Advice on 1999 Q45t

[Bin_jammin]

If it were my car (or going to be my car) I'd have the oil analyzed, along with all the other fluids. Basically, you send in a small sample of each fluid, and they'll tell you all about it. What type of materials are floating around, because different parts are made from different metals (bearings, cylinders, rings...) they can detect hydrocarbons, antifreeze... usually not more than $50 per sample, from what I can recall, but don't hold me to that number. And no, I have no affiliation to these people, it's just good practice! check these people for example:http://www.herguth.com/testing/sampling.htm