Blue Print has issued a Protip which shows how it has improved the design of a commonly used water pump application to solve a common coolant temperature malfunction. 

The improved water pump is ADC49169, fits various Citroen, DS, Fiat, Ford, Jaguar, Land Rover, Mitsubishi, Opel, Peugeot, Toyota and Vauxhall models. 

The problem means engine coolant temperature and engine management warning lamps become illuminated. The fault code ‘P0115 coolant temperature malfunction’ is present in the engine ECU. 

The cause is that the original water pump impeller is made from plastic, which can become detached from the impeller shaft. Therefore, the water pump is turning with no effect and no coolant will flow around the cooling circuit of the engine. 

Blue Print recommends that a technician ensure the engine is cool and removes the coolant filler cap. They should then remove the upper hose to the coolant expansion bottle and hold this over a suitable receptacle, before starting the engine. With the engine at idle, there should be a small trickle of coolant flowing. The flow should increase as the engine speed increases. If there is no coolant flow, this would suggest the water pump impeller is not turning. 

To replace, remove the auxiliary belt and timing belt. Replace the defective water pump with Blue Print water pump ADC49169, which has an improved water pump design with a metal impeller. This eliminates the potential failure caused by the water pump fitted with a plastic impeller. 

When replacing the faulty water pump, Blue Print recommends that the timing belt kit and auxiliary drive belt is also replaced at the same time to ensure the reliability of the engine. 

The cooling system should then be filled with fresh coolant, then technician should vacuum bleed the system to expel all air from it. To ensure the cooling system is working correctly, start the engine and recheck the flow of the coolant to the expansion bottle. Reset any fault codes stored in the engine ECU.

To view a full application list for the ADC49169 water pump go to the partsfinder online catalogue here. 

To view the original Blue Print Protip please click here.