Bulletin
Engine code

IA Technical Bulletin

BMW M52 Engine Guide

Engine: M52

Bulletin text

The M52 is BMW's inline-6 that sits between the M50 and the M54. In BMW's training, the M52TU ('technically updated') is the evolution of the M52 from the E36 and E39, built in 2.5 and 2.8 liter sizes. The name covers two generations that are not the same engine: the original M52 and the M52TU.

Original M52: single VANOS, with a block material that depends on market and car (see Factory Deep Dive); BMW's training says the M52TU moved to an aluminum crankcase 51 lbs lighter than the cast iron block of the M52.
M52TU: double VANOS, Siemens MS42.0 engine management, a redesigned aluminum crankcase and a new cooling system; in the E46 BMW's training gives production dates of 6/98-6/00 (M52TUB28) and 6/98-9/00 (M52TUB25).

BMW sold the M52 and M52TU in US-market cars. This page says which generation each statement applies to. The M52TU's successor, the M54, and the US-only M56 have their own guides.

Quick read

Ownership position: Not established yet. We are still researching this engine.
Reliability: Not established yet. BMW's service bulletins below cover specific, dated items for each generation; none of them is an engine-wide rating.
Cost to own: Not established yet. We are still researching this engine.
Power potential: Not established yet. No BMW document we opened gives a tuning limit; factory output is in Technical Specifications.
Main watch item: Crankcase ventilation return line on the M52TU built 11/1998-2/2000 (BMW service bulletin 11 06 02).

M52 At a Glance

Question	Practical answer
Sold in US-market BMWs?	Yes. BMW's US-specification parts data lists the M52 in the cars under Where you find it.
Generations	Original M52 (E36, E39, Z3 2.8) and M52TU (E46, E39 from 1998, Z3 from 1998).
Factory output	BMW's training gives 126 kW (170 hp) at 5,500 rpm for the M52TUB25 and 125 kW (168 hp) at 5,500 rpm for the original M52B25. For the 2.8 liter it gives 144 kW (193 hp) at 5,500 rpm for the M52TUB28 and 142 kW (190 hp) at 5,300 rpm for the M52B28.
Block	BMW's training describes an aluminum crankcase for the M52TU that is 51 lbs lighter than the cast iron block of the M52.
Engine oil	BMW's February 2017 oil chart (SI B11 01 15) lists 5W-30 LL01 or 0W-30 LL01FE for all BMW gasoline engines of model year 2011 and older.
Oil capacity	BMW's fluid data lists 6.5 liters for US M52 and M52TU cars.
Oil consumption allowance	BMW's SI B11 03 13 says all BMW engines except Motorsport engines can use up to 1 quart of oil per 750 miles at any time.
Recalls tied to M52 cars	Not established yet. We did not find an engine-specific NHTSA recall for US M52 or M52TU cars; see Known Failure Points.
Reliability profile	Not established yet. We are still researching this engine.
Typical annual planning budget	Not established yet. We are still researching this engine.
Common tuned street range	Not established yet. We are still researching this engine.
Before buying	Confirm whether the car has the original M52 or the M52TU, then ask a BMW dealer to check your VIN for open recalls.

Where you find it

BMW's US-specification parts data lists the M52 and M52TU in the chassis below. The parts data ends in December 2019 and shows catalog build dates, which can start before US sales.

Chassis	US model, body, generation and build dates (BMW parts catalog)
E36	323i convertible (M52), built 9/1997-9/1999
E36	323i coupe (M52), built 9/1997-5/1999
E36	328i convertible (M52), built 11/1995-9/1999
E36	328i coupe (M52), built 11/1995-4/1999
E36	328i sedan (M52), built 11/1995-4/1998
E39	528i sedan (M52), built 3/1996-9/1998
E39	528i sedan (M52TU), built 9/1998-8/2000
E39	528i wagon (M52TU), built 9/1998-8/2000
E46	323Ci convertible (M52TU), built 12/1999-8/2000
E46	323Ci coupe (M52TU), built 6/1999-8/2000
E46	323i sedan (M52TU), built 7/1998-10/2000
E46	323i wagon (M52TU), built 2/2000-9/2000
E46	328Ci coupe (M52TU), built 6/1999-5/2000
E46	328i sedan (M52TU), built 6/1998-5/2000
Z3	Z3 2.5 roadster (M52TU), built 9/1998-9/2000
Z3	Z3 2.8 coupe (M52TU), built 9/1998-12/1999
Z3	Z3 2.8 roadster (M52), built 11/1996-9/1998
Z3	Z3 2.8 roadster (M52TU), built 9/1998-6/2000

