Bulletin
Engine code

IA Technical Bulletin

BMW N52 Engine Guide

Engine: N52

Bulletin text

N52 · 2,996 cc (N52B30) and 2,497 cc (N52B25) · normally aspirated inline-6 with Valvetronic · built 3/2005-10/2013 in US-catalog cars · 3 Series, 5 Series, 1 Series, Z4, X3, X5

The N52 is a normally aspirated inline-6 with a composite magnesium-aluminum crankcase and Valvetronic variable valve lift. BMW's parts data lists it in US-catalog 3 Series, 5 Series, 1 Series, Z4, X3 and X5 models.

BMW's training material lists the M54 and M56 as the six-cylinder engines that came before it, and says it saves about 10 kg (22 lb) over the previous six-cylinder generation. It was first fitted to the E60, E61 and E90.

BMW's parts data lists N52 engines in US-catalog cars built from March 2005 to October 2013. It uses two N52 labels, N52 and N52N, and also lists a separate N51 label on US-catalog 128i and 328i types. BMW's recall bulletins add the labels N52K and N52T. This guide says which label each statement uses.

Quick read

Ownership position: Not established yet. We are still researching this engine.
Reliability: No verdict yet. BMW has run recall campaigns on the PCV valve heater (17V-683, 19V-273, 22V-119) and the VANOS housing bolts (14V-176, 23V-707). IAIK, from our own shop: the N52 has been unusually tolerant of neglect; see The Insider Read.
Cost to own: Not established yet. No BMW document gives a repair cost or interval.
Power potential: Not established yet. BMW's own US output figures run from 215 hp (325i at launch) up to 260 hp (X3 3.0si).
Main watch item: Open recalls. Check the VIN with BMW or NHTSA.

N52 At a Glance

Question	Practical answer
Sold in US-market BMWs?	Yes. BMW's parts data lists N52 and N52N engine types in its US catalog.
Displacement	2,996 cc (N52B30) and 2,497 cc (N52B25). The documents opened do not say whether any US-market car used the 2.5 liter.
Factory output (US cars)	About 215 hp to 260 hp depending on car and year. Each figure and its source is in Technical Specifications.
Engine oil	6.5 liters with the filter (about 6.9 US quarts). BMW's February 2017 oil chart lists 5W-30 LL-01 or 0W-30 LL-01FE for model year 2011 and older gasoline engines.
Reliability profile	No family-wide verdict. BMW's recalls name two systems: the crankcase ventilation (PCV) valve heater and the VANOS housing bolts.
Best ownership indicator	Not established yet.
Typical annual planning budget	Not established yet.
Possible first-year catch-up	Not established yet.
Common tuned street range	Not established yet.
Before buying	Ask a BMW dealer or NHTSA to check the VIN for open recalls on the PCV valve heater and the VANOS housing bolts.

Where you find it

The table follows BMW's parts data for its US catalog. The 323i appears in that catalog as well. The parts data ends in December 2019, so later changes are not covered.

Label in BMW parts data	Chassis and models	Built
N52	E60 sedan 525i and 530i; E60 525xi and 530xi; E61 wagon 530xi	525i and 530i 3/2005-2/2007; xi models 4/2005-2/2007
N52	E90 sedan 325i, 330i, 325xi, 330xi, 323i; E91 wagon 325xi	325i and 330i 3/2005-8/2006; other models 9/2005-8/2006
N52	Z4 roadster (E85) 3.0i and 3.0si; Z4 coupe (E86) 3.0si	roadster 1/2006-8/2008; coupe 4/2006-8/2008
N52N	E60 LCI sedan 528i and 528xi	3/2007-12/2009
N52N	F10 sedan 528i	6/2010-8/2011
N52N	E90 sedan 328i, 328xi and 323i; E91 wagon 328i and 328xi	E90 9/2006-12/2011; E91 9/2006-5/2012
N52N	E92 coupe 328i and 328xi; E93 convertible 328i	E92 6/2006-6/2013 (328xi from 9/2006); E93 12/2006-10/2013
N52N	E82 coupe and E88 convertible 128i	12/2007-10/2013
N52N	E83 X3 3.0i and 3.0si; F25 X3 xDrive28i	X3 3.0i 8/2006-7/2010, 3.0si 8/2006-8/2010; xDrive28i 12/2010-3/2012
N52N	E70 X5 3.0si	10/2006-3/2010
N52N	E89 Z4 sDrive30i	2/2009-8/2011

BMW's recall production windows start a little earlier than these build windows (the 3 Series sedan window in recall 22V-119 begins February 1, 2005).

