Vetus VH4.65 Coolant problem

[Rooney]

High everyone, I am new to canal boating but i do know the basic workings of a diesel  engines. I have bought a three and a half year old wide beam that had only made one ten hour trip from new then not used. To my amazement when engine gets to temperature it blows coolant in to expansion bottle. The coolant does not appear to circulate through the hull tanks, I have replaced thermostat / checked water pump works / checked flow between hull tanks / flow through engine by removing thermostat and turning the pump by battery drill, but when engine is run the outlet pipe gets hot at manifold and gradually works its way down the pipe to the starboard tank which all gets hot. I would have thought if the coolant was circulating both tanks should get warm, by this time expansion bottle full to the top when on max level to start with. No flow through the caloriefire either. No oil in coolant and no coolant in oil so cylinder head seems fine. I seem to think this problem is from new. Any ideas much appreciated

[Tracy D'arth]

Air locks, bleed all the circuits that don't circulate at their highest points.

 

There should be a bleed on the skin tanks, you may have to loosen a hose on the top coil of the calorifier.

 

The air trapped heating up is what causes the water to be forced out, air expands more than water when heated.

[Rooney]

1 hour ago, Tracy D'arth said:

Air locks, bleed all the circuits that don't circulate at their highest points.

 

There should be a bleed on the skin tanks, you may have to loosen a hose on the top coil of the calorifier.

 

The air trapped heating up is what causes the water to be forced out, air expands more than water when heated.

The skin tanks are self bleeding in to the expansion bottle, the calorifier i will give another go as it is horizontal and both pipes at same level.

                 Thanks for that i will give it a try. fingers crossed.

[Tracy D'arth]

Device of the devil = horizontal calorifiers.

 

Blockage in the connection between the skin tanks?

[Rooney]

Hi TD, I did check the flow between skin tanks and it was fine. I think your probably right about the air lock, must be in calorifier, i may bypass the calorifier just to try it next week and let you know.

            thanks again

[Slim]

Not too sure that an airlock in the calorifier will be the cause. They normally tee off the cooling circuit rather than be installed in series with it. Wonder if someone dumped neat anti freeze into the system. Maybe the answer if all else fails is to drain the whole system and start again.

[Rooney]

On 28/05/2022 at 10:21, Rooney said:

Hi TD, I did check the flow between skin tanks and it was fine. I think your probably right about the air lock, must be in calorifier, i may bypass the calorifier just to try it next week and let you know.

            thanks again

     Hi TD, I bypassed the calorifier by connecting both pipes together and water flowed through heating them up quickly. Hardly any  coolant came out of cal so full of air. On the down side coolant in expansion bottle still rose by about 80mm. I am now at a loss thinking is it piped up correctly ie hot from engine in to stb skin tank near top and cold out of port tank near top.

[Rooney]

On 28/05/2022 at 11:34, Slim said:

Not too sure that an airlock in the calorifier will be the cause. They normally tee off the cooling circuit rather than be installed in series with it. Wonder if someone dumped neat anti freeze into the system. Maybe the answer if all else fails is to drain the whole system and start again.

  Hi Slim, Calorifier was empty when i removed the pipes so plenty of air in there. My main problem is the engine expansion tank filling up when engine gets hot, but many thanks for giving it some thought.

[Tony Brooks]

7 minutes ago, Rooney said:

My main problem is the engine expansion tank filling up when engine gets hot,

 

It will do, that is normal as the coolant expands. What is important is by how much it expands and what is the volume of the cooling system. The tank should not "boil over" but that all depends upon the volume of the tank. A small expansion tank may "boil over" when it is working properly.

[Tracy D'arth]

If you have 2 skin tanks, you have a large volume of water. Heating it to 80 degrees will increase that volume by about 4%.

That is what the expansion vessel is for. Providing it is large enough to contain this volume plus a margin it is correct.

[Rooney]

13 hours ago, Tony Brooks said:

 

It will do, that is normal as the coolant expands. What is important is by how much it expands and what is the volume of the cooling system. The tank should not "boil over" but that all depends upon the volume of the tank. A small expansion tank may "boil over" when it is working properly.

     Hi Tony, expansion bottle size could be the problem as it is only about one and half ltr and when topped up to max line not a lot left. Skin tanks quite large, will look in to this more. Many thanks

[Tony Brooks]

2 minutes ago, Rooney said:

     Hi Tony, expansion bottle size could be the problem as it is only about one and half ltr and when topped up to max line not a lot left. Skin tanks quite large, will look in to this more. Many thanks

 

Be aware that most, if not all, marked expansion bottle are designed for automotive use and vehicles tend to have far lower coolant volumes than skin tank cooled boats and thus a lower expansion volume. Procedure to ascertain the normal running level.

 

1. Ignore any marks on the expansion bottle.

2. Ensure the system has been bled of all air.

3. Fill to brim. Go for a good run so the engine is well up to temperature, coolant will be expelled. Allow to cool until cold.

4. Whatever the level is will be the correct topping up level.

 

[Rooney]

13 hours ago, Tracy D'arth said:

If you have 2 skin tanks, you have a large volume of water. Heating it to 80 degrees will increase that volume by about 4%.

That is what the expansion vessel is for. Providing it is large enough to contain this volume plus a margin it is correct.

      Hi TD, I will calculate volume of the skin tanks  but at 4% expansion my bottle may be a bit small.

          Thanks again.

