I was informed by a garage representative that our Volkswagen T5 Transporter van requires a new engine and turbo due to metal contamination in the oil (an unknown internal problem) and a new manifold due to a crack. This is from a main dealer so the price is high, but I agreed as long as I could have my old engine and turbo to find out why it failed so catastrophically. The new engine was fitted and the dealers informed us we could not have the old engine unless a £2500 surcharge is paid on top of the previously-agreed sum. He only just found out about this himself so he did not tell us. What can we do, and where do we stand legally? Can we ask to have engine removed and van returned as it was?