losing water

[snake0180]

i have a e34 520i v12 straight 6 bmw
after 30-50 miles i lose about 500ml of water.i have fitted a new thermostat and a new viscous fan{both were faulty}now the temp don't go above the quarter before the fan cuts in.there is no visable leak inside or out.it is parked undercover and everything is bone dry.the oil is clear of water on the dipstick and cap.doe's anybody have any idea's where the water's going.

[witeshark]

You may have to pressure test the cooling system to find the leak. Welcome!

[snake0180]

Originally Posted by witeshark

You may have to pressure test the cooling system to find the leak. Welcome!

i forgot to mention it has already been pressure tested and no loss of pressure or water

[witeshark]

Do you have any reason to suspect a small head gasket leak?

[snake0180]

Originally Posted by witeshark

Do you have any reason to suspect a small head gasket leak?

there's no water in the oil.i would of thought if it was the head gasket it would have lost pressure on the pressure test

[witeshark]

Maybe there's an issue with the expansion reserve tank in the engine bay.

[snake0180]

Originally Posted by witeshark

Maybe there's an issue with the expansion reserve tank in the engine bay.

i did another pressure test but left it a lot longer and it dropped slightly but still no sign of water anywhere.so i bought some k-seal which is a coolant leak repair,which repairs:head gaskets,blocks,anything metal.it works with antifreeze so theres no messing about draining the system.just pour it in and go,it worked a treat,no more leak.yippee.

[witeshark]

Very cool!