Dear All,
Greetings

I have a 2008 x-type currently at 115,000 Km (71457 miles) . I started facing a problem since a while is that when I reduce speed then push again on the gas pedal the car starts shacking violently and do not accelerate . Same issue happens when I try to exceed the speed of 120 KM/h (75 m/h)

The mechanics checked it and suspected that it is the URL pump who is not delivering the needed amount of gas , but after changing the fuel pump the problem remained . Surprisingly I was discussing its someone about this issue and he had faced the same problem with his jag last year and the problem as he described ( we are both not professional mechanics) that is is a switch in the gear related to electricity which failed and should be changed then programmed.

He changed tat at the Jag dealer however the cost was huge and hence I am seeking your advise if anyone has any idea about this problem

Thanks

 

Does the check engine flash? Any codes?

 

Nothing at all, will just feel it when exceeding 120 KM , it starts to shake violently and has no other choice then reducing immediately

 

fadixx7, I'm having that same problem as well. But I get it only at prolong speeds of >135km/h. What switch in the gearbox did your friend change?

 

Anyone else with similar issues?

 

iawgnix, from the sounds of things, it almost sounds like the car is going into limp mode. I want you to try something for me. Get the car out on a lonely road and shift the J-gate into "2" and then press on the gas to make the car accelerate until the engine RPMs get up to 4,000 RPM (or as high as they will go, whichever is less). Did the car start shaking again at a speed other than 75 MPH? If yes, then this confirms the car went into limp mode and it is attempting to limit the engine RPM to protect the engine.

Beyond that, not sure what is going on. THis is something new that i am not familiar with and without getting my hands on the car, hard to say what is going on.

 

My car shakes badly and stepping on the gas has no effect at all - i don't get any warnings on my dashboard though. What are other signs that the car is going into limp mode?

I don't think its the engine limiting the RPM thou. I have launched the car a couple of times and seen the rev almost touching the 6500RPM mark. (This was on Premium Gasoline).

Thanks Thermo, you've been a great help around here.

 

iawgnix, if you can rev the engine up to 6500 RPM (above 3,000) then the car is not going into limp mode.

The other thing you can check is when the car starts to shake, you can keep applying the gas and then also apply a little bit of brake (depress the gas pedal harder to attempt to maintain speed, obviously doing so in a safe manner). Does the shaking go away? If yes, then your problem lies in the torque converter. By applying the brake, this causes the torque converter to unlock and will allow the engine to rev up some and in some cases, if the torque converter is unsure of what to do, it will engage and disengage rapidly, leading to the shaking.

After this, I would say you need to see a mechanic and see what they say. They will have a computer that will be able to see what the car is doing and be able to diagnose it in very little time.