We have a Mk4 Focus with the 2.0 EcoBlue engine and the behavior of the cooling system seems pretty odd.  It takes forever to come up to temperature from cold ( probably 15km open road ) and when it finally does it behaves like it's too hot.  The gauge will show just below the mid point but the fans will be going full blast and if you stop it the fans will continue for another 15-20 minutes.  There's no obvious sign that it's overheating, the coolant level in the expansion tank is normal and not pushing coolant out but the fan control seems to be behaving like it's too hot. 

Our older Mk 2 focus did this once when the thermostat housing had failed so that was obvious and understandable plus the gauge showed it was getting hot.  I guess wouldn't expect the fans to continuing running after engine off unless the cooling system had a problem.  Is it likely that the ecu uses a different temp sensor to the gauge that might be faulty?

Normal for the car to take 15km to warm up.

Only time I have the fans stay on is when the car has been doing a dpf regeneration. 

 

Is there anyway to tell whether it's doing dpf regeneration?

11 hours ago, SamB7 said:

We have a Mk4 Focus with the 2.0 EcoBlue engine

Does your profile need updated  ?

According to my local ford dealer this issue is being caused by a faulty actuator.  Apparently they have slats that control the air flow through the front of the car, closed when cold to improve warmup and then they open once the car is up to temp.  On my car they're partly open and not moving.  It's getting some airflow when cold, making it take longer to warmup, but insufficient air flow when warm therefore triggering the fans to run. 

9 hours ago, SamB7 said:

According to my local ford dealer this issue is being caused by a faulty actuator.  Apparently they have slats that control the air flow through the front of the car, closed when cold to improve warmup and then they open once the car is up to temp.  On my car they're partly open and not moving.  It's getting some airflow when cold, making it take longer to warmup, but insufficient air flow when warm therefore triggering the fans to run. 

These are generally called an active grille shutter.  They're fitted to many Focus's of that age so should be easy enough to source a good used part rather than having to pay Ford prices for brand new.