I just put a deposit down on a car. The seller says it has a water leak "due to a compressed water supply" which to me sounds like maybe a damaged pipe constricting the water flow. However, a friend has just informed me that the seller could be trying to cover up that the head gasket has gone.

If it turns out that the head gasket has gone, and the seller has tried to pass it off as just a water leak to get rid of the car, do I have any rights? It doesn't mention anything about head gaskets, over heating etc in the advert and I put a deposit down purely on the basis that I believed it was just an issue with one of the pipes.