One problem related to engine overheat has been reported for the 2013 BMW X3. The most recently reported issues are listed below.
Engine coolant pump and thermostat failed at 52000 miles. It's 2000 miles after the warranty expired. It was failed way too early by any measure for any on road vehicle. I had engine overheat warning, possibly due to coolant pump failure. However, the oil temperature gauge on the dash showed normal temperature. After vehicle stopped, tried to inspect the vehicle with hood opened. With oil temperature gauge saying normal temperature, coolant was over heating, which could cause the injury from confusion. One temperature gauge saying normal while the coolant was over heating. BMW should address this issue on their own. They ignore this problem and passes to customers. This should be seriously considered for recall.