loss of coolant - Vetus M4.15

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petermills

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I have a vetus calorifier installed on my Vetus engine. The calorifier is higher than the engine and I have an expansion tank mounted just above the calorifier. After an hour's run, the coolant level hs dropped in the engine and the coolant in the expanion tank has gone too. The car radiator style filler cap seals correctly so I am looking for ways around this problem. The plastic expansion tak has its own pressure cap o I am wondering if it would be OK to fit a sealing type cap to replace the pressure cap on the engine???
 
petermills said:
I have a vetus calorifier installed on my Vetus engine. The calorifier is higher than the engine and I have an expansion tank mounted just above the calorifier. After an hour's run, the coolant level hs dropped in the engine and the coolant in the expanion tank has gone too. The car radiator style filler cap seals correctly so I am looking for ways around this problem. The plastic expansion tak has its own pressure cap o I am wondering if it would be OK to fit a sealing type cap to replace the pressure cap on the engine???
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I would expect the pressure cap to be on the highest component, with the lower cap to be fully sealed, ie not a pressure controlling cap.
 
petermills said:
I have a vetus calorifier installed on my Vetus engine. The calorifier is higher than the engine and I have an expansion tank mounted just above the calorifier. After an hour's run, the coolant level hs dropped in the engine and the coolant in the expanion tank has gone too. The car radiator style filler cap seals correctly so I am looking for ways around this problem. The plastic expansion tak has its own pressure cap o I am wondering if it would be OK to fit a sealing type cap to replace the pressure cap on the engine???
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Does the coolant level in the expansion tank return once the engine cools down?

If not, where is it going? Into the bilges, into steam?

The expansion tank is normally vented so the cap on it is not that important. Don't change the cap on the engine/HE as it's important that it works at the correct pressure on opening and that the one-way valve works properly.

Richard
 
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RichardS said:
Don't change the cap on the engine/HE as it's important that it works at the correct pressure on opening and that the one-way valve works properly.
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Check with Vetus. I installed a calorifier kit on our Vetus diesel this year, and it came with instructions to the effect that if the calorifier was higher than the heat exchanger: a). install the header expansion tank higher still if possible, and b) replace the original pressure cap on the engine with the sealing cap provided in the kit.
 
Arcady said:
Check with Vetus. I installed a calorifier kit on our Vetus diesel this year, and it came with instructions to the effect that if the calorifier was higher than the heat exchanger: a). install the header expansion tank higher still if possible, and b) replace the original pressure cap on the engine with the sealing cap provided in the kit.
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In that case the sealing cap provided with the kit is "the cap" so that's the one that I said should not be changed. :)

Richard
 
RichardS said:
Does the coolant level in the expansion tank return once the engine cools down?

If not, where is it going? Into the bilges, into steam?

The expansion tank is normally vented so the cap on it is not that important. Don't change the cap on the engine/HE as it's important that it works at the correct pressure on opening and that the one-way valve works properly.

Richard
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]t will be the pressure cap on the header tank that controls the pressure ! If a normal pressure cap is fitted to the engine all the coolant in the header tank and probably calorifier if they higher will be lost ........

Arcady said:
Check with Vetus. I installed a calorifier kit on our Vetus diesel this year, and it came with instructions to the effect that if the calorifier was higher than the heat exchanger: a). install the header expansion tank higher still if possible, and b) replace the original pressure cap on the engine with the sealing cap provided in the kit.
Click to expand...

Which is what I said I'd expect in #2

RichardS said:
In that case the sealing cap provided with the kit is "the cap" so that's the one that I said should not be changed. :)

Richard
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No you didn't. You said it "Don't change the cap on the engine/HE as it's important that it works at the correct pressure on opening and that the one-way valve works properly".

That type of cap has to be changed for the sealing cap supplied with the kit. The pressure is then controlled by the pressure cap on the head tank

You are trying, as i have noticed you often do, to twist an incorrect answer to make out it was really correct in the first place.
 
