BMW N54

Design

The N54 was produced alongside the naturally aspirated BMW N53 engine; both engines have direct injection, double-VANOS (variable valve timing), an open-deck engine block and an electric water pump. The n54 has an aluminium engine block (instead of the magnesium alloy used by the N53), a displacement of 2979 cc and does not have valvetronic (variable valve lift).

Turbocharging is a key difference between the N54 and BMW's previous straight-six engines. The N54 has two small low-pressure turbochargers to minimise turbo lag. BMW marketed the twin-turbo as "TwinPower Turbo", although the term has since been used for engines which have a single twin-scroll turbocharger. The boost pressure is 8 psi and an air-to-air intercooler is used. Compared with the naturally aspirated BMW N52 that it replaced as BMW's highest performance six-cylinder engine, the N54 produces an additional 45 bhp and 80 lbft.

The N54's direct injection system (called "High Precision Injection" by BMW) uses piezo injectors. Its N55 successor uses solenoid-type injectors, because the piezo injectors are more expensive and not reaching their full potential to obtain the "lean burn" benefit.

Versions

All versions have a bore of 84.0 mm, a stroke of 89.6 mm, a compression ratio of 10.2:1 and the redline is 7000 rpm.

225 kW version

The initial version of the N54 is officially rated at 225 kW and 400 N·m. However, these figures are considered to be under-rated, and independent testing has resulted in estimates of 311 bhp and 422 Nm.

Applications:

• 2006–2010 E90/E91/E92/E93 335i
• 2007–2010 E60/E61 535i
• 2007–2010 E82/E88 135i
• 2008–2010 E71 X6 xDrive35i
• 2009–2016 E89 Z4 sDrive35i

240 kW version

A variant of the N54B30 with higher peak power and torque is used in the 2008-2012 740i and E92 335is.

Applications:

• 2008–2012 F01 740i
• 2011–2013 E92/E93 335is

250 kW version

The most powerful version of the N54 is found in the E82 1 Series M Coupe and the E89 Z4 sDrive 35is.

Applications:

• 2011 E82 1 Series M Coupe
• 2011–2016 E89 Z4 sDrive35is

Alpina

Biturbo engine by Alpina based on the N54B30, with upgrades including the engine control unit, oil cooler and pistons.

265 kW version

This is Alpina's initial version of the N54, producing 265 kW.

Applications:

• 2007–2010 Alpina B3 (E90)

294 kW version

Applications:

• 2010–2013 Alpina B3 S

300 kW version

Applications:

• 2012–2013 Alpina B3 GT3

Critical reception

Car & Driver noted the N54 had minimal turbo lag and "in feel and sound the twin-turbo could pass for naturally aspirated". The N54-engined F01 740i was also praised for its linear power delivery.

Comparing the N54-engined E60 535i with the 550i (using a 4.8–litre naturally aspirated V8), one reviewer noted that the V8 model had more torque but was "only marginally quicker than the 535i" and that the additional weight of the V8 engine was noticeable on twisty mountain roads.

High-Pressure Fuel Pump failures

In the United States, some N54 engines experienced failures of the High Pressure Fuel Pump (HPFP), resulting a class action lawsuit, a voluntary recall and an extended warranty for the HPFP.

Failure of the HPFP can cause the engine to suddenly stop functioning, which has caused several near-misses on highways. BMW was aware of HPFP problems, describing them in internal Technical Service Bulletins as "driveability problems".

In April 2009, a class action suit was filed against BMW in connection with HPFP failures. BMW settled the suit in June 2010. On 26 October 2010, following an ABC News story about HPFP failures, BMW announced a recall of vehicles with the pump in question from manufacturing years 2007–2010. The recall was applied to 130,000 cars, resulting in the replacement of the HPFP in approximately 40,000 of these cars.

In the United States, the warranty period for the HPFP was increased to 10 years and 120000 mi.

On some cars, the HPFP was replaced multiple times without resolving the issue, potentially leading to the car being refunded under the Lemon Laws in some states.

