BMW i4, i5, i7 or iX Coolant Under the Car? Check Every Changeover Valve

Check Every Coolant Valve

Coolant under a BMW i4, i5, i7, or iX is not an invitation to open the reservoir and hunt around orange cables. BMW SIB 17 01 24 Revision 3 directs trained personnel to inspect every changeover valve fitted to the vehicle for active leakage or dried residue. Finding one wet valve does not excuse the others; finding none sends the case to ISTA and approved cooling-system test equipment.

Once the vehicle is cool, de-energized as required, and in qualified hands, a pressure-hold and vacuum-fill machine can support the controlled cooling-system work. The AUTOOL SC301 cooling system tester and filler is one compatible route. It cannot make high-voltage work safe, identify which valve leaked, replace ISTA bleeding or function tests, or justify a generic pressure setting on this BMW.

The reader’s job is to recognize the pattern and preserve evidence. The HV-qualified technician’s job is to turn that evidence into a complete valve census.

Stop before the coolant circuit becomes an HV shortcut

If the car reports a serious drive warning, cabin heat disappears in freezing weather, coolant is pouring out, vapor is present, or temperature behavior is abnormal, park safely and arrange recovery. Never open a hot cap. Do not reach beneath an energized BEV or probe orange wiring.

BMW states that work requiring disconnection or removal of high-voltage battery components must be performed by personnel with applicable HV training. Even when a visible coolant part is low voltage, access and isolation may place the technician near high-voltage equipment.

Photograph the cold level, puddle position, undertray edge, dried residue, and exact Check Control message. Record whether the leak appeared after charging, cabin preconditioning, driving, or parking, and whether heater output changed.

Count the valves fitted to this model

The bulletin identifies four BEV families and a possible valve count:

BMW platform	Vehicle	Possible changeover valves
G26	i4 Gran Coupe	1
G60	i5 Sedan	3
G70	i7 Sedan	1
i20	iX SAV	2

These counts explain why “we replaced the leaking valve” may be incomplete on an i5 or iX. Confirm exact VIN and equipment in current BMW information; the table is not a map for untrained access.

Separate active wetness from dried evidence

An active leak may form a bead, wet a seam, or create a fresh track. A previous leak can leave dried coolant around the valve even when the bay is dry today. Photograph both. Clean only after the original state is recorded, then reproduce under the approved test or thermal condition.

Coolant can travel along hoses, brackets, shields, and undertrays. Start at the highest fresh point. A puddle under the rear of a shield does not prove that the part directly above the puddle is the source.

Check every valve, not only the first one

BMW’s correction explicitly says to check all changeover valves, including two or more where fitted. Give each valve the same record: location, part number where accessible, production date, active wetness, dried residue, surrounding hose condition, and result after cleaning/retest.

Do not let the first obvious leak end the inspection. A second valve with old residue can become the next customer comeback after the system is refilled and returned to service.

Use production dates only inside the bulletin

The bulletin discusses improved valve production and gives date-based replacement direction for the relevant part number. A production date is supporting evidence only after the correct valve and vehicle have been identified. It is not a universal expiration date for every BMW coolant valve.

Have the technician use current AIR/ISTA and parts data because revisions, fitted quantities, part numbers, and procedure details can change. A TSB also does not by itself establish recall or warranty status.

Pressure-test only after HV isolation is valid

If testing is needed, the vehicle must be cool and the correct circuit, adapter, cap rating, maximum pressure, isolation state, and hold period must come from BMW information. Inspect the test equipment and verify its own connection does not leak. Never use unregulated shop air.

A falling pressure reading says the sealed test boundary did not hold. It does not name a valve. Correlate the pressure record with the first returning wet point and the vehicle’s circuit state.

Move to ISTA when the valve census is clean

BMW says that if no changeover valves are leaking, further diagnosis should proceed with ISTA and cooling-system test equipment. That branch matters. It prevents a dry valve from being replaced solely because the symptom resembles the bulletin.

Other causes can include a hose or connection, reservoir/cap, heat exchanger, pump, heater circuit, service spill, damaged underbody component, or a leak that appears only when a particular valve is commanded. Guided activation and correct circuit bleeding may be needed to expose it.

Verify level, heat, faults, and bleed together

BMW warns not to reuse drained coolant in this repair. After the confirmed work, use the specified fluid and approved filling/bleeding procedure, restore all shields and connectors, and run the required valve/heater function checks. Let the car cool completely on level ground before comparing the cold level.

Verification is a stable cold level, dry valve record across every fitted position, normal cabin heat, no relevant Check Control message or returning faults, and successful ISTA bleed/function completion. A clean floor immediately after refilling is only the beginning.

Official references

• BMW SIB 17 01 24 Revision 3: coolant leak at changeover valve
• BMW safety and emission recall lookup