2001 Vauxhall Corsa Oil and Tapping

Removed the oil cap this morning to find some white sludge under the cap. Not loads but I know its not a good sign. The car does get used on fairly longish journeys, 10-25 miles a day, and was last serviced in December 2007.

Also I have noticed that the car does not seem to idle all that well. Quite louder than normal quick, (in time with the idle), tapping noises.

Help and advice appreciated.

Thanks