W140 massaging seats
 

Not sure if this is or was an option but on my 97 S500 the driver and passenger front seats (lumbar) go through some sort of inflation and deflation sequence in a simultaneous fashion.

It is sorta creeping my old lady out so I told her I'd try and see if anyone here on the board might know how to fix it.

thanks and yes I've been gone from here for some time I must admit.

Most likely an issue with the vacuum control switch OR a leak in the system.

Thanks M.B. Doc. I need to start digging around and see what I can find.

Where is the vacuum sourced from, would it also affect any other systems? As far as I know everything else works fine like the central locking system.