KADD44 Coolant

[petem]

We've had a curious issue ever since we had the boat and looking back at the boat's service docs the previous owner had the same issue. He even went as far as having the cooling system pressure tested but never found the root cause.

Basically, the port engine doesn't like to be filled with coolant more than about 2cm above the bottom of the expansion tank. If we fill it more than this then it ends up in the bilges.

Col (formerly of this parish) was adamant that the expansion tank is too small on this engine and that 'they all do that'. His view is that the engine contains many litres of coolant so being short of some in the expansion tank is inconsequential.

Needless to say, the engine doesn't overheat (temps are the same for both engines).

Somebody else has said that the expansion tank cap could be defective but that doesn't feel like the cause to me.

Does anyone with KAD44's get the same issue? If it's relevant, the calorifier is on the port side.

 

[jrudge]

We've had a curious issue ever since we had the boat and looking back at the boat's service docs the previous owner had the same issue. He even went as far as having the cooling system pressure tested but never found the root cause.

Basically, the port engine doesn't like to be filled with coolant more than about 2cm above the bottom of the expansion tank. If we fill it more than this then it ends up in the bilges.

Col (formerly of this parish) was adamant that the expansion tank is too small on this engine and that 'they all do that'. His view is that the engine contains many litres of coolant so being short of some in the expansion tank is inconsequential.

Needless to say, the engine doesn't overheat (temps are the same for both engines).

Somebody else has said that the expansion tank cap could be defective but that doesn't feel like the cause to me.

Does anyone with KAD44's get the same issue? If it's relevant, the calorifier is on the port side.

I had this on my D12s. I replaced the cap ( as it came apart when removing it nothing to do with trying to "solve" this and it stopped.

I would not worry. If it finds its own level AND stays there then no harm done. You will be looking at a fraction of the capacity of the system.

 

[julians]

We've had a curious issue ever since we had the boat and looking back at the boat's service docs the previous owner had the same issue. He even went as far as having the cooling system pressure tested but never found the root cause.

Basically, the port engine doesn't like to be filled with coolant more than about 2cm above the bottom of the expansion tank. If we fill it more than this then it ends up in the bilges.

Col (formerly of this parish) was adamant that the expansion tank is too small on this engine and that 'they all do that'. His view is that the engine contains many litres of coolant so being short of some in the expansion tank is inconsequential.

Needless to say, the engine doesn't overheat (temps are the same for both engines).

Somebody else has said that the expansion tank cap could be defective but that doesn't feel like the cause to me.

Does anyone with KAD44's get the same issue? If it's relevant, the calorifier is on the port side.

It could well be a defective cap, they're designed to release under pressure,but can fail in such a way that they release under a much lower pressure than they are supposed to.

 

[kashurst]

have you tried swapping caps over ?

 

[scubaman]

Most of them seem to do that. Our kamd300’s did and I was adviced not to worry. They always settled to the same low level and as everything worked fine, I eventually did.

 

[jimmy_the_builder]

We've had a curious issue ever since we had the boat and looking back at the boat's service docs the previous owner had the same issue. He even went as far as having the cooling system pressure tested but never found the root cause.

Basically, the port engine doesn't like to be filled with coolant more than about 2cm above the bottom of the expansion tank. If we fill it more than this then it ends up in the bilges.

Col (formerly of this parish) was adamant that the expansion tank is too small on this engine and that 'they all do that'. His view is that the engine contains many litres of coolant so being short of some in the expansion tank is inconsequential.

Needless to say, the engine doesn't overheat (temps are the same for both engines).

Somebody else has said that the expansion tank cap could be defective but that doesn't feel like the cause to me.

Does anyone with KAD44's get the same issue? If it's relevant, the calorifier is on the port side.

It's a known kad44 issue. Mine used to do it in my t37. They would always spit out excess coolant so that there was virtually none in the expansion tank - and never overheated.

Ps why is Col ''formerly' of this parish? What happened?

 

[[2068]]

It's a known kad44 issue. Mine used to do it in my t37. They would always spit out excess coolant so that there was virtually none in the expansion tank - and never overheated.

Ps why is Col ''formerly' of this parish? What happened?

I saw Col the other day in the stealth van.
I think it’s just that he doesn’t hang out much in these forums any more.

 

[alt]

This happened in my KAD32 and I think it happens in my KAD300's too!

 

[Ian h]

Same here on my KAD 44's they sit around the lower mark. If I fill any more they just spit it out.

 

[petem]

I saw Col the other day in the stealth van.
I think it’s just that he doesn’t hang out much in these forums any more.

+1.

 

[petem]

Thanks all. Will tell the VP agent not to touch it.

I might try Kashurst's suggestion and swap the caps to see if that make any difference.

 

[Seastoke]

just a question on coolant volvo paul said my percentage was low ,on my D6 do you use genuine vp stuff or any coolant

 

[stelican]

Obvious innit more expansion on the engine with the calorifier.Don't worry about it

 

[jrudge]

I doubt that the 1 or 2 litres of coolant in the calorifier tubes will make much different to the expanded coolant given the overall capacity of the system.

 

[kashurst]

I doubt that the 1 or 2 litres of coolant in the calorifier tubes will make much different to the expanded coolant given the overall capacity of the system.

+1 my KAD 300s don't blow out the coolant with the calorifier connected either.
Something is amiss but very unlikely to be serious as your coolant level stays the same once its settled out.
I had a 63P that would blow out coolant if filled to the full level - never found the source but not a problem. A D9 did the same - anything more than minimum and it would blow out.
have you measured engine temps, thermostat housing cylinder head, crank case etc with an IR thermometer might give a clue if you compare engines. However I would try all the simple stuff first. Run your finger around the rim of the expansion vessel, should be super smooth - could just be a bit of a burr or nick in the rim.

 

[petem]

+1 my KAD 300s don't blow out the coolant with the calorifier connected either.
Something is amiss but very unlikely to be serious. I had a 63P that would blow out coolant if filled to the full level - never found the source but not a problem.
have you measured engine temps, thermostat housing cylinder head, crank case etc with an IR thermometer might give a clue if you compare engines. However I would try all the simple stuff first. Run your finger around the rim of the expansion vessel, should be super smooth - could just be a bit of a burr or nick in the rim.

Col measured temps with IR thermometer on the survey last year and engines were fine. As I said, the coolant pretty much stops escaping once it gets down to a certain level. I'll have a lose look at the rim (hadn't realised they were that sensitive to burrs / nicks).

 

[Assassin]

Its a simple issue, the expansion tank volume is too low for the amount of coolant in the system and basically it does not contain sufficient air which compresses when the engines warm, this leads to an over pressurisation of a limited volume of air and this exceeds the maximum system pressure when the engine is hot and the cap lets a little air out. It was a problem on some Volvo engined plant a few years ago and we fitted a Scania expansion tank from a lorry as it had 4X the air volume than the Volvo and it cured it.