Running problem on E39 1997 97K

[ginis50]

1997 E39 95k runs a treat when cold and warming up. After driving for a time
the engine blips and cuts out for a second. It catches again but will then run on 5 cylinders causing loss of power etc. I assume it is the same cylinder each time that I am losing. This fault occurs at random driving distances from cold. 5,10 or sometimes 50 miles or more. To correct it I have to stop the car, turn of the ignition and then restart. I then have 6 cylinders back and the car running smoothly. If the engine blips when at tickover it cuts out but is fine on re-start. This annoying fault can occur several times with increasing frequency on a long journey. Any ideas all you BMW experts out there?

[sidewinder69]

Fault in the spark plug/ plug wire...faulty O2 sensor...faulty fuel injector...spark plug wires crossed at the distributor cap...faulty ecu.

Your HUD come up with any warnings when this happens or when you shut it off? Like a "check control" warning?

My E34 does the same blip and catch, but I've never gone down a cylinder because of it.