VP 2003 problem

[Sans Bateau]

A little while ago I noticed we had some coolant mix, about .5 litre, in our bilge (just a sump under the engine really). I mopped it up and after checking that the header tank was full considered that I must have overfilled it (did I top it up???)

Thought nothing more until, then I found some more coolant, not so much, but ah!! can see where it has been leaking from a hose, tighten up the clip, job done, not so, the header tank was still full!?!?

On Friday eve, then again on Sat we motored a lot. Sunday, found coolant mix in the bilge again!

Now if there was a leak, I would fix it, top up and away we go but! The damned header is still full, there is something weird going on here!

So come on all up VP engineers and experienced peeps out there, Ive never had a VP problem before, whats going on?

PS its fresh water cooled with a calorifier.

 

[cpedw]

One plausible source of the problem is the heat exchanger. A leak between the fresh and salt sides can lead to overfilling of the coolant. It's possible that the heat exchanger tubes may have corroded or the seal between tubes and the tube plate failed.
There may be other likely scenarios too.

Regards,
Derek

 

[Ruffles]

[ QUOTE ]
It's possible that the heat exchanger tubes may have corroded

[/ QUOTE ]
BTW if the tubes are corroded you don't need to buy a new element at VP prices. You can have them tested and rebuilt at an old fashioned radiator shop such as Wessex Radiators in Bursledon.

 

[ParaHandy]

check the calorifier high pressure relief valve which will be somewhere near the calorifier ... it could be passing .. i appreciate this might question your assertion that the fluid is "coolant mix" but by the time water gets into a bilge its a bit manky ...

 

[Sans Bateau]

Understand what you are suggesting, but the engine and the calorifier would drain into seperate parts of the bilge, which are clean and always dry. The coolant is VERY bright green.

 

[Birdseye]

The symptoms you describe would be typical of a head gasket problem when the pressure of combustion or even of oil pressure forces cooling water out through the noverflow.

The only bit that doesnt figure is when you say that the coolant doesnt need topping up. It has to be either runnning short or re-filling itself from somewhere. people will suggest that the raw water is topping up the coolant but this is implausible - when hot, any hole between the two circuits would cause pressurisied coolant to leak into the unpressurised raw water, not into the bilge. Any hole from the pressurised coolant circuit into the bilge would cause air to be sucked into the coolant circuit when the engine stopped and cooled down.

Further investigation is needed. Is the coolant milky coffee coloured? Is the engine oil milky coffee?

 

[Sans Bateau]

[ QUOTE ]
Is the coolant milky coffee coloured? Is the engine oil milky coffee?

[/ QUOTE ]

No whats more the engine uses no oil!

 

[Heckler]

if the engine is coolant cooled are you sure it is a vp2003? i thought they were seawater cooled? if the coolant coming out is bright green then it is not being diluted by sea water, it could be that the calorifier is leaking between the fresh hot water and the cooling water circuit, think about it, the domestic circuit is pressurised.

 

[Bilgediver]

Some vp engines have a coolant expansion tank like on a car. When the coolant overpressures it goes to the tank and on cool down can be drawn back into the cooling system.

Do you have an expansion tank which has got filled up and needs emptying??????


John

 

[pvb]

[ QUOTE ]
if the engine is coolant cooled are you sure it is a vp2003?

[/ QUOTE ]I've heard of "thread drift", but suggesting that the guy doesn't know what sort of engine he has must be a first! /forums/images/graemlins/grin.gif

 

[Heckler]

ive talked to people who have confused a vp2003 with a vp2030 so not so stupid!! and if a vp2003 is raw water cooled then it wont be leaking "green" stuff!! although i intimated that i wasnt sure on that one!! thread drift i think not!!

 

[ruvane]

Thread drift it's not!

All examples of my boat were built with VP MD11C and I have the builders original certificate saying so. However, after removing the muck from the crankcase I found a riveted tag that states MD17!!! Fairly silly really as the 11 is 2 cyl and the 17 is a 3 cyl. Hard to mistake.

I'm only the 3rd owner and both previous owners swear that nothing major was ever done to the engine, including replacing an old 2 cyl crankcase for a new 3 cyl one!

I'm still searching for ideas on how this came about. Just goes to show, make sure you identify the engine correctly.

 

[Sans Bateau]

The engine is a 2003. All the 2000 range are available raw or freshwater cooled, one that does not come from the factory with the heat exchanger can be upgraded. I know that as I have installed an exchanger on a 2002.

To answer the question from Bilgediver, yes it does have an expansion tank which should always be about half full. Ours keeps filling up.

I am beginning to believe that the suggestion put forward by skipper-stu is the answer.

I think that when the water in the calorifier gets hot it expands, if the pressure relief valve is not doing its job, coupled with a small hole in the copper coil inside, then the very hot fresh water that is under pressure from expansion plus the pressure of the water pump, will leak into the engine cooling system.

In the absence of any other theory, I will endeavour to have the calorifier pressure tested. In the shorter term I will just shut off the taps that feed engine coolant to the calorifier.