Coolant magically dissapearing.

Nite · Mar 26, 2014

Hey guys,

So my Fe450 -08 is disposing of water somewhere. About 2dl / 1.5 - 2h run.
I do not have any visible leaks, I've already changed the gasket around the impeller incl. O-rings and everything, thight as ever.
I does not appear to be mixing with the oil as the oil is not milky in any way, I've had oil /water mixings before and it's not that.

So my question: Is there any where the water could "hide" ? Or is it anyway possible that it could end up in the valve-vent? I have a straight tube running from the valve-vent straight out into nature, and occasionally I can see a sort of mist comming out, but since it's damn wet here at the moment and the bike gets partially submerged from time to time, I thought the mist might just be water comming back out from the tube again?

Thoughts?

Cheers,
Nite

EddieFE · Mar 26, 2014

Good news that you have spotted it before doing major damage.
The bottom hose was cut on mine where it comes out of the water pump. With the cut being at the bottom of the pipe I did not notice the water loss until the engine blew up :cry:
Get the bike nice and warm and look around the hoses for water fizzing. Also check the exhaust is not blowing water/steam out, the smell of glycol is unmistakable. You have already said there is no leak into the oil.
My guess is that you will spot the leak once the engine temp rises especially if the bike is dry when you test it.

edelweiss · Mar 26, 2014

Do you observe white smoke? Especially after hot starts? Difficult starting when hot?

bushmechanic · Mar 26, 2014

also the spec for the water level is 10mm above the radiator core when cold

it looks wrong.

Idle · Mar 26, 2014

I'm not familiar with that unit of measurement. What is 2 dl?

Did you tighten the bleed screw by the spark plug? Did you bleed it using said bleed screw?

It's possible you have a failed head gasket. It would come out under some pressure and vaporize as soon as it hits the air. Check the front of the cylinder.

Crack the radiator cap and you prolly won't lose any coolant as there will be no pressure buildup. Some will evaporate though.

After that test, if it seems to not disappear...
Get it nice and hot, then hold a small mirror around the head/cylinder and see if you can get the mirror to fog up from the steam.

bushmechanic · Mar 26, 2014

decilitres

so 200ml ..

berger · Mar 26, 2014

A new radiator cap would probably be a good place to start. Also inspect the overflow nipple where it is soldered or pressed into the radiator filler neck for leaks. Refill the cooling system using the bleeder valve on the cylinder head. Do not over fill the system. Fill it to just 10mm over the radiator core as bushie said.

Nite · Mar 26, 2014

edelweiss said:
Do you observe white smoke? Especially after hot starts? Difficult starting when hot?

No, not at all and always starts of first kick.

Idle said:
I'm not familiar with that unit of measurement. What is 2 dl?

Did you tighten the bleed screw by the spark plug? Did you bleed it using said bleed screw?

It's possible you have a failed head gasket. It would come out under some pressure and vaporize as soon as it hits the air. Check the front of the cylinder.

Crack the radiator cap and you prolly won't lose any coolant as there will be no pressure buildup. Some will evaporate though.

After that test, if it seems to not disappear...
Get it nice and hot, then hold a small mirror around the head/cylinder and see if you can get the mirror to fog up from the steam.

I'll double check the bleedscrew, I like the mirror tecnique I'll try that aswell. And in wost case crack the radiator cap and see if that helps.

Cheers
Nite.

bushmechanic · Mar 26, 2014

you can usually smell even the smallest amount of coolant while the bike is running if it is leaking into the cylinder or exhaust or even onto the engine ..putting glycol coolant on anything hot makes a distinct smell

if you wet a rag with some coolant and wipe it on a hot exhaust you get the idea

edelweiss · Mar 27, 2014

if you have no smoke, the water doesnt go under head, but goes probably into air, away from the engine. the mirror test could help in this case. also checking the radiator cap and radiator overflow is a good idea. if you apply a new radiator cap designed for higher pressuse (higher than original 1,4bar), the symptoms will be more visible. ...and if its not radiator cap or overflow, start looking for a new head gasket.

Taffy · Mar 27, 2014

if you had a perfectly running bike and now you don't I suspect that the waterpump seal is failing and the place to look is a weep hole in the front face of the engine. of course a new gasket at the W/P is no guarantee either! the covers can be bent and there is little contact surface.

try running the engine up to hot with the tank off and check the radiator for steaming and look around the engine.

don't be scared to get the engine quite hot!

regards

Taffy

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Coolant magically dissapearing.

Nite

EddieFE

edelweiss

bushmechanic

Idle

bushmechanic

berger

Nite

bushmechanic

edelweiss

Taffy

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