B58 Electric Water Pump Replacement

Fits US B58 cars

G20 M340i (B58TU) first, then Gen 1 F30 340i, F22/F23 M240i, F32/F33/F36 440i, G30 540i, G01/G02 X3/X4 M40i, and G05 X5 40i. Pump mount and part numbers split between Gen 1, early G30/G01, and TU / B58C / B58D cars: use the rows below, not guesswork.

Gen 1 F-chassis carrier pump: 10 Nm
G30 540i / G05 X5 40i pump: 19 Nm

Before you start

The electric coolant pump sits on the component carrier (G20 M340i and Gen 1 F-chassis) or on a support at the crankcase (G30 540i / G05 X5 40i). BMW has no G20 M340i B58 pump replacement procedure in the F30-family repair doc set; for the G20 M340i, belt, drain, and carrier pump torque steps follow the F30 340i B58 doc unless your VIN says otherwise. When it leaks or fails, drain and refill the HT circuit with fresh coolant and work cooled only.

What you replace

Coolant pump, TU / B58C / B58D (G20 M340i and related TU cars)

11 51 8 482 251

Renew pump seal and connecting branch seal on install (TU catalog row). G20 M340i line torques: send us your VIN and we'll send yours.

Profile gaskets at TU pump (qty 2)

11 51 8 482 263

11 51 8 482 264

Connecting branch coolant line, TU

11 51 8 482 258

Renew when replacing the TU pump on G20 M340i. Send us your VIN and we'll send yours if your car differs.

O-ring at heat management module, TU

11 51 8 482 260

Coolant pump with support (G30 540i / G05 X5 40i)

11 51 8 650 986

Renew pump seal and HMM O-ring on install.

Main coolant pump, early G30 / G32 B58 (electric)

11 51 8 482 744

Main coolant pump, Gen 1 F-chassis (F30/F2x/F3x/F36)

Send us your VIN and we'll send yours.

Main coolant pump, G01/G02 X3/X4 M40i before B58D (to 07/2019)

Send us your VIN and we'll send yours.

Pump with flow switch before 11/2015 (Gen 1 F-chassis and G30 540i / G05)

Send us your VIN and we'll send yours.

Pump without switch from 11/2015 (Gen 1 F-chassis and G30 540i / G05)

Pump exchanges separately on later cars. Send us your VIN and we'll send yours.

Loctite 5970 sealing bead, Gen 1 F-chassis bead-style pump

83 19 0 404 517

Apply within 10 minutes at room temp; wait 25 minutes before startup after install.

Fresh HT coolant after pump work

HT fill volume: send us your VIN and we'll send yours.

Out in this order

Acoustic coverabove 20 degrees C only
Intake silencer and clean airGen 1 F-chassis; G20 M340i: send VIN
Struts and fan cowlGen 1 F-chassis path
A/C and alternatorG30 540i / G05: refrigerant first
Drain HT coolantcatch and dispose
Alternator beltrelieve tensioner
Electric coolant pumpGen 1 F-chassis and G20: up out of carrier; G30 / G05: with support
Vacuum fill and bleedvacuum filler kit
Reinstall intake, belt, cowl, A/Creverse the map

Steps, torque values and part rules come from BMW's repair instructions for electric coolant pump replacement. Part numbers come from BMW's parts catalog up to 2020. Check yours by VIN.

Drawing of the TU coolant pump with renewed seals before install with numbered dots: 1 Pump perimeter seal; 2 Electric coolant pump; 3 Pump wiring connector; 4 Branch hose port — Pump perimeter seal

Electric coolant pump

Pump wiring connector

Branch hose port

Generic layout: yours may differ.

Tools

Serpentine belt tool

Belt tensioner tool or a long breaker bar on the poly-V tensioner.

Vacuum filler kit

Coolant vacuum filler with a B48/B58 expansion-tank adapter and an inline strainer on the fill line.

Loctite gun, Gen 1 F-chassis bead path

Standard caulking gun for the Loctite 5970 cartridge.

Drain pans, torque wrench, refrigerant recovery (G30 540i / G05 path)

Replace a belt if coolant or oil contaminated it.

