I am writing you regarding my Ford Focus 1.6TDCI. I purchased it in April 2012 with 38,000 miles on the clock. In October the engine malfunction light came on. I took it into the Ford garage we purchased it from. They took it for a run and cleared the filter and code under warranty. On their advice we put in premium diesel and took the car for a long run each week to keep it clear. On 7 December, travelling along at 85mph on a long straight road, the engine malfunction light again came on. The garage again connected its computer and diagnosed a DPF fault but failed to check anything else. They then took it for a drive to clear the filter, where the engine had a sudden surge of power, stalled and failed to re-start.

When they checked the oil there was three inches too much oil in the sump, the injectors had melted and the turbo had blown. An independent diesel mechanic has confirmed up to £4000 worth of damage to a car I purchased for £8000 eight months ago. I was wondering if you had any advice. Did the DPF cause all the other problems? As the original fault with the DPF occurred whilst under warranty does that mean they failed to fix it the first time? Also, as their mechanic was driving it at the time of all the other faults, does that mean he's liable?