I have a 2002 3.0i petrol X5 (MANUAL) 45000 miles which has suffered a catostrophic engine failure.

School run after cold night , 20mph, no warnings/symptoms, sudden billowing white smoke from rear and 'burning smell.
Main dealer says engine completely goosed - spark plugs removed and unable to do full revolution manually.

Other X5 websites suggest possible 'oil separator' failure. Bmw says does not exist on petrol version.

Offered Bmw re con engine for £7k fitted, after which car worth £8k trade in!

Any thoughts please - gutted!!