BMW cars (model year 2006 or later) equipped with the N51, N52 & N54 (New generation 6 cylinder) engines have electric coolant pumps that are failing with as little as 45,000 miles on the clock.
With the absence of a temperature gauge on these later model vehicles, the attentive driver has no idea until up to the point that the vehicle is overheating by way of:
1st – the enormous loud engine coolant fan running at max speed and
2nd – an urgent message on the information display to immediately stop the engine!
If you don’t turn it off within a few minutes – the motor shuts down and stops wherever you may be!
In some instances, a momentary failure of the pump will store a “coolant pump speed deviation” code in the diagnostic memory of the DME (engine control unit) which can be read-out and thus used to forewarn the driver that the coolant pump is failing.
We’ve included this simple scan of the DME as a regular procedure in any maintenance or repair work we do on vehicles fitted with an electric BMW coolant pump.