Skin take pipe issue

[Robbie Barr]

Just had a new engine installed (Canaline 38) and it's a beaut. It is a great engine, however within a few days or running it (yet to cruise) at about the 3 hour mark of idling, the pipe (i'm assuming from) the skin tank came off pissing coolant in to my bilges and causing the poor engine to run dry, overheat and cut out.

 

I assumed that when it was installed the jubilee clip wasn't tight enough and re fitted the pipe (rubber hose on to a metal outlet pipe) put the hose on as far as possible so that it was past the flange and tightened the jubilee clip as far as it would go. I couldn't even try ripping it off. I refilled the engine with coolant as per the engines instruction manual and ran it, she was fine (thankfully no head gasket damage) and I let her run again checking every ten minutes in the engine bay. Again at the 3 hour mark roughly this pipe ripped itself off and all the coolant spilled out.

 

Does anyone with a better knowledge of engines than me know exactly what it is that's causing this amount of pressure to built up?

 

Thanks!

[john6767]

Certainly no expert, but if it is a pressurised system surely it must have a filler cap with a pressure relief valve in it, if there is no pressure relief it's a bomb! Is there expansion space for that water when it gets hot? The person to ask about this must be the fitter of the engine.

[MtB]

How are you adding coolant? This would normally be added via a header tank with a cap which also performs a 'pressure relief valve' function. The cap should have the pressure at which it opens marked on it. I suspect yours (incorrectly) has a cap with no PRV built in.

 

The second problem you have is why the engine is overheating to the degree that the pressure in the cooling is rising so high.

 

Mike

[NB Lola]

Is the skin tank the proper size?

[ditchcrawler]

How are you adding coolant? This would normally be added via a header tank with a cap which also performs a 'pressure relief valve' function. The cap should have the pressure at which it opens marked on it. I suspect yours (incorrectly) has a cap with no PRV built in.

 

The second problem you have is why the engine is overheating to the degree that the pressure in the cooling is rising so high.

 

Mike

If its full of coolant, I.e. no air and there in no pressure relief cap then it won't need to get that hot to pressurise.

[OldGoat]

Is the skin tank the proper size?

 

?? Isn't this a matter of excess pressure or pure overheating, I wonder.

 

If the cap is a blanking cap (NOT a good idea without a separate header tank), then IME the addition of a skin tank adds considerably to the amount of fluid in the system which was never designed with that in mind. Perhaps the supplier thought you were going to install a separate remote header tank - this is quite common because leaving an air gap in the engine tank is not sufficient to cope with skin cooling.

 

 

That happened to me when I started using the skin tank as my fresh water cooling system just couldn't cope with extended river cooling - I kept losing the extra coolant and then the heat exchanger tubes were insufficiently covered to umm - exchange the heat!! Fitted a vented remote header and now the engine runs too cool....

[NB Lola]

I fitted an external skin tank for a canaline 42 and it runs like a dream

[bizzard]

What temperature does the engines temp gauge read at the moment the hose pops off?

[Pretty Funked Up]

System wasnt fully bled properly and you got an airlock?

 

A blanking cap put on for transport has been left on?

Edited September 19, 2012 by Pretty Funked Up

[blackrose]

If the system is properly bled and the engine's header tank has the correct pressure cap (probably 1 bar), then this shouldn't happen. Either the coolant pressure in the engine is too great or the pipe isn't fixed to the outlet properly.

 

With the engine cold, take off the pressure cap and make sure it works by pressing the inner bit against its spring. With the cap off, locate the small overflow pipe in the side of the pressure cap housing. Find the other end of the overflow pipe (you might just be able to pull the pipe up away from the engine to make this easier, but note how it's routed before doing this), then blow down the pipe to make sure it's not blocked. Re-route the pipe back in the same position.

 

Does the outlet from the skin tank have something for the hose to grip onto or is it just a section of plain pipe or plain elbow that's been welded onto the tank? I also have two jubilee clips on each skin tank outlet on my boat turned 180 degrees apart.

Edited September 19, 2012 by blackrose

[sharpness]

this is quite common because leaving an air gap in the engine tank is not sufficient to cope with skin cooling.

/quote]

Thats not the case with our Beta, we dont have a header tank which I believe is normal. We certainly havent had any problems with long river runs on the Severn.

 

Steve

[RobinJ]

Just had a new engine installed (Canaline 38) and it's a beaut. It is a great engine, however within a few days or running it (yet to cruise) at about the 3 hour mark of idling, the pipe (i'm assuming from) the skin tank came off pissing coolant in to my bilges and causing the poor engine to run dry, overheat and cut out.

 

I assumed that when it was installed the jubilee clip wasn't tight enough and re fitted the pipe (rubber hose on to a metal outlet pipe) put the hose on as far as possible so that it was past the flange and tightened the jubilee clip as far as it would go. I couldn't even try ripping it off. I refilled the engine with coolant as per the engines instruction manual and ran it, she was fine (thankfully no head gasket damage) and I let her run again checking every ten minutes in the engine bay. Again at the 3 hour mark roughly this pipe ripped itself off and all the coolant spilled out.

 

Does anyone with a better knowledge of engines than me know exactly what it is that's causing this amount of pressure to built up?

 

Thanks!

[Higgs]

Don't take responsibility for it. If it's a very recently fitted engine, you must put the problem in the lap of the fitter/'s company.

 

Has it actually got to its first service, which should come pretty quick after fitting and usually carried out under guarantee by the fitters of the engine. I think.

Edited September 20, 2012 by Higgs

[Robbie Barr]

Thanks for all your very helpful replies, pretty much summing up what i thought.

 

I'm taking no responsibility for this, it's only been in for a week if that (has just under 7 hours on it). Just like to do some research of my own.

 

It's being looked at on monday, I did notice the thin plastic pipe from the pressure cap has melted where it sat against the engine block, this may be the first problem.

[RLWP]

Thanks for all your very helpful replies, pretty much summing up what i thought.

 

I'm taking no responsibility for this, it's only been in for a week if that (has just under 7 hours on it). Just like to do some research of my own.

 

It's being looked at on monday, I did notice the thin plastic pipe from the pressure cap has melted where it sat against the engine block, this may be the first problem.

 

It could be - especially if it is now blocked and there is no other way of venting the system

 

Richard

[bizzard]

If the filler tank is higher than the rest of the cooling system including the skin tank you should be able to comfortably run your engine on idle without the filler cap on, this should prevent any pressure build up, and if you blip open the throttle now and then should disperse any trapped air in the system, just keep a strict eye on things and the temp gauge whilst doing so.

Are the hoses made of reinforced rubber? They might be made of some kind of perhaps soft slippery Silicone which the clips will sink into when hot and lose their retaining power especially if the skin tank pipes are just smooth bits of pipe stub as they often are.