BMW's service information names the original M52 B28 in US E36 (except Z3) and E39 cars, and BMW's E46 training covers the 323i and 328i with the M52TU in 2.5 and 2.8 liter versions. In the E46, BMW's training gives M52TU production dates of 6/98-6/00 (B28) and 6/98-9/00 (B25). Where one model spans both generations, the split in the table follows the change of coolant pump part number in BMW's parts data at 9/1998.

Technical Specifications

Specification	Detail
Configuration	Six cylinders in line.
Displacement and bore x stroke (original M52)	Wikipedia lists the M52B25 at 2,494 cc (84 x 75 mm) and the M52B28 at 2,793 cc (84 x 84 mm).
Compression ratio (original M52)	Wikipedia lists 10.5:1 for the M52B25 and 10.2:1 for the M52B28.
Output, M52TU	M52TUB25: 126 kW (170 hp) at 5,500 rpm and 245 Nm at 3,500 rpm, per BMW's training.
Output, original M52	M52B25: 125 kW (168 hp) at 5,500 rpm and 245 Nm at 3,950 rpm, per BMW's training.
Output, 2.8 liter	M52TUB28: 144 kW (193 hp) at 5,500 rpm and 280 Nm at 3,500 rpm. M52B28: 142 kW (190 hp) at 5,300 rpm and 280 Nm at 3,950 rpm. Both per BMW's training.
Block, original M52	BMW's service information says Euro-market (ECE) M52 engines had aluminum blocks with Nikasil-coated cylinder bores before a 1998 changeover; it also lists special engines with a solid cast iron block (option 961) for certain countries.
Block, M52TU	Aluminum crankcase with cast iron liners, boreable once (+0.25 mm), per BMW's training.
Crankshaft, M52TU	Cast iron on the 2.5 liter and forged steel on the 2.8 liter, both mass balanced, with seven main bearings.
Pistons and rods, M52TU	Pistons carry over from the M52 (graphite-coated skirts on the 2.8 liter) and the connecting rods are forged steel.
Valvetrain	The original M52 has a single VANOS system that works as a simple on/off system; the M52TU has double VANOS with continuously adjustable intake and exhaust camshafts.
Engine management	M52TU: Siemens MS42.0. BMW service information for US M52 cars refers to DME MS 41.1 and MS 41.2.
Intake, M52TU	A molded plastic intake manifold with resonance charging and turbulence bores.
Cooling, M52TU	A partial engine cooling concept with coolant fed directly to the cylinder head, and a map-controlled heated thermostat.
Exhaust, M52TU	Catalytic converters built into the exhaust manifolds.
Emissions, M52TU	Developed to meet the LEV standard.
Timing drive	BMW's parts catalog lists a timing chain (11 31 1 432 176) and chain tensioner (11 31 1 703 717) for the M52.
Engine oil	5W-30 LL01 or 0W-30 LL01FE (BMW February 2017 oil chart, model year 2011 and older).
Oil capacity	See At a Glance.
Firing order	Not established yet. We are still researching this engine.

Factory Deep Dive

Block: iron, aluminum and market

BMW's training says the M52TU crankcase is a new design in the same aluminum alloy as the crankcase of the 2.8 liter M52 in the Z3, and that it is 51 lbs lighter than the cast iron block of the M52. BMW's service information also lists special M52 engines with a solid cast iron block (option 961) for certain country variants. Which US-market M52 cars, other than the Z3 2.8, have a cast iron block is not established from a BMW document that names them.

