never had this before has anybody switched of there engine and fan stops on...............

come back from cambridge today a steady 60 up to 70 at most with wife and son and huge dog in back

just wondered why? fan would stop on at all when engine is off and keys in my pocket

Yes it does it every so often. Normaly its a dpf regen. They will stop after about 10/15min.

Perfectly normal

YES its normal for Diesel, the DPF get extra hot while regenerating

I had the same concerns with my 1st Diesel 3 years ago 1.6 Ford focus TDCi ,

you will get used to it, don't worry