Sorry, forgot to say it smokes mainly under hard acceleration but doesn't need much to make it do it. My wife drove round a local car park at a fairly steady speed so that I could watch the back.

Thanks - Air filter was changed about 6 weeks ago, done 200/300 miles since. Could it be anything to do with fuel injectors, one was changed at that time ?

My 2003 diesel is producing black smoke on acceleration although seems to be running ok. Diagnostics appear to show no fault. any ideas please ?

Could be the effect of heat on the volumetric sensor but I have had the car into my local main dealer on three occasions to investigate this fault and they didn't come up with this. On the other hand they didn't manage ti correct the problem either so what do they know ? Someone else suggested...

Thanks for your response Wills. Message centre just shows usual time and date. Do I need to search for message re alarm ?

Whenever the car is parked in the sun - often no option - I spend much time in Spain - the alarm activates - every time. Is this common ? Any ideas to cure ? Can it be disconnected ?