Overview
The story
The N55 replaced the N54's two turbos with one twin-scroll turbo and added Valvetronic. A published reference lists it in the E90 335i from 2010 and the F30 335i from 2011, and says the B58 began replacing it in 2015. A published reference
Specs
Versions
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Single twin-scroll turbo N55 A published reference
302 hp and 295 lb-ft
In E90 BMW 3 Series, 2011–2013; F30 BMW 3 Series, 2012–2015; F32 BMW 4 Series, 2014–2016; F10 BMW 5 Series, 2011–2016; F25 BMW X3, 2011–2017; E70 BMW X5, 2011–2013; F15 BMW X5, 2014–2018
Figures
- Displacement: 3.0L (2,979 cc) A published reference
- Bore × stroke: 84 × 89.6 mm A published reference
- Block: Aluminum A published reference
Watch out
Faults owners and the press report, and how to spot each one.
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Electric water pump failure Every version
One source so far
Check: Watch the temperature and listen for the fan running flat out.
BMW Tuning says failures are cited as early as 30,000 to 40,000 miles, while others pass 120,000. A seller's guide (unofficial)
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Leaking oil filter housing gasket Every version
One source so far
Check: Look for oil on the belt tensioner and drive belt.
BMW Tuning says the oil commonly reaches the belt, which can slip or snap, and recommends replacing the housing on engines past 100,000 miles. A seller's guide (unofficial)
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Leaking valve cover and PCV valve Every version
One source so far
Check: Look for oil on the plug threads and smell for burning oil.
BMW Tuning says the valve cover typically lasts about 100,000 miles, and that its built-in PCV valve eventually fails. A seller's guide (unofficial)
Owning
Maintenance
No service schedule is added yet.
What owners and buyers say
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Sought after
A fairly reliable turbo six Every version
One source so far
BMW Tuning says the N55 is a fairly reliable engine, that none of its common problems is necessarily major, and that most of its problem parts are not expensive. A seller's guide (unofficial)