You may have seen about a month and a half ago the crank pulley went on my 2.2DTI , phoned the AA and got recovered to a local garage my family has used for years. Was asked to pop in with the £200 pound for the pulley and £60 for a tensioner.
All happy went to collect the car and when i started it up i thought i could hear a slight vibration / knocking , however it was a tiny sound so thought it must be my mind playing tricks , along the road however whilst holding the clutch at the traffic lights it again started vibrating knocking but louder however no strange sounds when driving.
Took the car back nothing wrong im just hearing things , so anyway after taking to a number of garages and even having a dealership have a look no one could find the problem.
So whilst my dad was buying his vectra SRI i quizzed the service manager who said it had to be the pulley and what do you know theres an aftermarket part thats not doing the job.
Now as i have seen on here a few threads in the past where people have had this problem and not had it answered i believe you could be running with a sub standard aftermarket pulley.
Part number for a genuine Vauxhall pulley for the 2.2DTI is 55351711 £165.00 plus VAT