Hi folks! Im just about to do a bigger service on my 1.5 MB9. However, due to (oil sump is a bit "oily" wet) broken oil sump seal, Im now running on minimum (low dipstick hole still covered with oil though). Sad fact is, I still have to use the car for next 7 days before the service and unfortunatelly I dont know which oil is there in the engine (I know its Pennzoil, but thats it - Im a new owner). Now, I would like to either: a) top up oil - but dont know which one can I take do an oil and non-OE filter change (cheap solution - should do for a week). But again, which oil to use? Im leaning towards option but I have been told two different things. Friends advised me on using high detergent oil so I flush out all the dirt out before using the right, new oil. Some, on the other hand, told that wouldnt be a good idea because if I cleaned all the carbon build-up in the engine, that might result in rings losing tension. Consequentially, engine would be inclined to start burning oil and suffer from blow-by. What would your advice be? Btw, its a 98 reg. 1.5 84 Kw engine - 120K miles on the clock... Many thanx!