Hi , just aquired an 850 S.E. 1997 model 2 litre. Seems fine but not long after starting off, within 2 miles there is often a single loud "crack" sound, just the same as that made by the impact of a stone on a windscreen, but without the stone. Steering seems o.k. wonder if it is anything to worry about? ps sound seems located in vicinity of the steering column.