Coolant loss with no trace of leak

[MiloAcclaim]

Hi All,

I have a problem where I keep on losing coolant from my 2001 VXII Acclaim V6.
I noticed it the other day when the car overheated. The cooling system took
over 3 litres of water.
After that I keep on checking the coolant level where I can see that about
half a litre dissapeares every time after my 45 minute drive to work.
There is absolutely no trace of water leakage at all!

Yesterday it was a bit cooler day than usual and I lost no coolant at all!

Any ideas, please?

I might replace the radiator cap and see whether the situation improves.

Another question for you: When I turn the A/C on, should BOTH fans start up or
only one?
At the moment I can see that when the A/C is on, only the left hand fan runs.

Many Thanks

Milo

[accentstencil]

I would suggest replacing the radiator cap.
I'm not sure about if both fans should operate with the A/C on but I can say both mine do, but it's a WH with a V8 so it might be different

[pablo]

Have a look under the oil filler cap on the rocker cover. If you have a whitish sludge build up, this would indicate an internal leak, more than likely inlet manifold gasket.

[acarmody]

Also check around the heater tap, very common leakage point.

[Sladdo]

Also check welch plugs. Have a really good look at the side tanks of the radiator too

[faroogoo]

Check around the plastic end tanks on your radiator hairline cracks around the fan mounting tabs & other mounting tabs are common..

[Craig54]

I have the same problem on a vx no signs of leaking no sludge under the cap and the oil is clean as but every week ot takes about 2 lts of water???????

[Longman]

First thing is to check your oil (dipstick and filler cap) for the sludge, indicating a more serious problem. Hopefully it won't be there. Also check your hoses. The cooling system is under pressure and a hose can have a split that may not be apparent when the car is cool or not running. Once pressure builds up the coolant is then forced out of the tiny hole by the pressure. I've had this happen. I found the leak by running the car till hot and then manually checking the hoses, squeezing as much as possible etc. Obviously, take care as it'll be hot.

[MiloAcclaim]

Hi all,

Thank You all for your comments and suggestions. I can still find no leaks, but it's not
losing water anymore.
Only one thing bothers me here and I think it might be the cause. As I have asked in the original post:

When I turn the A/C on, should BOTH fans (radiator fans) start up or only one?
At the moment I can see that when the A/C is on, only the left hand fan runs.

Thanks

Milo

[tk55]

i have a vt berlina 98 so it may not be the same. when the engine is cold, the fans don't turn on even when i switch on the air-con. then intermittently both will spin up for a second then off again. when engine is hot both will run full time until the temperature drops to certain level.

does the other fan ever turn on at all, when engine is hot?

[Craig54]

It was the water pump. The radiator guy pinted out white marks on the motor where it had been leaking.

[wortus]

As craig 54 says the coolant leaves a white residue where it leaks, my VN had minor leaks in the inlet manifold to head gaskets sometimes it used coolant then it would stop but it was not a lot so I never bothered to fix it, there would also sometimes be a residue on the top of the transmission bell housing and also coolant and oil sitting on top of the rear of the passenger side gasket.
If there is no trace of coolant leaking it may be the same gaskets but leaking into the inlet or exhaust ports. If the leaks are minor just go and get 3 cooling system pellets from Holden and stick them in I understand part of their function is to fix minor leaks.
I'd suggest degreasing the engine with kero, the alkaline types corrode the alloy and then check for any white residue or green water sitting on any parts of the engine. If the coolant is new it is easy to spot.

With the fans only one comes on with the AC.

[jeza91]

Mines being serviced as we speak, and was having the same issue.
Ill try explain it as best as he did.
Under the cover of the engine, where the 6 cylinders meet in a V, Oil and water flow through the engine, separated by a plate, and there was a break in the plate.
So the water was mixing with the oil, and disappearing very quickly.

[vtanthony]

just a another idea in the morning when its cold and u start up does it run rough then seem to settle after its warm .?

i had this problem and found it was spitting water out the exhaust manifold .i couldnt see that it was doing that cause i was in the car 5am in the morning turns out i had cracked heads but was stuck as to why i was using water and couldnt see any trace of leaks .

also tried all of the mentioned above even got the fans wired up so they would stay on constantly but the heads where cracke so it didnt do shit to stop the over heating cheers man i hope you find it soon cause i know how stressful it can be trying to find it