[Rooney]

14 minutes ago, Tony Brooks said:

 

Be aware that most, if not all, marked expansion bottle are designed for automotive use and vehicles tend to have far lower coolant volumes than skin tank cooled boats and thus a lower expansion volume. Procedure to ascertain the normal running level.

 

1. Ignore any marks on the expansion bottle.

2. Ensure the system has been bled of all air.

3. Fill to brim. Go for a good run so the engine is well up to temperature, coolant will be expelled. Allow to cool until cold.

4. Whatever the level is will be the correct topping up level.

 

Hi Tony, That sounds like a good method. 

                 Thanks again

[David Mack]

14 hours ago, Rooney said:

I am now at a loss thinking is it piped up correctly ie hot from engine in to stb skin tank near top and cold out of port tank near top.

Ideally cooling water should flow top to bottom in both tanks I.e. exit pipe from bottom of starboard tank should run to top of port tank. As it is you are not getting much cooling from the port tank.

[Rooney]

On 31/05/2022 at 10:42, David Mack said:

Ideally cooling water should flow top to bottom in both tanks I.e. exit pipe from bottom of starboard tank should run to top of port tank. As it is you are not getting much cooling from the port tank.

Hi Dave, My coolant from engine flows into top of stb tank out of bottom through a channel welded to hull floor and into bottom of port tank then returns to engine out of top. Would be big job to change.

                        Thanks for the info.

[Tracy D'arth]

46 minutes ago, Rooney said:

Hi Dave, My coolant from engine flows into top of stb tank out of bottom through a channel welded to hull floor and into bottom of port tank then returns to engine out of top. Would be big job to change.

                        Thanks for the info.

Considering the amount of work, I would think that the advantage in changing it over would be very small. Providing that there are baffles in the skin tanks the water should mix well enough to give adequate cooling. I have seen many hulls like this or even with baseplate tanks and they seem to work fine providing the area in contact with the canal is sufficient.

  I think from what you have said that you need a larger expansion bottle, look at some of the hire boats, many have big 5 litre bottles on the rear cabin bulkhead where they are visible.

Edited June 1, 2022 by Tracy D'arth

[Rooney]

4 hours ago, Tracy D'arth said:

Considering the amount of work, I would think that the advantage in changing it over would be very small. Providing that there are baffles in the skin tanks the water should mix well enough to give adequate cooling. I have seen many hulls like this or even with baseplate tanks and they seem to work fine providing the area in contact with the canal is sufficient.

  I think from what you have said that you need a larger expansion bottle, look at some of the hire boats, many have big 5 litre bottles on the rear cabin bulkhead where they are visible.

 Hello again TD, I think i do need a larger bottle ie 5 ltr but can only find header not expansion on internet so far. Will persevere.

               Thanks again

[Tony Brooks]

13 minutes ago, Rooney said:

 Hello again TD, I think i do need a larger bottle ie 5 ltr but can only find header not expansion on internet so far. Will persevere.

               Thanks again

 

It might be called a header tank.

[Tony Brooks]

Just been looking and agree, hard to find. Try giving Alvechurch or Black Prince a ring and asking their engineering manager what they use.

[Rooney]

On 31/05/2022 at 10:41, Rooney said:

Hi Tony, That sounds like a good method. 

                 Thanks again

 Hi again Tony, I have not tried your above method yet as my bottle is probably to small because it goes from full to the top to being empty when engine cold.

 Also been thinking as my skin tanks are about 350-400mm below top of engine and the twin coil horizontal calorifier ( by passed at moment ) is 350mm to pipe connections above top of engine, is this a lot to ask of the engine coolant pump. Could i fit a extra pump somewhere to assist with the flow.

                              thanks

[Tracy D'arth]

2 minutes ago, Rooney said:

 Hi again Tony, I have not tried your above method yet as my bottle is probably to small because it goes from full to the top to being empty when engine cold.

 Also been thinking as my skin tanks are about 350-400mm below top of engine and the twin coil horizontal calorifier ( by passed at moment ) is 350mm to pipe connections above top of engine, is this a lot to ask of the engine coolant pump. Could i fit a extra pump somewhere to assist with the flow.

                              thanks

Unnecessary.   The pump on an engine is a circulator not a positive displacement pump, it will circulate well enough. The same type of pump on a double decker bus circulates all the heaters in the bus and the engine just fine.

[Rooney]

3 minutes ago, Tracy D'arth said:

Unnecessary.   The pump on an engine is a circulator not a positive displacement pump, it will circulate well enough. The same type of pump on a double decker bus circulates all the heaters in the bus and the engine just fine.

 Hi again TD, Sounds like they are very efficient pumps, so i will forget that idea.

                              Thanks again

[Tony Brooks]

35 minutes ago, Rooney said:

 Hi again TD, Sounds like they are very efficient pumps, so i will forget that idea.

                              Thanks again

 

They are centrifugal pumps but can not produce much pressure but do shift loads of volume. That is what you want, lots of volume circulating. They won't self prime but as they should always be submerged in coolant that is relevant.

 

The calorifier coil is very likely to airlock so work out  how to install a MANUAL bleed point at  the highest point in the circuit or possibly a bleed point back to the new expansion tank, but that is more complicated.

[PaulJ]

3 hours ago, Rooney said:

 Hello again TD, I think i do need a larger bottle ie 5 ltr but can only find header not expansion on internet so far. Will persevere.

               Thanks again

Heres a starter for you

https://www.midlandchandlers.co.uk/products/expansion-tank-rdg-6364-shire-tt-011

These are a decent size (you can work out capacity easily enough by dimensions)