Steps

Remove acoustic cover

Unclip the acoustic cover at the marked mounts and lift it off only when ambient temperature is above 20 degrees C.
Open the intake path
1. Intake silencer plug
2. Intake silencer housing
3. Housing fasteners
Generic layout: yours may differ.
Remove the intake silencer or filter housing after unlocking plugs and opening clamps. G20 M340i: send us your VIN and we'll send the top-end teardown for your car.
Remove clean air pipe
1. Crankcase vent line
2. Clean air pipe opening
3. Pipe clamp area
Generic layout: yours may differ.
F30 340i, F22/F23 M240i, F32/F33/F36 440i: release the crankcase vent line, open clamps, and feed out the clean air pipe.
G20 M340i access before belt

G20 M340i: send us your VIN and we'll send access steps before the belt comes off.
Gen 1 F-chassis struts and cowl
1. Fan cowl edge
2. Strut brace mounts
3. Cowl lift direction
Generic layout: yours may differ.
F30 340i, F22/F23 M240i, F32/F33/F36 440i: remove front strut braces and cross connections, then lift the fan cowl off the radiator (7 Nm with fan / 6 Nm on reinstall). Optional underbody access needs the front stiffening plate back on before you drive.

Caution: Renew front strut tower screws at the cross connection on reinstall. Do not drive without the stiffening plate fitted.
G30 540i / G05 alternator path

G30 540i and G05 X5 40i (pump with support): recover refrigerant, disconnect the negative battery, remove the throttle body and charge air, then take off the alternator belt, alternator (38 Nm), and A/C compressor (38 Nm; refrigerant line 19 Nm).

Caution: no charger on the jump-start point while the battery is disconnected.
Drain HT coolant
1. Upper HT coolant hose
2. Auxiliary coolant line
3. Drain catch area
Generic layout: yours may differ.
Open HT coolant lines at the pump, catch fluid, and dispose of it. Do not reuse drained coolant when the pump is renewed.

Caution: hot coolant and hot surfaces burn. Wear PPE and work cooled.
Relieve the poly-V belt
1. Poly-V belt tensioner
2. Alternator drive belt
3. Tensioner mounting bolts
Generic layout: yours may differ.
Relieve the poly-V belt tensioner and remove the alternator drive belt before pump bolts come out.

Caution: the tensioner snaps back when preload is released; keep fingers clear.
Remove the coolant pump

Disconnect pump wiring and hoses, then remove the pump: G20 M340i and Gen 1 F-chassis pull the pump up out of the component carrier; G30 540i / G05 remove the pump with support.
Inspect seals and sleeve
1. Pump perimeter seal
2. Electric coolant pump
3. Pump wiring connector
4. Branch hose port
Generic layout: yours may differ.
Check sealing surfaces, the F30 fitting sleeve, and the sealing bead. Renew the complete pump if the sleeve or bead is damaged.
Gen 1 F-chassis Loctite bead

Gen 1 F-chassis bead-style pump: apply Loctite 5970 from the parts row within 10 minutes at room temp; wait 25 minutes before startup after install.
Install and torque pump

Fit the new pump and torque mounting bolts to 10 Nm on the Gen 1 F-chassis carrier path or 19 Nm on the G30 540i / G05 pump-with-support path. G20 M340i: torque carrier pump bolts per the F30 340i B58 repair doc (10 Nm) unless your VIN says otherwise.

Caution: G20 M340i TU pump: renew seals per the parts row; send us your VIN for line torques.
Connect coolant lines

Gen 1 F-chassis: reconnect HT lines at the pump per the F30 doc. G20 M340i: send us your VIN and we'll send line torques and seal steps for your TU pump.
Vacuum fill HT circuit

Refill the HT circuit with a vacuum filler and expansion-tank adapter using 7 bar shop air, pull vacuum to -0.8 to -0.95 bar, hold for 2 minutes, and keep 1 l to 2 l extra premixed coolant in the tank.

Caution: watering-can fill is not released. HT fill volume: send us your VIN and we'll send yours.
Run bleed routine

Fill both HT and LT circuits, keep terminal 15 on with low beam and hazards, and run the bleed routine.
- Idle at 1200 rpm during the routine.
- Rev to 3500 rpm for 10 seconds, then idle 30 seconds; repeat through about 11 minutes total after start.
- Do not bleed with an empty LT or HT circuit: the electric pump can dry-run.
Pressure test and level

Pressure-test the HT circuit at 1.5 bar for 2 minutes. After a cooled engine, set level 200 ml above the maximum mark. Open the expansion tank bleeder screw about 10 seconds if air remains.
Reinstall and torque

Reinstall intake, charge air, belt, fan cowl, struts, A/C, and battery in reverse of the teardown map, using the path torques already called out on the access steps.