Parts specialist First Line has issued some useful practical advice to technicians on the fast growing issue of electric water pump replacement.

Garages are starting to see an increase of Electric Water Pump replacements, as the popularity of using auxiliary and secondary electric pumps grows amongst vehicle manufacturers. First Line point out that modern, low-emission, high-output engines are designed to run within a very small temperature window in order to maintain optimum efficiency. This is controlled through the Electric Water Pump, which regulates the coolant flow dictated by the electronic control unit. When it comes to forced induction engines, additional cooling of the turbo/supercharger after the engine is shutdown is required in order to prevent premature wear, particularly to the turbo bearing.

First Line has gathered considerable market intelligence on many of the issues that can cause problems with the Electric Water Pump, and can advise on successful replacement.

For example, the N51, N52, N53, N54, N55 and N63 engines in several BMW models have a tendency to experience water pump failure from as early as 60,000 miles, which is often related to the electric motor in the pump not running at the correct speed and eventually stopping. This potential failure should be detected by the primary vehicle control module during its system scan. However, if undetected, the only warning to the driver will be the yellow dashboard light illuminating, followed shortly by a red light, indicating the engine overheating.

Some VW T4 drivers have complained that the water pump continues to run long after the engine has been switched off, running down the battery. In this instance, First Line recommend checking the coolant temperature sensor, which could have failed and locked open, causing the pump to operate continuously.

Range Rover also have an inherent problem, which is experienced on the Range Rover III/IV and Range Rover Sport I, were during the vehicles production, the Electric Water Pump connector may have been wired incorrectly. As a result, the auxiliary coolant pump that cools the supercharger runs backwards. This will cause the pump to fail prematurely, so when identifying the cause of the original failure, it’s worth checking the connector is wired correctly to avoid further problems.

First Line says it is also important to note, that when carrying out any water pump repairs, it is imperative that the old coolant is thoroughly flushed through and the system refilled with fresh coolant of the correct specification.

First Line offers a comprehensive range of replacement pumps covering a multitude of references with every product coming with a 24-month/24,000 mile warranty. These are available from stockist nationwide.