Yup, Simon unfortunately where an engine has a serious problem it can make other issues difficult to find as the initial problem will cover up other symptoms. Happened to me once with a Td5 which came in undriveable with a blown head gasket. Fitted a head as it was beyond repair only to find the block was porous and leaked coolant into the sump/ hydraulic locked it one morning. A difficult situation indeed but worked out OK in the end. Did a fair bit of labour $ on that job, but these things happen from time to time:(
JC

