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Estimates last updated October 16, 2025

BMW 645Ci Water Pump Replacement Cost

The average cost for a BMW 645Ci Water Pump Replacement is between $884 and $1,274.

Labor costs are estimated between $366 and $537 while parts are priced between $518 and $737.
This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.

For a more accurate estimate based on your location, use our Fair Price Estimator below.

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Get a fair price estimate on BMW 645Ci Water Pump Replacement in your area - honored at RepairPal Certified locations.

Water Pump Replacement

What is a water pump?

The water pump circulates coolant through the engine's cooling system to help prevent the engine from overheating.

How does the water pump work?

The water pump is driven by an accessory belt at the front of the engine, or by the timing belt or timing chain. As the engine runs, this belt turns and keeps the pump working.

What are the symptoms related to a bad water pump?

The two most common signs of a bad pump are leaks and noises. Leaking water pumps can result in damage to the drive and timing belts, and cause the engine to overheat. A failed water pump can be caused by other problems in the cooling system, such as a bad thermostat, radiator or head gasket.

Can I drive with a water pump problem?

If the water pump is not maintaining good coolant circulation, the engine will overheat, causing leaks, possible head gasket damage and ultimately a failed motor. If your car begins to overheat, pull off the road and shut the engine off as quickly as you safely can. You will have to have your car towed to a repair shop.

How often do water pumps need to be replaced?

This depends on the model of car and its driving conditions. The water pump does not wear like a tire or a ball joint, but eventually the bearing or impeller can fail inside the pump.

How are water pump issues diagnosed?

BMW 645Ci Water Pump Replacement Cost by Year

The average cost for a BMW 645Ci Water Pump Replacement is between $884 and $1,274 but can vary from car to car.

BMW Water Pump Replacement Cost Estimates

The average cost for a Water Pump Replacement is between $884 and $1,274 but can vary from car to car.

Quality Car Repair.
Fair Prices.

Get a fair price estimate on BMW 645Ci Water Pump Replacement in your area - honored at RepairPal Certified locations.

BMW 645Ci Water Pump Replacement Cost by Year

The average cost for a BMW 645Ci Water Pump Replacement is between $884 and $1,274 but can vary from car to car.

Water Pump Replacement

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What is a water pump?

The water pump circulates coolant through the engine's cooling system to help prevent the engine from overheating.

How does the water pump work?

The water pump is driven by an accessory belt at the front of the engine, or by the timing belt or timing chain. As the engine runs, this belt turns and keeps the pump working.

What are the symptoms related to a bad water pump?

Can I drive with a water pump problem?

How often do water pumps need to be replaced?

This depends on the model of car and its driving conditions. The water pump does not wear like a tire or a ball joint, but eventually the bearing or impeller can fail inside the pump.

How are water pump issues diagnosed?

The technician will check for leaks around the water pump area. While the engine runs, a stethoscope may also be used to check for noise from the water pump bearing. If it's not buried away, the belt driving the pump, as well as its pulley, will be visually inspected. For electric water pumps on some newer cars, the engine's computer will be checked for codes, and tests will be performed to determine the proper repair.

How is a water pump replaced?

To replace the water pump, the cooling system is drained and the fan belt or timing belt and pulleys are removed. Depending on which belt drives the pump, that belt and other related components will be removed, followed by the pump itself. Engine surfaces are cleaned, a new water pump and gasket are installed, and the cooling system is refilled.

RepairPal recommendations for water pump issues

The entire cooling system, including coolant hoses and fittings, the radiator, the coolant fan and the fan clutch, should be inspected when replacing the water pump. To help prevent future issues, we recommend replacing the thermostat at this time, as well. If the water pump is driven by the timing belt, it's customary to replace the pump any time the belt is replaced.

Can I replace the water pump myself?

The vast majority of water pumps only require simple tools to replace. But the procedures vary wildly from car to car. Prior to ordering parts or attempting this repair yourself, look online for guides on how to replace the part in your vehicle. Some will require significant disassembly of the front end of the motor — in these cases, you may be better off letting a repair shop handle the job.