Driving with broken thermostat

As long as you won't overheat the car it's OK. Zee

The problem with this is that the engine will not get to normal operating temperature. This causes several things to happen. First the computer system does not go into closed loop where it is fully managinh the fuel system. It thinke the engine is cold and is similar to driving a carbureted vehicle with the choke applied, thus the engine is running rich. This can foul the spark plugs and cause damage to the catalytic converter system. Also the excess fuel can thin out the oil. Try to get this problem resolved as soon as possible.