Technical Specifications

Specification	Detail
Layout	Inline 6-cylinder, 4 valves per cylinder
Bore x stroke, N52B30	85 mm x 88 mm
Bore x stroke, N52B25	82 mm x 79 mm
Compression ratio	10.7:1 (N52B30) and 11.0:1 (N52B25)
Firing order	1-5-3-6-2-4
Valvetrain	Valvetronic II with intake valve lift from 0.18 mm to 9.9 mm, double VANOS on both camshafts (vane-type units that are not interchangeable between intake and exhaust).
Intake	3-stage DISA resonance intake manifold of thermoplastic
Engine management	Siemens MSV70 at launch; MSV80 with the slightly modified N52.
Variant codes in BMW tables	N52B25U1, N52B25O1, N52B30U0, N52B30M1, N52B30O1. In BMW's code, O means upper power stage, M medium and U lower.
Output, N52B30 launch engine (US 330i)	255 hp (190 kW) at 6,600 rpm, 300 Nm from 2,500 to 4,000 rpm
Output, 325i at launch	215 hp
Output, 328i coupe (N52N in BMW parts data)	230 hp and 200 lb-ft
Output, X3 3.0si (N52N)	260 hp at 6,600 rpm and 225 lb-ft at 2,500 rpm
Output, 2011 X3 xDrive28i (N52N)	240 hp at 6,600 rpm and 230 lb-ft from 2,600 to 3,000 rpm
US variants	BMW's launch training says the B25 and B30 were to be offered in the US only as the upper output stage
Engine speed limit	For the N52B30, BMW's training gives a 7,000 rpm governed cutoff, while BMW's technical data table lists 6,550 rpm (plus or minus 50) as the maximum permissible speed. The documents do not explain the difference.
Engine weight	161 kg (N52B30)
Engine oil	6.5 liters with filter. BMW's February 2017 oil chart lists 5W-30 LL-01 or 0W-30 LL-01FE for model year 2011 and older gasoline engines, and 0W-30 LL-01FE for N51, N52K and N52T in model years 2012 to 2015. BMW's launch training listed SAE 5W-30.
Fuel	91 octane listed (98 RON)
Emissions certification	ULEV 2 for the launch engine

The Insider Read

IAIK means IA-insiders knowledge. Our collected BMW technical and ownership notes.

IAIK calls the N52 the most surprising engine it sees in our shop for how much neglect it takes.

IAIK has seen N52 cars come in that had gone 20,000 miles without an oil change, with the engine still running.

In IAIK's experience these owners often arrive with a parts estimate as large as the car's original sticker price, decline it, have the oil changed and keep driving, and the engine keeps going.

IAIK gives that as shop experience with neglected cars, not as a reason to skip maintenance.

In our shop, IAIK has seen four N52 cars come in above 400,000 miles.

IAIK reports that two of them were still on their original 6HP automatic transmission, one had its transmission rebuilt at another shop and one had it replaced.

The one repair IAIK saw all four need was the transfer case, so all four were all-wheel-drive cars, and IAIK saw one of them also need a rear differential.

IAIK's pick for the best daily-driver reliability that still keeps BMW driving fun is a car with the N52, depending on the chassis.

IAIK also singles out the N52 F10 528i as a rare find with a more comfortable ride. BMW's parts data lists the F10 528i built 6/2010 to 8/2011 as the only US F10 with the N52; F10 528i cars built from 9/2011 carry the N20, and US N52 cars such as the E93 328i convertible were built until 10/2013, so the F10 was not the last N52 car.

Factory Deep Dive

Block and bottom end

BMW's training describes a two-material crankcase: magnesium alloy cast around an aluminum-silicon insert. The insert holds the coolant passages, which keeps coolant away from the magnesium. A separate magnesium bedplate closes the bottom, with sintered steel inlays at the main bearings. BMW's training names the magnesium alloy AJ62.

