Creamy gunk in water resevior

[rav]

Hi Peeps

Noticed the other day some yellowish coloured water on the drive way where my boxter was parked. It made me a bit suspicious so I went into the boot of the car and took off the cap from the water resevoir.

I was horrified at what I saw......the water resevior was full of creamy stuff (like oil n water mix)!!!. The wierd thing is, the car didn't overheat or anything so I'm ruling out head gasket because I also checked the oil cap and that was clear except for a bit of condensation on it.

Any ideas on what this maybe? Could someone have put oil into the water resevior by mistake? Some other mechanical problem? I've checked the dip stick too but no creamy residue on this what so ever. This creamy stuff appears to be inside the water works of the car.

Please help as I haven't driven the car since this discovery :-(

Many Thanks
Rav