For the Euro-market M52, BMW service information says aluminum blocks with Nikasil bores were changed over to aluminum blocks with cast iron cylinder liners from March 1998, finishing worldwide in September 1998, and that the M52TU has the cast iron liners from series launch.

Original M52 and the M52TU: what changed

BMW's training lists these changes from the M52 to the M52TU: a redesigned crankcase, modified crankshaft and pistons, an oil pump and pressure regulator built into the oil sump deflector, double VANOS, a redesigned cooling system with a map-controlled thermostat and quick-disconnect hoses, a motor-driven throttle valve and catalytic converters in the exhaust manifold. The stated goals were lower fuel consumption and emissions with more power and a better torque curve.

Double VANOS on the M52TU

According to BMW's training, double VANOS came from the European M3 engine, and the M52TU got a version made for series production. The rest position is intake camshaft retarded and exhaust camshaft advanced, and BMW's training says the camshafts also stay there if the electronic control fails.

Cooling on the M52TU

BMW's training says the M52TU cooling system aims to keep the cylinder head cooler for torque and the crankcase warmer for lower friction, and that coolant to the block is metered through holes in the head gasket.

Service Parts at a Glance

Part	BMW part number (current)	Note
Spark plug, High Power	12 12 0 037 607	Current; BMW's replacement for 12 12 9 071 003; listed for M50, M52, M54 and M56 cars.
Spark plug	12 12 9 064 617	Current; listed for M50 and M52 cars built to 9/1997.
Ignition coil	12 13 7 599 219	Current; listed for M52 and M54 cars (replaces 12 13 1 748 018).
Coolant pump (mechanical), original M52	11 51 7 527 799	Current; listed for M50 and original M52 cars built to 9/1998.
Coolant pump (mechanical), M52TU	11 51 7 509 985	Current; listed for M52TU, M54 and M56 cars.
Thermostat (original M52)	11 53 7 511 083	Current; listed for M50 and original M52 cars.
Thermostat housing with thermostat (M52TU)	11 53 7 509 227	Current; listed for M52TU, M54 and M56 cars.
Cylinder head cover (M52TU)	11 12 1 432 928	Current; listed for M52TU and M54 cars.
Oil filter element set	11 42 7 512 300	Current; BMW's supersession chain runs from 11 42 1 427 908 to this number; listed for M52, M54 and M56 cars.
Timing chain	11 31 1 432 176	Current; also listed for M50, M54 and M56 cars.

A matching part number locates a part; it does not confirm that it fits a specific VIN.

Known Failure Points and Service Items

Recall information on this page was checked against NHTSA on October 1, 2026. Recalls are added and closed over time. Whether a specific car is covered is a VIN check with BMW or NHTSA. We did not find an engine-specific NHTSA recall for US M52 or M52TU cars, which is a limit of our search and not a clean bill of health.

01 Cylinder liner wear on the Euro-market M52 (service bulletins 11 06 97, 11 07 98, 11 08 98)

BMW bulletins 11 06 97, 11 07 98 and 11 08 98 cover E36 (not Z3), E38 and E39 cars with the Euro-market (ECE) M52 whose block had Nikasil-coated bores. BMW says some fuels, high-sulphur fuel among them, can wear the cylinder bores, causing uneven idle, lost power and higher oil use. BMW's 11 08 98 bulletin treats confirmed liner damage as an engine replacement to an aluminum block with cast iron liners.

We have not found a BMW document that applies these bulletins to US-market M52 cars; the ones that name a market say ECE. Watch for uneven idle, loss of power and rising oil use on an imported Euro-market car.

02 Crankshaft sensor on US M52 cars (service bulletin 00 12 27 01)

BMW's bulletin covers US E36 M52 cars (not Z3) built to December 1998, US Z3 M52 cars built to September 1998 and US E39 M52 cars built to August 1998, fitted with a crankshaft sensor that can fail with thermal stress. BMW lists vibration, stalling, failure to start and a check engine lamp with crankshaft sensor fault codes as the effects, and converts the cars to the newer MS42-type sensor with an adapter lead.

Watch for stalling, a no-start or rough running with crankshaft sensor fault entries on a car in that production window.

