It didn't help the running of his diesel X-type...
A couple of days after the Terraclean he found the oil level in the sump rising - seals on the hi pressure fuel pump (OK, a not unknown problem, but it was OK leading up to the Terraclean) so fuel now getting into the sump.
I just don't trust these supposed 'miracle' cures... If this is supposed to remove the gradual build up of combustion material that material still has to go somewhere - if it breaks up then expect damage to valves and valve gear, &c. particularly the way they rev. an unloaded engine...
