My 2001 Jaguar XJ8 Vanden Plas has suddenly started running terrible. Car has only 67k miles and was running perfect except for occasional hard starting when hot (think the fuel pump might be going).
Lent my car to a family member who said the coolant overflow hose had broken and allowed coolant to leak out. He said he found the problem before the temp got hot and shut off the engine but now the car is running very rough and check engine light is on, also message reads "restricted performance". The only codes showing are p0327 and p0332 which relate to the 2 knock sensors. My question is could both of the knock sensors have gone bad overnight? and would they be causing the engine misfiring? My guess is that the car got hotter than I am being told. I am wondering if the head might be warped or a head gasket blown. Anybody have any thoughts?

 

Maybe they never saw the temp "gauge" go up, since it really is not a gauge, but more an idiot light with a needle (you won't see it move to the hot section until it is too late. I would suspect it did overheat though....

 

Melting the knock sensors is a common result of overheating.