hi again,i had another thread about how to change oil separator,thinking that this is the source of my problem:when i start engine everything is ok,rev ok...no strange noise,nothing.the problem comes when i start drive...when is in gear....1st 2nd,and any gear,car is working again normal,ONLY when i push clutch pedal,and the engine is in neutral,the rev goes up....example...if i drive with 2000prm,when i press clutch pedal,is going to 2500,3000....i know strange.i ve tried to clean throttle,nothing happened,reset the throttle sensor(took of battery)nothing hapened,look after air leaks,nothing.after all this things,i ve tooked my car to a service,there they put a diagnose tester(snap on)they tooked it for a drive test,and their answer was that car is working normal,and they think that ECU is changing something when i drive.they wasn t able to fix it.of course i was send to an electrician,or jag service.does somebody have any ideea what is wrong?....my car is a jag 2001 v6 3l petrol.hope i will find a better answer here then in service.cheers

Get an OBD tool with live data and check LTFTs engine hot, parked, at idle & 2500rpm and 99% you'll have an air leak.

Probably under the manifold, do some reading on where / how to fix etc on here.

i ve been to another service,and they had another opinion,they checked if is sucking air,and wasnt any problem with this,after another diagnose,the new guy sayd,that can be body throttle rev pedal or wirring....soo...i must wait and see what they will say next

Post #2. You're making life hard and maybe doing damage.

at this new service they finded that one off the throtlle body sensor(the sealed one) is damaged and is not making making connection betwen units...
next week we will see if this was the problem
jaguar s type 2001 v6 3l