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Estimates last updated January 28, 2026

2003 Lexus IS300 Water Pump Replacement Cost

The average cost for a 2003 Lexus IS300 Water Pump Replacement is between $865 and $1,137.

Labor costs are estimated between $415 and $609 while parts are priced between $451 and $528.
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.

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.

Water pumps require replacement if they begin to leak coolant or become noisy. Leaking water pumps can result in damage to the drive and timing belts.

A failed water pump can be caused by problems in the cooling system, such as a failing thermostat, radiator, or head gasket.

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.

Lexus Water Pump Replacement Cost Estimates

The average cost for a Water Pump Replacement is between $865 and $1,137 but can vary from car to car.

Lexus IS300 Water Pump Replacement Cost by Year

The average cost for a Lexus IS300 Water Pump Replacement is between $865 and $1,137 but can vary from car to car.

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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.

Water pumps require replacement if they begin to leak coolant or become noisy. Leaking water pumps can result in damage to the drive and timing belts.

A failed water pump can be caused by problems in the cooling system, such as a failing thermostat, radiator, or head gasket.

What are the symptoms related to a bad water pump?

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?

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.

When replacing the water pump, the drive belts and/or timing belt may need to be removed. The belts should be replaced if they show signs of wear or coolant damage.