N20 judder in hot weather caused by the wastegate pressure converter

Engine / equipment

N20 2.0 turbo petrol in the X1 (E84), Z4 (E89), 5 Series (F10), X3 (F25) and 3 Series (F30)

Period mentioned

Approx. 2012–2015

Symptoms

Repeated judder or surging when accelerating between 3,000 and 5,000 rpm in hot weather, with no engine light and no stored fault codes.

Possible cause described

The electropneumatic pressure converter (EPDW) that moves the turbo's wastegate valve binds internally. BMW describes it in its technical bulletin SI B11 10 12 of January 2013.

Check for the garage

Tell the garage it only happens in hot weather and between 3,000 and 5,000 rpm even with no codes; ask them to check the wastegate pressure converter (next to the oil filler cap) before replacing coils, injectors or the turbo.

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