My car had no warning lights and the temperature needle was dead on 12 o'clock.
It just felt a little sluggish.
I connected my c110 scanner and had these faults:

From the net I enabled the hidden computer to view my temps and even though the needle was right my car never went above 78c.
I was advised on another site that I should change my thermostats. After getting a ridiculous quote from bmw of £500+ I tried a couple of specialists who quoted £260-£285.
To change thermostats I thought that was excessive so I bought a new egr stat, main stat and 3l of bmw coolant for just under £120 (from bmw).
I then fitted the EGR stat as that was a quick and easy one (15-20 mins) and went for a drive. The car was better as it now reached 79-83c but when heating was on it dropped to around 75c.
Yesterday I tackled the main stat and it was done in under 2 hours and the car now reached 86-89c but my c110 scanner still had the faults with the DPF.
Again another site recommended I drive with the c110 scanner connected and keep resetting the error codes until it forced a regeneration. This took around 30 minutes and now the car is perfect and fuel consumption has definitely improved.
HTH