Thanks guys appreciate the response. However i do not think sludge is the problem for the following reasons. Correct me if i am wrong.
My problem is this: I purchased a pre-reg e60 first reg in oct 2008, zero mileage when i bought it in june this year. Therefore i deduce that there is no issue as to running the engine on low oil. Suddenly a few days ago, a yellow symbol with a triangle in the middle appears next to the engine oil label on the idrive under the service requirements screen. then theres an indicator stating that servicing is due in another 600km. .
No reduction in engine oil as the engine oil status shows full bars . The manual is pretty useless as the only description given for the yellow symbol is that "service is required under the law" . When I sent my car to AB this morning the service advisor told me that it was due to the car being left stationary for too long and therefore the oil thickened. The SA used the word "thicken" . I found that a bit dubious but before i kick up some dust i would like to get my facts right.
So all sifus out there , i would really appreciate further deliberation on this issue whicjh i believe would be helpful to other e60 owners