Important Engine Restriction
This pump primarily serves BMW vehicles using:
- N54 3.0L twin-turbo inline-six
- N55 3.0L single-turbo inline-six
Do not order solely because the vehicle has a 3.0L BMW engine. Naturally aspirated N51 and N52 engines can use different electric pumps and related hardware. BMW built several 3.0L engines because one version apparently would have made cataloging too easy.
Replacement Part Numbers
Primary BMW references include:
- 11517632426
- 11-51-7-632-426
- 11517563659
- 11517588885
- 11517602123
- 7632426
- A2C53326031
- A2C59514607
- 41504E
- 941504E
BMW lists 11515A05704 as the newer replacement for 11517632426.
Part number 11206043003 is commonly associated with installation hardware or aftermarket cross-reference data and should not be treated as the primary water-pump OE number.
Numbers 11517586928 and 11517586929 appear in some broad aftermarket listings but may apply to different BMW cooling-system configurations. Match the original number rather than treating every number in an online title as sacred scripture.
Package Contents Require Verification
The supplied description conflicts about what is included. It calls the product both a water pump and a “water pump with thermostat” kit.
Before ordering, confirm whether the package contains:
- Electric coolant pump
- Thermostat
- Pump mounting bolts
- Gasket or sealing components
- Electrical connector or harness
- Installation instructions
The pump may fit both N54 and N55 applications while the required thermostat varies by chassis and production date. A bundled thermostat should therefore be verified separately by VIN.
How the BMW Electric Water Pump Works
Unlike a mechanical pump driven by the accessory belt, this electric pump receives commands from the engine-control module. Pump speed can change based on:
- Engine coolant temperature
- Engine load
- Turbocharger heat
- Requested cabin heat
- Driving mode
- Post-shutdown cooling requirements
This arrangement improves thermal control and reduces unnecessary mechanical drag. Unfortunately, an electric pump can also stop abruptly when its internal electronics fail, because BMW ownership occasionally includes surprise engineering seminars.
Symptoms of a Failing BMW Electric Water Pump
Common symptoms include:
- Engine-temperature warning
- Reduced-power or limp mode
- Radiator fan running at very high speed
- Cooling fan running shortly after a cold start
- Rapid overheating
- Weak or inconsistent cabin heat
- Coolant circulation faults
- Pump communication or speed-deviation codes
- Coolant leakage near the pump
- Pump failing to activate during a diagnostic test
An overheating warning should be taken seriously. Stop driving if the temperature warning turns red, coolant is leaking or steam appears. Continuing to drive can damage the cylinder head, head gasket, turbocharger or catalytic converters.
Our guide on why a car overheats while driving explains how coolant loss, restricted flow and fan problems create different overheating patterns.
Diagnose Before Replacing the Pump
The electric water pump is a common failure point, but it is not the only possible cause of overheating.
Check:
- Coolant level with the engine completely cold.
- Stored BMW-specific diagnostic codes.
- Pump activation using a compatible scan tool.
- Actual versus commanded pump speed.
- Pump power supply and ground.
- Electrical connector condition.
- Cooling-fan operation.
- Thermostat operation.
- Evidence of external coolant leakage.
- Whether the cooling system was correctly bled after previous repairs.
If coolant loss is present, follow our coolant-leak diagnostic guide before condemning the pump.
Why Replace the Thermostat at the Same Time?
The thermostat is mounted near the pump and shares much of the same labor. Replacing both components together is common when mileage and service history justify it.
A complete repair may require:
- Electric water pump
- Correct application-specific thermostat
- New aluminum mounting bolts
- Approved BMW coolant
- Distilled water when using concentrate
- Hose seals or O-rings
- Correct bleeding procedure
Do not reuse single-use aluminum bolts when BMW service information specifies replacement. The bolts are intentionally lightweight and torque-sensitive; tightening them by feel is an excellent method for converting a repair into an extraction project.
Installation Notes
This repair requires access from underneath the vehicle and can be difficult because of limited space around the pump, thermostat and hoses.
Basic installation includes:
- Letting the engine cool completely.
- Disconnecting the battery as directed by service information.
- Raising and supporting the vehicle safely.
- Removing the necessary underbody panels and intake components.
- Draining the coolant.
- Disconnecting the pump electrical connector.
- Removing the thermostat and coolant hoses as required.
- Installing the correct pump, thermostat and new bolts.
- Refilling with BMW-approved coolant.
- Running the electric bleeding procedure.
- Pressure-testing the cooling system.
- Clearing faults and verifying commanded pump operation.
Never open a hot cooling system. Pressurized coolant can cause severe burns.
For coolant-service guidance, see our article on how to flush and refill a cooling system.
BMW Electric Cooling-System Bleeding
Many compatible BMW models use an automated bleeding procedure that operates the electric pump with the engine off. The exact process varies, but commonly involves:
- Connecting a battery charger
- Switching the ignition on without starting the engine
- Setting the heater to its highest temperature
- Setting the blower to a low speed
- Holding the accelerator pedal down for approximately ten seconds
- Allowing the pump cycle to complete
Use the procedure specified for the exact chassis. Do not start the engine during the automated cycle unless instructed.
Maintaining battery voltage is important because the pump and blower consume considerable power during bleeding. A weak battery can interrupt the process and leave air trapped in the system.
Frequently Asked Questions
What vehicles use BMW water pump 11517632426?
It is commonly used on BMW N54- and N55-powered models including the 135i, 335i, 535i, 535i GT, 640i, 740i, X1, X3, X4, X5, X6 and turbocharged E89 Z4.
Does it fit every BMW 3.0L engine?
No. The engine family, chassis and production date matter. Naturally aspirated N51 and N52 applications may require a different pump.
Does it fit a BMW Z4?
It fits applicable E89 Z4 sDrive35i and sDrive35is models. It should not be advertised as fitting every 2009–2012 Z4.
Is the thermostat included?
The description is inconsistent. Confirm the package contents before purchase. If included, verify the thermostat number separately for the vehicle.
Is this water pump belt-driven?
No. It is an electric pump controlled by the engine-management system.
Should the mounting bolts be replaced?
Yes, when the application uses single-use aluminum bolts. Verify whether new bolts are included.
Can a failed pump make the cooling fan run at full speed?
Yes. The engine computer may command maximum fan speed when pump operation or coolant circulation becomes unreliable.
Will this pump fix every BMW overheating problem?
No. Low coolant, trapped air, thermostat failure, radiator blockage, fan problems, wiring faults and combustion leakage can produce similar symptoms.
What supersedes BMW 11517632426?
Current BMW catalog information lists 11515A05704 as its replacement.
BMW catalog confirmation is available through the 11517632426 OE parts listing. Installation and kit information can also be reviewed through FCP Euro’s BMW water-pump replacement kit and BimmerWorld’s N54/N55 electric water-pump reference.
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