Water "Disappearing" From Tank

[terry8]

Hi gurus,Really need your opinion. My water tank sensor lit up and I found my water tank empty so I filled the tank and also was careful to bleed the air out of the tank. After one day the tank was empty again. I took to a workshop which did a pressure test which showed that there is no leak because the pressure did not drop. The mechanic bleed the tank of air and filled it with water. In 24 hours, the tank is again low on water.What can be happening ? Where is the water going to ?Terry

 

[2wenty6]

Head gasket?

 

[terry8]

Where is this head gasket ?

 

[kgb]

Where is this head gasket ?

hiding between cylinder head and engine block.

 

[yumie]

if in 24hrs you can see the water low.. then there must be leaking somewhere and shud be very easy to detect.. radiator or hose maybe..

 

[jarance]

what model and year?

What is the mileage clocked?

Maybe the lifespan of the radiator and hose have expired.

 

[2wenty6]

He did say he had it pressure tested to verify there is no leak...but at the rate the water is disappearing, it should leave a pretty big puddle underneath the car terry8. Maybe try and make sure it really isn't leaking.

 

[jarance]

Pressure test does not not verify that there is NO leak. I used to do pressure test and it does not detect the leak.

There is one sure way to check leak. First fill the radiator with water. Warm up the engine. When it is hot, OFF the engine and check for water droplet from the bottom of the car. You might have to remove the bottom cover to see the source of the water droplets. trace the water droplets and the chances it is from the radiator connection where the rubber hose is connected. Usually you will find a hairline crack at the bottom of the plastic part of the radiator connector.

Another source of the leak is the expansion tank. I have the leak problem and actually change the radiator, expansion tank and rubber hoses to stop the leak. Note it is recommend to change the thermostats (2 nos) as well to have trouble free with the cooling system.

 

[machaplai]

beware your automatic oil filter......same as ur problem i kena b4..the water leak to gearbox, coz me few k to repair

second: also check your water hose behind your engine(L shape hose)cost 30++

 

[jarance]

beware your automatic oil filter......same as ur problem i kena b4..the water leak to gearbox, coz me few k to repair

bro, that one not the Auto oil filter. It is the heat exchanger for the ATF fluid. I heard that the water can go the ATF line if the oil seal is damaged. There is a thermostat located at the heat exchanger as well. Change it as it tend to get blocked due to the residual of the coolant after it is expired.

 

[SBB]

Just want to know how often you guys top up water to your tank? Two week once should be acceptable or it consider there is a leak? Mine after two week radiator indicator flash up.

Anyone can confirm this, please.

Thanks

 

[kgb]

topping up water is not normal. If you have to do that, means something is leaking somewhere.

 

[jarance]

Just want to know how often you guys top up water to your tank? Two week once should be acceptable or it consider there is a leak? Mine after two week radiator indicator flash up.

Anyone can confirm this, please.

Thanks

Used to top up every two weeks when I have hairline on the radiator. After changed radiator, expansion tank and hoses, 6 months also never have to top up..

 

[champion]

I too have similar problem but and hopefully less severe. I have to top up around 500ml every 3-4 weeks. I suspect is my thermostat giving way. As i can see some water marks around the fan area and also on my side bottom filter box. (e39)

 

[jarance]

I too have similar problem but and hopefully less severe. I have to top up around 500ml every 3-4 weeks. I suspect is my thermostat giving way. As i can see some water marks around the fan area and also on my side bottom filter box. (e39)

Remove the air filter box and the rubber hose connected to the radiator. You will see the hairline crack just under the connector outlet. (happen to mine).

 

[bmw7833]

The radiator and expansion tank is different part or come together when we purchase?

 

[solo]

The radiator and expansion tank is different part or come together when we purchase?

Different parts. Don't forget to replace your thermostat also.

Salut

 

[bmw7833]

Ermmmm..how come when i asked the salesperson, they said the expansion tank come together with the radiator?

 

[jarance]

Ermmmm..how come when i asked the salesperson, they said the expansion tank come together with the radiator?

bro, what model is your car? It is E46 model?

 

[solo]

Ermmmm..how come when i asked the salesperson, they said the expansion tank come together with the radiator?

Expansion tanks are always separate items. See here:-

Price of the expansion tank and labour to change it can be found in the Maintenance Thread.

Also, please find another salesman.

Salut