Coolant leaks in extreme cold from the quick-connector O-rings

Engine / equipment

X3 (G01), X4 (G02), X5 (G05) and X7 (G07) built up to 31/3/2019

Period mentioned

2017–2019

Symptoms

Only in severe cold (−15 °C or below): a "top up coolant" warning and some fluid under the car. At normal temperatures it does not leak and the engine temperature is fine.

Possible cause described

The O-rings that seal the coolant pipes' quick connectors stop sealing at −15 °C or below. BMW describes it in bulletin SIB 17 03 20 (May 2020) and has the affected pipes replaced when a leak is confirmed. Codes from the charge-air cooling circuit may be stored (20A201, 20A209).

Check for the garage

Note the outside temperature when the warning appears and only check the level with the engine cold. At the garage, have them look for the leak at the coolant pipes' quick connectors, including the low-temperature circuit.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database