Only one or two trips to make up the 200 miles travelled and a shielded air filter - all very puzzling. I don't see how a small percentage of oil missed in the draining procedure could contaminate the whole system so quickly. Proper analysis of % water content would have been interesting but it's too late now.
We overcame the problem by using flushing oil twice to get the muck out and fitting a new oil filter. It will be interesting to see if it happens again.
Thanks for your comments,
Phil
