I own a 2007 5 Series BMW diesel automatic. The car has a full service history, but is high mileage at 85,000. The DPF light came on and the message said that the car was safe to continue driving, however I may experience loss of power. I spoke to my local garage and did an internet search. The DPF light still came on saying safe to drive whilst I was looking into the options and then the power started to drop off.

There was no option but to replace the DPF, which is an expensive part. Despite a new DPF the car still lacked power and further investigation identified that the turbo had failed. The garage believes that the blocked DPF caused a back-pressure into the turbo causing it to seize. If this is possible then I am extremely disappointed that the warning light kept saying safe to drive when it blatantly wasn't (the gap between the light and the turbo failing was only just over a week). It transpires from my discussions including BMW that the DPF will need replacing anytime between 80,000 and 120,000 miles regardless of how it's driven and what fuel is used. I would be interested in your thoughts with regards to the DPF failure affecting the turbo.