I bought a 2002 A4 with 58k from KG Suzuki. Since the first day I picked it up I have been running full mobil 1 synthetic and replacing it every 6000 miles. I was driving on a weekend vacation less than a year later and my oil light came on. I checked the oil and it was full. The next day I got an oil change just in case. I didnt know the oil change history from the previous owner. Well the oil light wuoldnt go away so I took it to the dealer. They said I have sludge and needed a new oil pick up tube. Which I paid for. Not knowing the history... read full review »