Mercedes-Benz R320 BLUETEC Water Pump Replacement Cost
How Much Does a Water Pump Replacement Cost?
Water Pump Replacement Service and Cost
The water pump, also known as the coolant pump, circulates coolant through the engine's cooling system.
The water pump pushes coolant through a vehicle's cooling system. The water pump is driven by an accessory belt at the front of the engine or by the timing belt, or by the timing chain.
A worn water pump has far reaching effects. If the water pump is not maintaining proper coolant circulation the engine will overheat, causing leaks, possible head gasket damage, and ultimately a failed motor. Failure to shut down an engine while overheating will eventually cause stalling, necessitating a tow.
Repair intervals vary greatly by vehicle and driving conditions. The water pump does not wear like a tire or a ball joint, but eventually the bearing or impeller can fail in the pump. When noisy, leaking, or unable to properly circulate coolant, the water pump needs to be replaced.
Water Pump Replacement Repair Information
The technician will check for leaks and wetness around the water pump area. With the engine running, they may also use a stethoscope to check for noise indicating wear of the water pump bearing. If visible, the belt driving the pump will be inspected, along with the water pump pulley to be sure the pump is being driven properly. In the case of electric water pumps on some newer cars, the engine's computer will be checked for codes, and the relevant tests will be performed to determine the proper repair.
To replace the water pump, the cooling system is drained and the fan belt or timing belt and pulleys are removed. If the water pump is operated by a fan belt, the hose going from the water pump to the radiator is removed, as are the bolts securing the water pump to the engine. The water pump is removed from the engine, and the engine surfaces are cleaned. A new water pump and gasket are installed, and the cooling system is refilled with fresh coolant. If the water pump is operated by the timing belt, the timing belt covers, timing belt, and all related components are disassembled. The hardware securing the water pump to the engine is removed, and the water pump is removed from the engine. The surfaces are cleaned and a new water pump and gasket are installed. All timing belt–related components, fan belts, and pulleys are installed, and the cooling system is refilled with fresh coolant.
Be sure to follow the specific procedures for your vehicle. Proper gasket handling, torque specs, and sealant usage are necessary for an effective repair. When refilling the cooling system, the manufacturer recommended coolant should be used. There are many bearing noises that could come from an engine bay. Proper care should be taken to diagnose them. The entire cooling system—including all of the coolant hoses and fittings, radiator, coolant fan(s), and fan clutch (if equipped)—should be inspected when replacing the water pump. To help prevent future issues, we recommend replacing the thermostat when the cooling system has been opened for repairs (e.g. water pump or radiator replacement) or during a system flush. The fan clutch may also be removed to access the water pump, and should be replaced if worn or leaking. When replacing the water pump, the drive belts may need to be removed, they should be replaced if worn.The water pump may be driven by the timing belt. It this case, it is common to replace the water pump when the belt is replaced.
Due to the overheating risk, a car with a leaking water pump should not be driven. Coolant leaks allow air into the cooling system, creating air pockets where hot spots can occur, damaging other components and increasing the risk of head gasket failure. If the water pump is leaking, consider getting the vehicle towed.
Repairing your own car is an extremely rewarding process that can also save you money. But before you dive in, it’s important to be sure the issue has been properly diagnosed. Seemingly obvious symptoms can lead the inexperienced down a rabbit hole of replacing parts that don’t fix the problem. Proper diagnosis can save more money than guessing at what’s broken! If you're unsure you have the right tools or experience to diagnose a problem, consider reaching out to a RepairPal Certified Shop. The vast majority of Water Pumps only require simple tools to replace. However, 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 specific vehicle. Some will require significant disassembly of the front end of the motor in order to extract the Water Pump. Special procedures may also be required to fill or bleed the cooling system after completion.