I just purchased a 2007 XKR Convertible to replace my ‘95 XJS and my 2017 F-Type S couple. I am learning its personality.

There is a compressor type sound, much like an air driven lumbar support compressor intermittently present behind the drivers seat below the drivers side rear window. It seems to go away after 10-15 minutes of driving.

Anybody tell me what it is?

As it is a 27,000 mile car and in pristine condition, I don’t want to disassemble interior panels to determine what it is.

 

Your active exhaust valves are vacuum controlled and the vacuum pump is located sort of above and behind the left rear wheel well.
The sound is probably the pump evacuating the small reservoir tank associated with it.

 

Thank you for the quick reply. The vacuum pump makes sense.

I had a friend step on this kitty’s tail (petrol pedal) while I sat in the “back seat” and found it would run for a second/second and half when he stepped on the throttle. Every time.

Is it normal to be audible enough to be distracting, or is it telling me that the vacuum pump needs to be replaced?

 

Sorry, I can’t answer that, as I don’t have an ‘R’.
Maybe someone will chime in about ability to hear that pump.