Water leak somewhere

[Ayesha walker]

Hi, I have a 2003 Liverpool boat with an Isuzu engine. I have to keep topping up the header tank with water. I've checked the hoses and the engine oil seems clear, yet I cannot work out where the leak is. Any suggestions? Thanks for your help. 

[Jerra]

Is it a pressurised system like a car or not?

[Bee]

OK, I'll be the first to suggest that you may be topping it up when cool, then you run the engine and it gets hot, water expands and it comes out of the little pipe by the filler and then when it cools down you look at the level and........ its gone down! So you top it up again and so on and so on. That is probably what is happening, if that is the case then you may have diluted the anti freeze and you should get the mixture right as it also contains a corrosion inhibitor.

[RichM]

Some header tanks have the "full" marker very down low in the tank in which case it can look low even when it's not. May be worth double checking.

RichM

[Top cat]

We have an Izusu too, I fill the header tank to about 2" from the top, any more and it comes out as the engine heats up. Does your engine have a small pipe coming out by where you put the water in, this is an overflow get a plastic milk bottle cut a cross in the lid and shove the pipe in it, psh the bottle down besides the engine.  If you are overfilling the header tank the water will end up in the bottle and you will know.

[Chewbacka]

2 hours ago, Ayesha walker said:

Hi, I have a 2003 Liverpool boat with an Isuzu engine. I have to keep topping up the header tank with water. I've checked the hoses and the engine oil seems clear, yet I cannot work out where the leak is. Any suggestions? Thanks for your help. 

Is this a new problem or has it always been like it?  When you fill the header tank, how full do you fill it?  How low does it go before you top it up?  If you didn't top up does the level continue to fall?

[Ayesha walker]

Thanks, everyone, who got back to me and gave me advice. If I don't top it up, the level continues to drop, exposing the metal housing inside the header tank, so it does concern me. At the moment it's manageable but topping up is not a long term solution. I have joined the RCR so will ask them to come and check, though I know it's better to work things out yourself if you can.

[Jak]

Hi. It's leaking somewhere. Provided you have plenty of antifreeze note the color and look for blue or pink water?

[Bloomsberry]

i had a coolant leak but the point of leakage was on the outside of the boat. However if you had this issue then the level of the coolant would settle to the level of the canal outside but if yours keeps dropping then this is not the issue in your case.

[Iain_S]

When you say header tank, do you mean the heat exchanger or a separate header tank? 

Has it always done it, or is this a new development?

Do you have a skin cooling tank? If so, it might be worth bleeding it.

One boat I had intimate dealings with had a similar problem : the "natural level" in the heat exchanger was low enough to allow a small amount of air to get into the top hose, and from there to the skin tank, where it stayed, to expand next time the engine was run, expelling more water from the overflow, and allowing more air into the skin tank.

Eventual cure was a flat cap on the heat exchanger and a remote header tank, to give a bit more water and expansion capacity. We also had an overflow bottle on the header tank, but that was only required because of the comparatively massive thickness and volume of the skin tank.

[Chewbacka]

If leaking inside the boat, then I would expect a small puddle to form.  If the pressure cap is defective, or as mentioned, you are drawing air into the system and expelling coolant, then I would expect the 'loss' to be via the overflow outlet by the pressure cap.  If there is a pipe fitted to the overflow, you can collect any loss in a bottle.  If that accounts for your losses then you know where to look next.  If it does not account for your loss then the coolant is going elsewhere.  I don't know the arrangement of your boat but is it possible it is leaking into the area where the stern gland drips  and you are not seeing the loss

[Top cat]

We had a small leak on a hose going to the skin tank from the header tank, trouble is the heat from the engine  evaporated  it before I could find it. To find it I wrapped tissue round the ends of the pipes, any leakage turned the tissue blue from the antfreeze even if it evaporated.  Its important to find it as a failing pipe can fail suddenly 

T C

[bizzard]

If the leak is on the engine mass and it gets hot and bakes on , it smells like curry. Whenever I opened a cars bonnet and smelt curry I knew there was or had been a coolant leak.

[ditchcrawler]

59 minutes ago, bizzard said:

If the leak is on the engine mass and it gets hot and bakes on , it smells like curry. Whenever I opened a cars bonnet and smelt curry I knew there was or had been a coolant leak.

You must eat food from some funny Take a Ways