BMW's training lists a cast-iron crankshaft on 7 main journals and connecting rods with a tapered small end and a cracked big end. There are no iron cylinder liners; the bores run in Alusil.

To prevent contact corrosion on the magnesium, BMW's training specifies single-use aluminum bolts for parts mounted to the outside of the engine, and non-conductive oil pan and head gaskets between the magnesium crankcase and the aluminum parts. BMW's training says only genuine BMW spare parts are to be installed where parts meet the magnesium.

Cylinder head and valvetrain

The head is Alusil aluminum and the cylinder head cover is magnesium. Valvetronic varies the intake valve lift with a servomotor, eccentric shaft and intermediate levers, so load is controlled mostly by valve lift rather than the throttle. Both camshafts are phased by VANOS.

The camshafts are driven by a chain, and a vacuum pump driven by that chain feeds the brake booster.

Intake, fuel and engine management

The DISA intake manifold has three stages switched by two actuators. BMW's system overview lists six fuel injectors, six single-spark ignition coils, a secondary air pump and a heated crankcase ventilation. The MSV80 version uses active air-flap control on some models.

Oil and cooling

Because the VANOS units can call for a lot of oil, BMW fitted a pump that varies how much oil it delivers. There is no dipstick; an oil condition sensor reports the level instead.

The coolant pump is electric, controlled by the engine computer, and a map-controlled thermostat sits near it. BMW's training warns the pump bearings are lubricated by coolant and must not run dry.

Variants and labels

In BMW's engine code, B25 and B30 are the 2.5 and 3.0 liter sizes and OL means upper output stage. The first-series N52 uses MSV70; the modified N52 uses MSV80. BMW's parts data labels the later cars N52N. BMW's recall bulletins use N52K and N52T. No document opened says how N52N, N52K and N52T relate to each other, so they are not equated here.

The N51 is a separate label. BMW's parts data lists N51 types next to N52N types on the US 128i and 328i, and the electric coolant pump, oil pump and eccentric shaft numbers below are listed for N51 as well.

Service Parts at a Glance

Numbers below are BMW's current numbers, each looked up in BMW's parts data. Several parts are shared with other engines, as noted. Confirm fitment by VIN before ordering.

Part	BMW part number	Note
Oil filter element set	11427953129	Replaces 11428683196, which was discontinued in September 2017. Also listed for N51, N54, N55, N20 and N26 types.
Spark plug	12122158253	Six per engine. Listed for N52, N52N and N51 only. Later cars also list 12120037663.
Spark plug (later N52N cars)	12120037663	NGK LZFR6AP11GS in the parts data.
Ignition coil	12138616153	Listed for many other BMW engines as well. One single-spark coil per cylinder.
Electric coolant pump	11517586925	Listed for N52, N52N and N51 only.
Thermostat	11537549476	Also listed for N54 types.
Oil pump	11417545939	Listed for N52, N52N and N51 only.
Eccentric shaft (Valvetronic)	11377515868	Listed for N52, N52N and N51 only.
Eccentric shaft sensor	11377524879	Listed for N52, N52N and N51 only.
Cylinder head cover, first-series N52	11127548274	Listed for the N52 label only (E60, E61, E90, E91, E85, E86).
Cylinder head cover, N52N and N51	11127552281	Listed for N52N, N51 and a few N52 rows.
Air filter element	13717542294	Listed for N52, N52N and N51.
Ribbed belt 6PK1990	11287628650	Listed for N52, N52N and N51.
Belt tensioner	11288624196	Listed for N52, N52N and N51.

Known Failure Points and Service Items

Only items backed by a recall or a BMW bulletin are listed. Recall information was checked against NHTSA on October 1, 2026. Recalls change, and whether a specific car is covered is a VIN check with BMW or NHTSA.

01 Crankcase ventilation (PCV) valve heater

BMW's training says the N52 crankcase ventilation is heated and switched by the engine computer through a relay.

NHTSA lists recall 17V-683 (October 2017) for a PCV valve heater that may short circuit, with melting parts in the valve and a fire risk even when the car is not in use. BMW's bulletin SI B11 16 17 says the affected models have a N51, N52, N52K or N52T engine and about 740,561 vehicles.

