is in the pipework where the raw water is drawn into the boat.

 

At present we are assuming you mean the raw water but you have not confirmed that. Once we know which system is not working and if its the raw water (as it probably is) what is in place to strain the rubbish out of the water we can advise further.  Taking a scatter gun approach to fault fining is not very successful.

Having owned a boat with a Perkins 4/107 and indirect cooling (heat exchanger with wet exhaust), I am surprised why it is taking so long to diagnose the problem.  I agree it is most likely due to a blocked mudbox/strainer. It would be most unusual (and extremely bad practice) if there isn't a sea cock at the raw water inlet. There should be a mudbox or strainer above  the sea cock. The engine only needs to be run for a few seconds to ascertain whether or not the raw water system is flowing. If not stop the engine asap.

 

EDITED TO ADD - I posted the above before reading the OP's latest message. I still reckon the inlet strainer needs checking before looking at the raw water pump impeller.

Edited July 21, 2020 by PhilR

[NikaVinyl]

27 minutes ago, Tony Brooks said:

Not at this time. I would prefer you to clarify exactly which water system is not working and show/tell us exactly what is in the pipework where the raw water is drawn into the boat.

 

At present we are assuming you mean the raw water but you have not confirmed that. Once we know which system is not working and if its the raw water (as it probably is) what is in place to strain the rubbish out of the water we can advise further.  Taking a scatter gun approach to fault fining is not very successful.

 

Edited to add that once we know about your system in detail we may be able to point to more and less likely problem areas but if you can't provide that then you will just have to follow Tracy's list.

 

If there is a raw water strainer in place then once we are assured all the hose clips on the raw water system are tight  and sealing properly I would suggest that you check the raw water pump impeller, its usually only six screws. Only if that is in good condition would I start looking for other blockages.

Tony I will get as many pics as I can , I have no idea where this water inlet is now coming into my boat, I thought for 4 years it was the hose at the back, I will be taking pics every part of the engine, thank you and all of you for the help.

 

 Yes it is modified tin can, it came with the boat, I have tried to locate an original air filter but with no luck.

Edited July 21, 2020 by marji

[NikaVinyl]

45 minutes ago, Tracy D'arth said:

Lets get to basics.

When the engine was running was there any water discharge from the exhaust overboard?  IF not its the fresh water circuit that is not passing water. We need to know this.

 

You can flush everything from the fresh water inlet all the way through to to the exhaust,  Inlet grill, any inlet filter, engine oil cooler, fresh water pump, heat exchanger matrix in the header tank, exit pipe into exhaust pipe. Many of these will involve removing hoses and the rubber cap ends off the header tank. Be careful with these, they are expensive.

 

I can confirm no water is coming out of the exhaust bone dry, it's the fresh water circuit that is not passing water.

[PhilR]

?

Edited July 21, 2020 by PhilR

[NikaVinyl]

1 hour ago, PhilR said:

Having owned a boat with a Perkins 4/107 and indirect cooling (heat exchanger with wet exhaust), I am surprised why it is taking so long to diagnose the problem.  I agree it is most likely due to a blocked mudbox/strainer. It would be most unusual (and extremely bad practice) if there isn't a sea cock at the raw water inlet. There should be a mudbox or strainer above  the sea cock. The engine only needs to be run for a few seconds to ascertain whether or not the raw water system is flowing. If not stop the engine asap.

 

EDITED TO ADD - I posted the above before reading the OP's latest message. I still reckon the inlet strainer needs checking before looking at the raw water pump impeller.

It is just a case of finding it, all these years and I thought it was the hose at the back of the boat.

 

Another thing that might show the main water pump to be ok, after I removed the thermostat, the gasket disintegrated but I cleaned the area and put the housing back on and started the engine and water pumped out from that joint from the get go, this would mean that pump is working I would have thought?

[NikaVinyl]

[Steve56]

If you have run the engine and have not had water coming from the exhaust then the chances are the impeller has disintegrated. The will not last long running dry. Any blockage in the inlet can cause this. Also if the impeller has failed you should try and retrieve any broken vanes from the internal pipework as they can cause restricted flow.

[Tony Brooks]

We seem to be going round n circles here apart from the fact that the OP seems to have confirmed its the raw (sea/river/canal) water system that has failed. It is not what is normally called the fresh (engine coolant) water system that has failed.