Hello Peter

Just an alternative thought and something you should check... we had a Vetus M3.09 (very similar) on our previous boat. When we got the boat, the engine was about six years old and we noticed the following problem after a couple of months. Freshwater coolant in the engine was disappearing/dropping, I ignored this for a couple more months (mistake) and just kept topping up via the radiator cap as visually to the front of the engine everything looked fine. Access to the rear of the engine was difficult, but once I decided to investigate further. It turned out to be the heat exchanger...the rubber 'o' ring seal on the rear 'cap' that separates the sea water circulating through the heat exchanger core and the fresh water in the header tank had failed (probably before we got the boat) and had corroded the block in that entire area to such an extent that we had to buy a completely new assembly at the cost of several hundred pounds. Clearly the previous owner had not done the maintenance in this area at all, the fresh water coolant was "disappearing" into the the sea via the raw water route! Just a thought.
 
petermills said:
I have a vetus calorifier installed on my Vetus engine. The calorifier is higher than the engine and I have an expansion tank mounted just above the calorifier. After an hour's run, the coolant level hs dropped in the engine and the coolant in the expanion tank has gone too. The car radiator style filler cap seals correctly so I am looking for ways around this problem. The plastic expansion tak has its own pressure cap o I am wondering if it would be OK to fit a sealing type cap to replace the pressure cap on the engine???
Click to expand...

VicS said:
I would expect the pressure cap to be on the highest component, with the lower cap to be fully sealed, ie not a pressure controlling cap.
Click to expand...

If the coolant is leaking into the bilges then fitting the correct caps will hopefully solve it, but if it is disappearing then you will have to also find out how/where it is escaping. If you have the same type of HE that Telstarr has then very probably being lost in a similar way into the sea water.

On reflection as the loss is occurring in single 1 hour run I'd think this is very likely although you should sort out header tank and engine/HE caps.
 
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Thanks to all for your input. It seems to me that I have to start by replacing the conventional radiator style pressure cap with a fixed type. Hopefully this will solve the problem but if not I now have some alternatives to follow up on. One way or another I have to find a way of saving costs on wasted anti freeze! Surprising isn't it that its quite difficult to get hold of neat anti freeze nowadays. All of the regular suppliers are now seem to be only stocking the ready mixed stuff. By the way - the engine is quite new with only 70 hours recorded so the problem I have is not likely to be corrosion related.
 
Another thing to check is simply hose fittings. I was losing coolant and couldn't work out where it was going. Eventually found it was going to an inaccessible part of the bilges under the calorifier and the problem was insufficiently tightened hoses on the calorifier (fitted by "a professional"). It didn't leak until the system heated up which was why I hadn't initially found it. Tightened the hose fittings, no more lost coolant.
 
petermills said:
By the way - the engine is quite new with only 70 hours recorded so the problem I have is not likely to be corrosion related.
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I'd still check the integrity of the heat exchanger....Our engine was six years old, approx 300 hours.... but bear in mind it is likely the 'O' ring had failed long before the corrosion became a visible problem. The early warning sign being loss of coolant.
 
I have a similar engine which is on its third heat exchanger. First 2 corroded away on the end caps due to poor manufacture and none compatible metals and plastic. The latest one is a different casting and end fittings. It's done about 300 hours so here's hoping that it's OK.
 
Gelfie said:
I have a similar engine which is on its third heat exchanger. First 2 corroded away on the end caps due to poor manufacture and none compatible metals and plastic. The latest one is a different casting and end fittings. It's done about 300 hours so here's hoping that it's OK.
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Similar as in a Vetus?

If so, that would confirm my thoughts on our Vetus experience. The Mitsubishi base engine is excellent, but I thought the marinisation was deeply suspect. Hopefully the newer models have addressed this.
 
Latest update:I have now fitted a 'fixed' pressure cap to replace the conventional one. I have just run the engine up to operating temperature whilst watching the level in the remote header tank rise. This tank is made from plastic material with its own pressure cap. The level went up beyond the max marker. Am I right in assuming that this is OK? No fluid was lost so perhaps I have now solved the problem.
 
petermills said:
Latest update:I have now fitted a 'fixed' pressure cap to replace the conventional one. I have just run the engine up to operating temperature whilst watching the level in the remote header tank rise. This tank is made from plastic material with its own pressure cap. The level went up beyond the max marker. Am I right in assuming that this is OK? No fluid was lost so perhaps I have now solved the problem.
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That sounds fine. Dont fill it above the max mark or the excess will be ejected when the engine warms up and don't keep topping it up to the mark if it tends to stabilise a little lower.
 
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