These are classic symptoms of failure of the limit switch or mechanical parts within the mirror. There are several threads here about power fold mirrors. Also check other BMW forums. BMW does not sell the motor, limit switches, or little gears. However, since it has been such an issue, you can find aftermarket parts on eBay. Also search eBay uk.

Check the alignment pins for the switch aren't broken off. I had to rig mine to keep it in place. Even with its pins it liked to jump out of place. Also check the little alignment pins on the gear housing are in place.

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David.X5
2001 X5 4.4i Sport
SOLD! at 160k miles