 

No confirmation about type of boat, no more information about what is on the other end of the hose that seems to go through the back of boat or through an engine compartment bulkhead in what looks like a cruiser/yacht's engine box apart from the OP saying "I noticed that the filter that was on the end of the hose in the river had come off". If the boat has a hose in the river with some kind of filter over the end then its a very bodgy, non-standard way of installing a heat exchange cooling system so that needs sorting before any more problems are caused.

 

On the basis of information given so far WE DO NOT KNOW that the hose through the back of the boat is not the way water enters the boat.  If the photo shows it going through the transom then it might be. I think I might be able to see the angle in what may be GRP where the bottom of the hull joins the transom. If I am correct in that its a bodge.

 

This sentence may confirm that hose is the inlet "So this time I put on a plastic cable tie and fitted to the boat, I then took off the hose to the oil tube and there was green weed not much and the hose was clear, I turned on the engine and it took about 10 mins before water came through, but my engine temp remained at 90c which is where it always sits, this 10 mins is normal for my boat unless I use high revs, I went home and left the boat a week or so and then went to move it." It also confirms the raw water pump has been run dry for a considerable time so the chances are it's impeller is ruined and may have shed wings that have moved into the outlet hose and blocked things further. It also confirms rubbish from the river can and has been drawn into the system so anything could be blocked.

 

I fear the OP may have to do what Tracy said many posts ago and check/flush al the system. This is how I would proceed:

 

Rig up a hose pipe from the boat's water system unless the mooring has a water point and hose.

 

REMEMBER THAT  EVERY HOSE AND PIPE JOINT BETWEEN THE RIVER AND RAW WATER PUMP INLET MUST END UP BEING AIRTIGHT WHEN REFITTED. (Yes I am shouting).

 

Get hold of something to plug the hose that comes in from the back of whatever. If its removed form the engine oil cooler water may flood in as there sees to be no stop valve according to the OP.

 

Remove that hose from the oil cooler and plug the end. Take the hose of the other end and use the hose to back flush the cooler catching what comes out for inspection for any muck you displaced.

 

Remove the inlet hose from the raw water pump and back flush the hose. Replace both hoses on the oil cooler and the water pump.

 

Remove the back of the raw water pump and remove the impeller. Check no twigs, matches etc are stuck in the inlet or outlet ports so they damage the impeller.

 

Because its bee run dry for 10 minutes fit a new impeller and new gasket for the back of the pump.

 

Check the pump shaft for lift in the pump body. The lift should be hardly detectable. If it feels as if you could measure it then if the pump is the one I think it is the body is badly worn so it sucks air down the shaft rather than water out of the river.

 

Totally remove the outlet hose so you can ensure nothing is stuck across the bend.

 

Take both rubber end caps off the heat exchanger cum manifold and carefully poke through the heat exchanger tubes. Use a length of suitably sized electrical cable.

 

Replace hose and end caps

 

I think the problem will be solved for while but you need a proper strainer INSIDE the boat and a shut off valve on the inlet through the hull.

 

If it still overheats and hisses from the exhaust at higher speed then the mixing elbow where the water and exhaust gasses mix may be blocked with scale OR the exhaust hose may be burned on the inside and is de-laminating so the exhaust gases force rubber across the bore and blocks the hose. Excess exhaust pressure will reduce the raw water pump's outlet or stop it completely.

 

[Alan de Enfield]

1 hour ago, Tony Brooks said:

No confirmation about type of boat,

In answer to my questions OP said early in the thread :

 

River cooled yes to heat exchanger and a Norman boat.

[NikaVinyl]

T

[Tracy D'arth]

The thermostat has nothing to do with the cooling circuit from the river water, it is in the sealed engine cooling circuit which needs antifreeze to avoid corrosion.

 

Put all that back together and check out the raw water cooling circuit from the river all the way through from the water inlet to the exhaust elbow. That is inlet strainer, engine oil cooler, main heat exchanger in the header tank, river water pump, exhaust elbow and all hoses.

 

As Tony said, the pump impeller will be ruined because it has run dry. All the bits will be in the heat exchanger tubes and the hoses, you will need to get them ALL out otherwise it will block up again.

