Hi!

If an XJR have the following codes

"ABS fault"
"Traction control fault"
"restricted performance fault"

Would I be able to take parts from an XJ8 and repair the XJR?



Thanks!

 

To get an accurate response to your tech question and the correct advice, please post the actual codes and the Model Years of the XJ8 and XJR.

Graham

 

The model year of the XJR is 2000 and the model year of the XJ8 is 1999.
Dont know the codes...

 

The only difference between the XJR and XJ8 is the grill, the XJR engine has a supercharger and the assoicated plumbing hardware, Mercedes transmission and larger exhaust tips.

Overall the cars are the same,

 

I would check your battery & alternator/charging system first-these cars are very sensitive to poor battery condition & can often throw up spurious fault codes due to low system voltage-especially when cranking a cold engine in cold weather with a tired old battery...

 

Differential ratio, suspension I believe

 

Differential the same, suspension is different.

The British didn't know how to build a sports car at the time of putting together the XJR. It should had a bigger intake and exhaust, differential should have been LSD with larger ratio gears and higher compression engine to help the supercharger perform it task. The suspension could have been a little stiffier, if not stiffier add larger front and rear sway bars. They did the look perfect, but the mechanical they failed at.

Put all of that in the XJR, you have a beast of a ride. Then you can truly say the XJR is totally different from the XJ8.

 

The ABS control modules are most likely different and probably will NOT interchange.
The U.S. spec cars are different so I would suspect that the ROW cars are also.
The X308 up to VIN F00034 have 5 pipe or 6 pipe (6 valve or 9 valve) modules.
JLM20555
JLM20556

From VIN F00035 the modules have 6 pipe (9 valve) modules.
JLM21323

bob gauff

 

Jaguar had a limited budget when developing the XJ8 & XJR. The standard differential was fitted to both types in order to rush the car into production so it could start earning money from sales.

The diff on the XJR should have been a stronger LSD unit, but it wasn't-for 'commercial' reasons as Jaguar was not exactly rolling in money at the time

Same goes for the supercharged engine-if they had a larger development budget then you would have seen over 400bhp & a higher compression ratio. They didn't have that budget luxury so did the best they could with what they had-Jaguar were owned by Ford, who were also in the middle of their own cash crisis situation.

The suspension is quite soft with high initial roll, but once it digs in it clings on doggedly. It's no track day car-buy a Caterham or Porsche if you want that

The earlier X300 6-cylinder supercharged XJR was more of a sports car with firmer suspension & the option of a manual gearbox. They have quite a cult following now, but the X308 XJR was aimed at a different target audience & is less overtly sporting.

Think of it as a comfy leather sofa with a rocket shoved on the back & you get the idea

 

 

Wrong. The differential is not the same. The XJ8 has 3.08
gears (rather fitting, wouldn't you say?), and the XJR has
3.06.

"The British didn't know how to build a sports car at the time of putting together the XJR"

I'm not even going to craft a response to that.

Anyway, there are a lot of threads that already exist
corvering this topic, the differences between the 2 cars.

1999 and 2000 were very different years for Jaguar,
a lot of changes were phased in during that MY shift.

I recommend a 1998-1999 donor.

 

The handbook for my 2001 XJR states that the same GKN 14HU differential is used on the 3.2L V8, 4.0L V8 & 4.0L V8 supercharged.

There have been several instances of differential failing on the XJR's because they did not fit an uprated unit & used the same unit as on the 3.2 & 4.0 normally-aspirated engines. It did not have a big overload margin when fitted to the supercharged XJR.

The ratios you quote of 3.06 & 3.08 are so close that they could have been due to mathematical roundup and wouldn't have made any difference on the road in actual acceleration terms.

 

Yes, 1998 MY is different than the 1999 My and so on, but the car has VERY little differences.

Have you seen the XJ8 Sport, it just a XJ8 with the cosmetics of the XJR.

 

the seat is different on XJR

 

The differences between 1999 2000 are big, different
steering wheel, different seats, different ASC system,
different stereo head, et cetera.

The XJ Sport is not an XJ8 with XJR visuals, it has the 98-99
Penta wheels, a slightly different rear suspension, with
a sway bar added. Also it had different seats, and colour
schemes. Also, all the dampers are different.