I have a 95 xjs. Just noticed a click sound from the passenger side dash when I push on the brake peddle whilst in reverse/neutral/drive.
When in Park there is a much louder click that seems to come from on top of the transmission. In fact I can feel the knock just in front of the gear shift lever. I have checked the brake lights and they are fine.
Any help in explaining what is going on most welcome.
Nick.

 

I have taken the wood out that is around the gear shift and discovered a solenoid. When pressing the brake whilst in park the arm of the solenoid moves in. There is a lever at the end of the arm, it is this lever that is making the knocking sound. part # of the solenoid is. Lucus DBC 11071. No idea as to what it is supposed to do. Shall investigate further.
Nick

 

All modern cars have this. It's a 'safety' feature to prevent the transmission lever being moved out of park without the brake pedal being pressed.

 

Thanks Mikey.
I found out that the lever at the end of the arm is making contact with the plastic trim housing around the gear shift lever. I will get the Dremmel out, and remove the contact point and add some sound proofing to the area.
Nick