03 Crankcase ventilation return line, M52TU (service bulletin 11 06 02)

BMW's bulletin covers the Z3, E46 and E39 with the M52TU built from November 1998 to February 2000. BMW says acidic condensate can eat holes in the bend of the crankcase ventilation return line, and the engine then draws in unmetered air; BMW lists idle problems, mixture depletion faults, the emergency program and, on US models, the Service Engine Soon light as results. BMW's fix is to check the line and replace it with a more chemically resistant version.

Watch for rough idle, a lean-mixture fault or a Service Engine Soon light on an M52TU car of those build dates.

04 Cylinder head cracks near cylinder 1, M52TU (service bulletin 11 01 99)

BMW's bulletin covers Z3, E38, E39 and E46 cars with the M52TU built from September 1999 to October 1999, whose cylinder head may have hairline cracks near cylinder 1. BMW describes coolant loss at cylinder 1 on the exhaust side near the chain tensioner and a coolant level message, and calls for a new cylinder head.

Watch for unexplained coolant loss, a coolant level warning or a rising temperature gauge on an M52TU built in that two-month window.

05 Fuel smell from the rear (service bulletin 16 01 01)

BMW service bulletin 16 01 01 covers the E46 with the M52TU (up to 11/98 and from 11/98 to 09/00) and describes a strong fuel smell after extended uphill driving or stop-and-go driving. BMW's answer is a service package for the fuel system at the rear of the car.

Watch for fuel smell near the rear of an E46 after long climbs or heavy traffic.

06 Valve train rattle after a cold start (service bulletin 11 10 98)

BMW's bulletin 11 10 98 covers M50, M52 and other engines with hydraulic valve clearance elements and says rattling right after a cold start is traced to the higher viscosity of cold oil. BMW says these noises do not shorten engine life.

Watch for rattling that stays after the engine is warm or follows a very low oil level.

07 Oil consumption and crankcase ventilation

BMW's oil consumption bulletin SI B11 03 13 says all BMW engines except Motorsport engines can use up to 1 quart of oil per 750 miles at any time. It lists maintenance, external leaks, overfilling, oil viscosity, engine speed and load, and a malfunctioning crankcase ventilation system among the causes to check before engine repairs.

Watch for oil use beyond that allowance, with an engine that is otherwise leak-free and correctly filled.

Reliability Verdict

Not established yet. We are still researching this engine. The bulletins above are narrow, dated items and none of them rates the M52 or M52TU as a whole.

Power Potential

Not established yet. We are still researching this engine. No BMW document we opened gives a tuning limit for the M52 or M52TU.

Cost of Ownership

Not established yet. We are still researching this engine. No BMW document gives repair costs or a service reserve.

Common Questions

What BMW has the M52 engine?

BMW's US-specification parts data lists the M52 in the E36 323i and 328i, E39 528i, E46 323i, 323Ci, 328i and 328Ci, and Z3 2.5 and 2.8, with the E46 cars and the later E39 and Z3 cars carrying the M52TU.

What is the difference between the M52 and the M52TU?

BMW's training says the M52TU has a redesigned crankcase, double VANOS instead of single VANOS, an oil pump built into the sump deflector, a redesigned cooling system with a map-controlled thermostat, a motor-driven throttle valve and catalytic converters in the exhaust manifold.

Does the M52 have an iron or aluminum block?

It depends on the generation and market: BMW's training describes the M52TU block as aluminum, the M52 block it replaced as cast iron and the Z3 2.8 M52 crankcase as aluminum, and BMW service information says Euro-market M52 engines had aluminum blocks with Nikasil bores until a 1998 changeover.

How much oil does an M52 take?

BMW's fluid data lists 6.5 liters for US M52 and M52TU cars.

Is the M52 chain-driven?

BMW's parts catalog lists a timing chain and a chain tensioner for the M52, and no timing belt.

Which engine is in the E46 323i and 328i?

BMW's E46 training covers the 323i and 328i with the M52TU in 2.5 and 2.8 liter versions, with production dates of 6/98-9/00 for the B25 and 6/98-6/00 for the B28.