1997 Australian Jaguar XK8
Hi all,
My jaguar is running well at 110,000 km.
I believe it had substantial transmission work carried out before I purchased it.
It does have an annoying problem.
The transmission appears to be working perfectly in normal driving however if you use the manual selection mode around the J gate it almost immediately displays the transmission fault light. It doesn't matter whether the car is moving or not. . If the engine is stopped and restarted the light dissappears and the transmission returns to normal I imagine it must be a simple problem in as much as it has nothing to do with torque being transferred through the box. Could it be a linkage problem?
If anyone has any thoughts or experience with this problem I would be very keen to hear from them.
Kind regards and season's greetings to all
Al

 

There are a couple of micro switches located in the J gate that would be a great place to start looking. They could have been disturbed or maladjusted during the transmission service you mentioned.

 

1+ I have the same problem, but haven't fooled with it yet. Either microswitches or cable adjust. The switches have to agree with the position of the rotary switch on the side of the transmission, otherwise it gives an error message. I can't go from "4" to "D" without the fault popping up.

 

It certainly sounds like we have the same problem
Over Xmas rather than take the xk8 for a 1000 km round trip over the mountains to visit relatives we took my MGB. Actually what a relief to drive a sports car with no micro switches, micro processes and micro managers ( limp home mode etc).
It performed beautifully. Sometimes I wonder about progress.
Thanks for your input
Al

 

But you took Lucus, the Prince of Darkness, with you.

 

When you shift from D to 4 you are NOT moving the selector cable so the gearbox needs to know ELECTRICALLY that you selected 4.

This is done with a cam plate and microswitch.

You either have a broken cam plate or a faulty or disconnected microswitch in the selector lever illumination module.

bob gauff

 

A common problem on XK8s is the Rotary Switch on the side of the gearbox, basically when this fails the gearbox looses which gear it is in and goes straight into gearbox fault and then you are stuck in 3rd gear.

Cheap enough secondhand, you should get a code to pull off to confirm

 

Certainly Lucas did make some terrible junk (though I suppose it must be the car manufacturers who were ultimately responsible for either specifying junk or accepting junk) and Lucas probably contributed as much to the demise of the British motor industry as any other factor.
Having said that, I haven't had too bad a run from Lucas on older pommie cars and bikes and I guess that having mucked around with the MG for so long that most of its weaknesses are ironed out.
It's the smug reduced performance light on the XK maliciously coming on when you least expect it that rattles me
I find the issues with the 8 double frustrating as our 97 x300 with 340,000km has virtually never put a foot wrong and when a rear wheel bearing did fail at least I could comprehend it (and fix it).
Kind regards to all
Al