4 weeks ago I took the car to my local garage as the engine was making a rattling sound from point of ignition to around 30mph (where it either stopped or was just drowned out).

After coming to the conclusion that sound was coming from the cylinder head (after initially suspecting dephaser pulley/ cam belt), the cylinder head was opened and revealed that there was substantial scoring/ grinding to the cam shaft. Was told that the damage was sufficient enough to warrant a whole new cylinder head.

The work was done along with a new water pump/ cam belt etc.

I picked the car up after the repair and immediately noted that there was a significant juddering while the car was idle (as soon as you accelerate it goes away). I told the garage and was advised that this was probably due to the new parts "settling in".

A week later, the problem still persists so I returned to the garage. They couldn't find what was causing the problem but told me to continue to drive the car over the weekend and bring it back on Monday.

They now think that it might possibly by the dephaser pulley!!

After shelling out nearly £2000 for the initial work, I don't really want to be forking out another £300 + for the pulley to be changed.

As the car was taken in with one problem but left with another, should I be demanding that any work to fix this second problem be done free of charge?

Any advice gratefully received!