Extended warranty in the United States

The High Pressure Fuel Pump issue caused BMW North America to extend the warranty for this pump to 10 years or 120000 mi.

The warranty period for the fuel injectors was also increased, to 10 years or 120000 mi. An updated design for the fuel injectors was also introduced.

Due to problems with rattling wastegates caused by premature bushing wear, BMW extended the warranty period for wastegate-related issues to 8 years or 82000 mi.

These warranty extensions only apply to the United States.

References

References

1. "Direct Injection, Turbo Pay Off For BMW".
2. "BMW takes home 4 awards from International Engine of the Year competition - N54 and S65 continue dominance".
3. "BMW's Newest I-6 Better, Not Bigger".
4. "Part cross-reference - 13537537319 Sensor, high-pressure".
5. "BMW N54 engine".
6. "Motor Engine: BMW N54 inline 6 twin turbo".
7. (4 May 2015). "Engine Guide BMW N54/N55".
8. "5' F10 530i Waterpump - Thermostat".
9. "BMW N54 and N55 Six Cylinder Turbocharged Engines".
10. "BMW EfficientDynamics: Petrol engines with BMW TwinPower Turbo Technology".
11. (16 November 2016). "2017 BMW X4 M40i Instrumented Test".
12. "2011 BMW 335i Sedan".
13. (May 2007). "2008 BMW 5-series - First Drive Review". Car and Driver.
14. "BMW Technology Guide: High Precision Injection".
15. "BMW's Newest I-6 Better, Not Bigger".
16. (26 May 2009). "The latest BMW engine: N55 - found in the BMW 5 Series GT".
17. (14 May 2010). "First Drive Review - 2011 BMW 335i Sedan".
18. "Press release- Performance Engine Software for BMW 335 Models".
19. "BMW 335i Coupe (2006) review".
20. (July 2025). "2009 BMW 5-series E61 phase-II (Touring) Wagon X (4WD) full range specs".
21. (14 May 2010). "2011 BMW 740i / 740Li - First Drive Review".
22. "2011 BMW 335is First Drive". Insideline.com.
23. "2010 BMW 335is Coupé".
24. "New BMW 7-Series F01 Specifications and Photos".
25. "BMW 1-Series M Coupe Review".
26. "Dyno-Tested: 2011 BMW 1 Series M Coupe".
27. "BMW 3 Series E90/91/92/93: ALPINA Automobiles".
28. "2007 BMW 335i Coupe - Road Test".
29. "2012 BMW 740i Sedan - Editors' Notebook".
30. "V-8 with Extra Weight- 2008 BMW 5-series".
31. Cohan, Peter. (15 July 2016). "BMW's Engine Problems: A Safety Risk to Drivers – and the Company?".
32. "Kershaw, Cutter & Ratinoff takes on BMW in class action suit regarding defective HPFP".
33. "Jay Alan Morane vs BMW North America- April 10 2009".
34. (26 October 2010). "ABC News airs big expose on BMW N54 engine problems, lawsuits".
35. Morran, Chris. (2010-10-26). "BMW Recalls 150,000 Cars Over Fuel Pump Failures". Consumerist.
36. (26 October 2010). "Consumerist: BMW Recalls 150,000 Cars Over Fuel Pump Failures". Consumerist.
37. "BMW Recalls Some Turbo-Charged Cars Following ABC News Investigation".
38. "High Pressure Fuel Pump for Turbo vehicles - BMW 335i, 335xi".
39. "What's the deal with all these Lemon/Buyback 335i's?".
40. (27 December 2016). "N54: The best Plugs, Injectors and Coils Thread".
41. (3 January 2017). "BMW Fuel Injector – Ext'd Warranty, Reimbursement".
42. (16 August 2013). "N63, N74, N54 Injector Update".
43. "N53 330i Powweerrr loss".
44. (24 November 2017). "BMW Turbo Upgrades For The Infamous N54".
45. (August 2016). "BMW 135i 335i 535i N54 Wastegate Rattle Fix".
46. (2012-08-16). "N54 Engine warranty extended to 8 Years/82,000 Miles (Wastegates Only)".