Don't know - all was well until noticed LR Defender CSW starting to struggle. Can only drive in 4th or 5th gear and really struggles (with foot down flat on accelerator) if left in lower gear. Highest I can get is 55mphLearner drivers, lorries, milkfloats - all starting to pass me. Queues forming behind me in single lanes - not how it's suppossed to be.Complete novice and first problem we've had. Can see something dripping underside of engine - toward back. Can anyone advise?