Creamy gunk in water resevior

[rav]

Thanks for your reply. Something else I forgot to mention, the oil level on the dipstick is reading normal i.e not loosing any oil. So where do you think this oil is coming from? If oil was going from the engine block to the coolant, wouldn't the engine oil level drop?

When I say that the resevoir had gunk in it, I mean it was really thick gunk. It looks like a very thick cream rather than water.

I've booked it in with my local porsche garage next week and maybe they can shed some light on it. But even they suggested flushing out the coolant system and re-filling. Think I will give that a try.

Thanks for your advice