I have lately acquired a 2000 P38 diesel, it's done a fair few miles but is generally very clean and was pleasingly inexpensive. It has behaved very well, both around town and on the motorway, but in the last few days has shown some inconsistent behaviour in the automatice gearbox. It is sometimes very reluctant to move up into top gear and one one occasion barely got out of second and over 30mph in a 10 mile journey. My immediate thoughts are an oil change or at least a level check and top up, does anyone have any experiences that might suggest this is a more fundamental, and expensive, problem?