BMW 320d (E46) engine: which one, problems and replacement

The BMW 320d in the fourth 3 Series generation (E46, built 1997–2006) was built with 2 different engines over its life: the M47D20 (136 hp, 1998–2007) and the M47TUD20 (150 hp, 2001–2007).

Below you will find how to identify the engine in your 320d, the faults to look for, current prices for a replacement and the swap options that make sense.

• Generation: fourth 3 Series, 1997–2006
• Body styles: E46 (saloon, Touring, coupé, convertible, Compact)
• Engines: M47D20, M47TUD20
• Output: 136 hp and 150 hp
• Replacement engines in stock: ask the desk for the next arrival

Which engine is in your 320d?

M47D20 in the 320d

The M47D20 was used in the E46 320d, built 1998–2007. It is a 2.0 L turbocharged diesel inline-4 with 136 hp and 280 Nm. Compared with the M47TUD20 (150 hp), it is the mildest.

Reading the code: M marks an M-series code, the naming BMW used for its engine families up to the early 2000s; 47 is the family number; D stands for diesel; 20 is the capacity in decilitres, so 2.0 litres.

M47TUD20 in the 320d

The M47TUD20 was used in the E46 320d, built 2001–2007. It is a 2.0 L turbocharged diesel inline-4 with 150 hp and 330 Nm. Compared with the M47D20 (136 hp), it is the strongest.

320d engines by model year

The engine changed once during the E46 run, in 2001. Changes usually come with BMW's mid-life update (LCI) or a new emissions standard, so a car registered early in a year can still have the older engine. The VIN settles it.

Other cars with the same engine as the 320d

A replacement engine does not have to come from another 320d. These models left the factory with the same engine code, so a unit from any of them is a candidate donor once the sump, mounts and ancillaries are matched to your car.

M47D20: BMW E39 520d.

M47TUD20: BMW E83 X3 2.0d, BMW E87 120d.

How to confirm your engine code

Because the 320d used more than one engine, the badge alone does not tell you which one your car has. The build date is the first clue; the VIN is the proof. Send us the last seven characters of the VIN and we read the engine code from BMW's records, or look for the code stamped on the block. How to find your BMW engine code.

Known 320d engine problems

The M47D20 and M47TUD20 in the 320d share the known weak points of the M47 family. Full M47 guide.

Swirl flaps. The swirl flaps in the intake manifold can loosen and break, and a broken flap can enter a cylinder and destroy the engine.

EGR valve and cooler. The EGR valve clogs with soot and the cooler can leak.

Injectors. Common-rail injectors leak or fail.

Turbocharger. Turbos wear and leak oil.

Glow plugs. Glow plugs fail and cause hard cold starts.

Symptoms to watch for on the 320d

Rattle for a few seconds after a cold start. The classic sign of a weak timing chain tensioner or stretched chain. It must be checked quickly: a chain that jumps a tooth can bend valves.

Whistle, loss of boost or limp mode. A split charge pipe, a sticking wastegate or worn turbo bearings. Check the pipes first, then the turbo shaft for play.

Black smoke under acceleration. Too much fuel for the air available: boost leaks, a sticking EGR valve, a dirty air mass meter or a leaking injector.

Hard starting when cold. Glow plugs or the glow plug control unit. On older diesels, also check the injection pump and fuel lines for air leaks.

Sudden metallic noise followed by misfire. On diesels with swirl flaps, a broken flap or screw can enter a cylinder. Stop the engine immediately; continued running usually destroys the piston and head.

Looking after the 320d engine

• Oil: 5W-30 BMW Longlife-04, about 5.25 litres.
• Service interval: Oil every 10,000 to 15,000 km.
• Timing drive: Timing chain at the front.
• Workshop notes: Fit swirl flap blanks and clean the intake when installing a used M47.

