The oil level in our 1992 544 Hymer Fiat 2.5 Diesel is increasing after a recent oil and filter change. I can only assume that it must be diesel entering the sump via a leak in the injector system. It is only a guess so am asking if anyone else has had a problem like this. Also, can anyone recommend a diesel specialist. We live in North Hertfordshire but would travel if positive experience has been found by any Motorhomefun members. The vehicle performs brilliantly by the way. Good starter, economical no other indications of problems but I can't ignore this.