Hi i wonder if any one can help i changed spark plugs on my jaguar x type 2.1 v6 2003 and after 2-3000 miles it will jolt when pulling off slowing down in a gear and accelarating cant work it out i have changed spark plugs 3 times and when they are first changed the car runs really good but after the above mileage is covered the car starts to play up . The spark plugs are the correct ones for the car and there is no vacuum leak had it checked by garage even he is puzzled has anyone had this problem before it sometimes takes a couple of turns on the key to start but not very often .

Hi Deane,

 

I am a bit mystified and you have done the obvious thing.  

 

I think it could be something else electrical rather than mechanical.

 

Good Luck,

 

Peter.

I was thinking the same any ideas .

Hi Deane,

 

I am no expert but I would look at plug leads and possibly the timing.

 

I used to be able to sort things like that out on my 1962 Triumph Herald, and My A40.  These modern cars are a bit more complicated.

 

Regards,

 

Peter.

hi don't know to much about petrol cars but could it be the coil pack. its just someone I know with a saab had the same thing was the coil pack

Hi Deane ...I would go with Peter on this and say perhaps ..Plug Leads.???

 

Frank

Trevor points to the coil pack, Deane, and that also is a possibility.  I had a power loss on my Rover Sterling V6 petrol  and one of the coils on the pack was duff.

 

Peter.

thanks for replys i will go to garage today hopefully sort it .