Oil changes - quality of main dealer servicing
I own a 2007 A8 3.0 TDI, which I cherish. It is main dealer serviced (variable) and I have never added a drop of additional oil. I have noticed that the dipstick indicates it is usually overfilled (ie above the "max" indicator); and the oil is very black even though it is only about 6,000 miles since the last service. I am a little worried that the main dealer may be overfilling and/or may not be doing the oil change properly (eg not replacing the filter). In the old days, overfilling was harmful but I have no idea whether the colour should be black given this type of engine. I am going to come off the variable servicing regime so that the oil can be changed more quickly but am I being paranoid?
Diesel engines deposit a lot of carbon in their combustion chambers and this soon turns fresh oil black. Not when the engine is new, but once the engine has done some work.
Answered by Honest John on