Fresh water loss from Volvo 2020.

[Bav34]

Why doesn't my fresh water header tank like fresh water???

Engine is a Volvo 2020 with fresh water cooling that incidentally heats the calorifier.

Sea water apparently /forums/images/graemlins/confused.gif pumps around THAT to cool the freshwater ... I think!

The engine runs absolutely fine. Starts first time, idles v. quietly, seems to pump out what i would think is the required amount of salt water from the exhaust, doesn't smoke white, black ,pink or blue.

But after a trip of (say) 50 miles the header tank is empty, there is a small amount of blue (antifreezed) water in the sump below, when I take the rad cap off VERY little water is apparent in the header, it takes VERY little to top it up BUT the engine is developing a smell that I cannot pin down to anything other than the empty tank. A sort of hot metallicy smell .... not oil ( no leaks) not gearbox (very cool) not exhaust manifold (surprisingly cool).

It's fair to say that the header tank is actually empty 'cos there is a lip that the service book says that the water should sit at. I can actually touch some small pipes under that.

Any thoughts appreciated as we still have about 500 miles to go and everything is hanging together rather well.

No jammed doors, noxious substances in the bilges and the keel is hanging on manfully. /forums/images/graemlins/cool.gif /forums/images/graemlins/cool.gif

Went round the 5 Bavs out of 12 UK boats here last night just to warn them of the impending doom that they were all facing but they all seemed VERY relaxed /forums/images/graemlins/cool.gif /forums/images/graemlins/cool.gif /forums/images/graemlins/cool.gif

Sorry, couldn't resist that /forums/images/graemlins/grin.gif

 

[achwilan]

Same problem with my former Oceanis 311. The reason seems to be the Volvo 2020 has no expansion tank, so when the engine runs hot, fresh water escapes in the sump... you may try to attach some kind of bottle to the little plastic pipe which goes from the header tank to the sump? It was on my TBD list -low priority- some lazyness- and the engine has been working fine for 6 years -of course sipping some cooling liquid from time to time, but the boat was sold before the pb was fixed...

 

[Bav34]

Many thanks, but I'm not actually concerned about where the water is going TOO, it sits neatly in it's own little sump under the engine where oil filter change drips etc go, what I am worried about is why is it coming out and can I be damaging the engine .... although there is no apparent sign of that at the moment?

Thanks anyway.

 

[KenMcCulloch]

Maybe the pressure cap needs replacing?

 

[Kawasaki]

That's a good shout.
Check the value of the pressure cap Bav.

 

[achwilan]

I suspect it's coming out while it expanses when the engine is running hot: the (missing) expansion tank (you can find it in any car, but Volvo Penta goes cheapo...) is supposed to put the trouble right. Grumpy will feel unwell only if you forget to give him the sip he sometimes requires... just take care of how much he regurgitates /forums/images/graemlins/smile.gif

 

[johnphilip]

I have the same problem with my Volvo 2020.

Although fitted with an expansion tank I still have to fill up with about half a pint every few running hours. The coolant as you say collects under the engine.
No I don't overfill it, in fact I keep it below the level mark on the expansion tank but soon find the tank empty.
Local "Engineers" have so far failed to cure it.
More ideas please.

 

[chrisc]

just to confuse the whole thing;- My VP2030 has never needed topping up in its 7 year life.in fact I have more or less stopped checking it.(this is when it becomes dangerous ,I will check later)so what is the difference ?

 

[alan]

Also had this on my Ben 311 fitted with 2020. I found that if you left the level very slightly below the indicator (metal lip) in the heat exchanger then it was fine; if I filled it up to the actual indicator level (or above) then it spilled out of the overflow tube and under the engine. I think that what you have is "normal", just dont overfill it and add a little water when you can no longer feel any with the tip of your fingers. I had my boat for six years and was still running fine (and still is) when I sold it.

Alan.

 

[Dave_Noakes]

It may be worth checking the Thermostat is operating correctly and at the right temperature. If it is faulty, the engine could run too hot, causing the Hot Metallicy smell you have noticed and the excessive coolant loss.

Dave

 

[Csail]

Don't know if this helps but (car engine) Lotus Elise, you only fill header to the min mark to prevent the same problem. (and that is the proper way)

 

[quaelgeist2]

You may want to check all connections to/from the heat exchanger.
If the metal fasteners are not tightened correctly you may see a mix of raw and fresh water, i.e. (more or less) closed primary circuit is contaminated with raw cooling water.
As a result the engine spills more likely.
You don't have overheating, but maybe "overcorrosion" of the engine from the sea water.

 

[Heckler]

you are quite right, the hose clips that hold the rubber end caps on also depend on the tightness of, to stop fresh water when hot (hi pressure) migrating across the lands that the hose clips clamp on to the (lo pressure) sea water side.

 

[StugeronSteve]

Ditto. My 2020 blew water out of the expansion pipe everytime it was run, I kept filling it up to the ridge on the matrix as Volvo suggested and it would blow a little back out. The Volvo engineer told me to not top it up so high and it stopped blowing out. The difference between this point and the Volvo level is probably 25mm up a wine glass.

 

[Bav34]

Great stuff guys (as usual!) Given me a few things to look at. In order: I will double check connections, SLIGHTLY underfill the header tank, change the thermostat, change the rad cap.

This will take maybe a month to get a clearer picture as we don't intend to motor much from now on .... it only seems a problem after about 50 miles .... most ports are now closer than that BUT if I find anything I will report back.

Thanks again.