salt crystals

[Guest]

Have on going problem of losing water from header tank (volvo tamd40 165hp) just completed 9 hours of use . Have noticed salt crystals around header tank & hoses nearby is this the water coming out of header tank during the 9 hours of use i must have put 8 pints of water in to keep topped up . Sea water intakes are clear . Any clues ?

 

[longjohnsilver]

Mark, 8 pints of water sounds like a heck of a lot in a relatively short period. Are you sure that you're not overfilling each time assuming the proper level to be higher than it is in reality? If that's not the case then I suggest that you look at things such as the head gasket, hoses etc. Does the engine overheat and is there any sign of an oily film in the header tank?
Out of interest what sort of speed do you get from your engines, top speed and cruising speed, and any idea of fuel consumption.

 

[Guest]

Max speed 18 knots with tide & wind behind cruise 14- 15 kts recent channel crossing 65 miles 70 gallons. I haven't let the water drop as i keep it topped up .It doesn't run hot while running but you can see water stainning around header tank.

 

[Guest]

I have the same engine c1985. I don't have any probs with it. One place worth checking(based on car engine knowledge) is the header tank cap to see if it is venting before it should.

 

[Stemar]

For what it's worth, I had a similar problem on my car. It turned out to be an invisibly tiny crack in the (plastic) header tank.

 

[longjohnsilver]

As suggested above could be the cap, but still think that you may be inadvertently overfilling it and then it will keep on venting out the excess. If you don't fill it does it run dry?

 

[Twister_Ken]

Pure speculation on my part - I'm not an engine expert - but if the crystals are salt (are they, or do they just look like salt?), surely it implies that salt water is mixing with fresh in your cooling system. If so, then the only suspect I can think of would be the heat exchanger. Is it damaged? Could your fresh water losses be caused by fresh water leaking through the exchanger into the raw water side, and getting spat out of the exhaust? As to salt getting into the fresh water, perhaps it is being sucked in to replace fresh water losses as the engine cools after use?

Certainly I'd look at the heat exchanger very carefully.

 

[longjohnsilver]

Also meant to ask whether you find water in the bilge?

 

[ccscott49]

taste it! if it is salt, you must be gettin g a leak from your raw water side, more than likely in the heat exchanger, for water, there are a few places on that engine, but I would have to have a look, somebody with a cooling system pressure tester should be able to find the leak. It is more than likely not a head gasket, if it is salt! as whee would it come from? anyway a pressure tester will tell all! good luck, colin.