brown liquid

[robotype]

back from the week-end trip about 200 km on the highway when I arrived home I heard liquid dripping from the engine, further inspection result in a leak under the intake:

<img src="http://img340.imageshack.us/img340/3548/leakx.jpg">

after I stop the engine it kept spitting from the leak for 10 minutes infact 1.5 liters of water was missing but what worries me the most is the color of what came out:

<img src="http://img683.imageshack.us/img683/4729/horribleliquid.jpg">

but the water in the reservoir is clear though...

<img src="http://img704.imageshack.us/img704/4503/reservoir.jpg">

what next?