under hard acceleration or when i lift my foot off the gas and immediatly put it back on i find i get what can be described as a ringing or rattling sound come from the the engine. this same problem occurred in my last 2000w jagaurxj8. i never found out what it was. could somebody please help me with this. i only bought the car in april of last year so i have 2 months of warranty left and i would rather the dealer sorted this out under warranty. also on auto setting for headlamps in rainy weather they flicker off and on. the dealer has changed the sensor but the same thing still happens. could someone please advise me on this. thank you

 

Your first scenario sounds like you are describing 'pinging' or 'knock', caused by fuel trims not being able to to be corrected by the variable valve timing units. It could also be use of too low of a fuel octane being burned, or mixture too lean to get adequate combustion results.

 

Any problems at night ? Do the headlamps flicker at all at night and on Auto or Headlights On settings ? I had flickering of both LH and RH lights and a new multi-switch on the steering binnacle cured it