@Racer
I had problem with the Heater as my Mechanic took out the thermostat valve few months back “Saab Thandi chali gae” . I told him what he did was wrong as diesel engine performs better above 40 C.
Now some places it was so cold had to drive in 2nd gear for the Temp to rise, also drained 30% water from the radiator, but still it did not cross 40… so no heating available 
After draining 30% water our Room Temp was pleasent