TD'

Edited July 22, 2020 by Tracy D'arth

[Tony Brooks]

further thoughts. If that hose is going through the transom in the photos and is sealed with a load of     some sort of sealer then its a leak waiting to happen. Also if it is raw the water inlet it will be drawing water from the area if the eddies that often form along the transom of a moving boat. That will  enhance the chances of any strainer blocking.

 

As it seems to be a narrow beam GRP cruiser (Norman also make wide beams) there may be compromises in respect of the water inlet position. As the OP says river water rather than canal water I think I would put a sea inlet through the bottom of the boat and glass up the hole the hose goes through. Even if the OP keeps the existing inlet position I think it still needs a proper skin fitting, isolation valve and strainer. I would always fit any strainer in a position that is just below the waterline so when you check the strainer each day a little water flushes the contents that falls out of the strainer into the boat rather than allowing it to settle outside the strainer gauze and not drawn through the system.

[NikaVinyl]

The boat is a Norman 23, the engine I was told when I bought it is a thornycroft 108, but also was told on this forum that it was a BMC 1.8D in a post I made back in 2018.

 

The filter from the river hose coming out the back of the boat I did explain that it was a DIY job made by me as there was no other filter on that hose when I bought the boat, I did try a mesh filter but it clogged up within hours, so used a metal flask with holes drilled into it.

 

I apologize if I am not offering up enough information, I just got a bit overwhelmed with the information and diagrams, but very grateful for it and am now getting a better understanding of what I need to do

 

When I get the thermostat gasket I hope today, I did say I will take pics of all the areas of the engine.

 

I  appreciate all the help 

 

 

 

[Alan de Enfield]

3 minutes ago, marji said:

I did try a mesh filter but it clogged up within hours, so used a metal flask with holes drilled into it.

That would suggest that the water is very 'polluted' with weed, and the filter was doing its job, replacing it with a filter that doesn't block means that the 'muck' is going thru the filter (the holes are too-big) and getting into your system, hence the 'green stuff' in the oil cooler.

[Tony Brooks]

Congratulations on seeking a pragmatic solution to the lack of a strainer. I think the frequent blocking you experienced with a gauze was cause by the inlet position. Even with the inlet position you have now I can't see why a strainer such as Alan showed an image of would block quickly. The strainers in most sea inlets and strainers are probably no more than 3mm diameter or less but the area is such they can contain a lot of muck before blocking. When you get moving again look at what is  swirling around the back of the boat and if there is a lot of "stuff" think about moving the raw water inlet.

 

Remember the strainer needs cleaning every day and in really dirty waters more often than that.

Edited July 22, 2020 by Tony Brooks

[NikaVinyl]

Just now, Alan de Enfield said:

That would suggest that the water is very 'polluted' with weed, and the filter was doing its job, replacing it with a filter that doesn't block means that the 'muck' is going thru the filter (the holes are too-big) and getting into your system, hence the 'green stuff' in the oil cooler.

The Filter does work I agree it is not the best filter, I am not trying to save money I just could not find a filter that would do the job, Tony said it is in an area that would draw in weeds and that I found to be very true, and the first flask filter I made got covered in like a algae and this in fact offered a finer filtration I noticed even though it got cover the water came in through it and I had a nice flow, every once in a while I would give it a few wipes with my deck broom and carry on, this lasted 4 years without issue. 

 

I do feel this is the area that the water for the heat exchanger/engine is coming in and agree that I should put in place a isolation valve and strainer once I get better photo I would take suggestions on how to go about this.

 

My Boat

 

 

 

[Mad Harold]

4 minutes ago, Alan de Enfield said:

That would suggest that the water is very 'polluted' with weed, and the filter was doing its job, replacing it with a filter that doesn't block means that the 'muck' is going thru the filter (the holes are too-big) and getting into your system, hence the 'green stuff' in the oil cooler.

I used brass wire mesh rolled into a tube shape,and inserted into the seacock.

The mesh is available on e bay and is used mainly in model making.It comes in various densities,and if I remember correctly,I used the type with 2mm spacing gaps.

On some days it did block frequently,depending on how "weedy"the canal was.

I made the strainer inspection part of my pre-cruising checks,and had no trouble with blockages.

It was simply a matter of unscrewing the cap on the seacock,pulling the strainer out and swishing it in the canal.