Recall 19V-273 (April 2019) expanded it to 2006 models, and recall 22V-119 (March 2022) supersedes and expands both. BMW's report for 22V-119 lists 917,106 potentially involved vehicles, and the remedy is a wiring harness with fuse protection for the heater. Bulletin SIB 11 01 22 (revision 4, August 2022) names the engines N52 and N52K, with N51, and says the N52T is no longer affected.

Watch for: the check engine light, smoke near the engine compartment, or a burning-plastic smell. BMW's report for 22V-119 lists these as the warnings that can occur, and BMW's 2017 owner notice says to stop driving if smoke or that smell appears. Check the VIN for an open campaign either way. Cars repaired under the 2017 or 2019 recalls need to come back for the 2022 remedy.

02 VANOS housing bolts

NHTSA lists recall 14V-176 (April 2014) for aluminum bolts that secure the VANOS housing and can loosen or break. BMW's bulletin SI B11 07 14 covers N51, N52K and N52T engines built from September 2009 to November 2011 in the E70, E82, E83, E88, E89, E90, E91, E92, E93, F10 and F25.

Recall 23V-707 (October 2023) covers the VANOS housing bolts again, on cars built between September 2, 2009 and July 12, 2012, and BMW's bulletin SIB 11 09 23 names the N51, N52K, N52T and N55 engines. BMW's November 2023 report gave 155,627 potentially involved vehicles (NHTSA's current record lists 157,796), and the bulletin says these cars were earlier covered by a 10 year, unlimited mileage warranty extension for the VANOS adjustment units (SI B01 10 14).

Cars whose two VANOS units (11 36 7 583 207 and 11 36 7 583 208) or whole engine were replaced on or after September 1, 2012 are listed as unaffected.

BMW says a driver sees the Check Engine light and a message for reduced engine power, hears more engine noise, and in rare cases the engine will not restart or stalls.

Watch for: the reduced-power warning, a rougher or noisier engine, or a no-start after shutting the engine off. Treat any of them as a reason to check the VIN for the open campaign before buying parts.

Reliability Verdict

Not established yet. We are still researching this engine. BMW's documents give two recall families that name N52-family hardware (the PCV valve heater and the VANOS housing bolts), listed above, and no failure rates.

IAIK, from our own shop, finds the N52 unusually tolerant of neglect, including cars that went 20,000 miles without an oil change. That is IAIK shop experience, not a failure rate or a maintenance recommendation.

IAIK has also seen four all-wheel-drive N52 cars above 400,000 miles in our shop, and rates the N52 as its pick for daily-driver reliability.

Power Potential

Not established yet. BMW's factory output figures for US cars are in Technical Specifications. No BMW document gives a safe tuning limit.

Cost of Ownership

Not established yet. No BMW document gives a repair cost, a service interval for the electric coolant pump, or a replacement mileage for any N52 part.

Common Questions

What BMW cars have the N52 engine in the US?

BMW's parts data lists the N52 or N52N in the US-catalog 325i, 328i, 330i, 128i, 525i, 528i, 530i, Z4 3.0i, Z4 3.0si, Z4 sDrive30i, X3 3.0i, X3 3.0si, X3 xDrive28i and X5 3.0si, built between March 2005 and October 2013.

How much oil does an N52 take?

BMW's technical data lists 6.5 liters (about 6.9 US quarts) for an oil change with the filter on the N52B25 and N52B30.

What is the N52 engine block made of?

BMW's training describes the N52 crankcase as magnesium alloy cast around an aluminum-silicon insert, with a separate magnesium bedplate.

Does the N52 have a timing belt or a timing chain?

BMW's training describes a chain drive for the camshafts, and BMW's parts data lists a timing chain and chain tensioner for N52 and N52N cars.

What is the N52 firing order?

BMW's training lists the N52 firing order as 1-5-3-6-2-4.

Has the N52 been recalled?

Yes. BMW has recall campaigns for the PCV valve heater (NHTSA 17V-683, 19V-273 and 22V-119) and for the VANOS housing bolts (14V-176 and 23V-707), which name N52-family engines in its own bulletins. Check the VIN with BMW or NHTSA to see whether a car is covered.