Buying a used engine for the 320d: checklist

1. Why your old engine failed. Before fitting a replacement, find out why the original failed. An overheating radiator, a blocked intercooler or a failed turbo can destroy a second engine if they are not fixed.
2. List of what is fitted. Engines are sold with different ancillaries: some have the turbo, injectors, manifolds, alternator and starter, others are long blocks. Agree the list in writing so you know which parts must come from your old engine.
3. Sump, oil pickup and drive variants. Rear-drive, xDrive and front-drive cars can use different sumps, oil pickups and engine mounts even with the same engine code. Check that the sump matches your subframe and front axle.
4. Warranty terms in writing. Read what the warranty covers, how long it runs and what fitting conditions apply. Most warranties require a qualified workshop, new fluids and filters, and replacement of the cooling parts that caused the original failure.
5. Photographs from every side. Good suppliers photograph the actual engine you will receive. Look for the block stamp, the sump, the timing cover and any broken brackets or connectors in the pictures.
6. Turbocharger shaft play and oil. Rotate the compressor wheel by hand. A small amount of side play is normal; in-and-out play or wheel contact with the housing is not. Oil pooled in the intake or intercooler pipes points to worn seals.
7. Injector correction values. On a diesel that can be run before removal, the injector correction values show whether one injector is delivering more or less fuel than the others. Large deviations mean an injector is on its way out.
8. Swirl flaps. Check whether the swirl flaps are in place, blanked or removed. Broken swirl flaps are a known cause of engine failure on several BMW diesels, so many owners fit blanking plates when the intake is off.
9. Timing chain noise. Listen for a rattle at the front of the engine for the first seconds after a cold start. On an engine that cannot be run, look at the chain guides through the oil filler or with the valve cover off.

BMW 320d replacement engine cost

We do not have a 320d engine on the shelf at the moment. Send us your VIN or the code you need and the desk will tell you when the next unit arrives and what it will cost.

On top of the engine, budget for the workshop's labour and the parts that are best replaced while the engine is out: engine mounts, the rear main seal, cooling parts, a clutch or converter seal, fluids and filters.

Will it fit my 320d?

Will the M47D20 fit my BMW E46 320d?

The M47D20 is the original engine for the BMW E46 320d, which makes it the straightforward choice. The fourth 3 Series was built 1997–2006, and the M47D20 was produced 1998–2007, so check that your car's build date falls inside that window. Confirm the drive type (rear-drive or xDrive), the gearbox (manual or automatic) and the emissions standard, because these can change the sump, the flywheel and the software. Send us the VIN and we check all of it for you.

How much is a replacement engine for a BMW E46 320d?

We do not have an M47D20 on the shelf for the E46 320d at the moment. Units arrive regularly; send us your VIN and we will tell you when the next one is ready and what it will cost, including delivery.

Will the M47TUD20 fit my BMW E46 320d?

The M47TUD20 is the original engine for the BMW E46 320d, which makes it the straightforward choice. The fourth 3 Series was built 1997–2006, and the M47TUD20 was produced 2001–2007, so check that your car's build date falls inside that window. Confirm the drive type (rear-drive or xDrive), the gearbox (manual or automatic) and the emissions standard, because these can change the sump, the flywheel and the software. Send us the VIN and we check all of it for you.

How much is a replacement engine for a BMW E46 320d?

We do not have an M47TUD20 on the shelf for the E46 320d at the moment. Units arrive regularly; send us your VIN and we will tell you when the next one is ready and what it will cost, including delivery.

Engine swaps and upgrades for the 320d

These engines were fitted to other versions of the E46 at the factory, which makes them the most practical upgrades: the body was designed around them and many parts are shared.

Can I fit the M57D25 in my 320d?

It is a conversion rather than a replacement: the M57D25 is an inline-6 and your M47TUD20 an inline-4, so mounts, sump, cooling, exhaust, wiring and the engine control unit all change. The gain is 13 hp and 20 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Can I fit the M52B25 in my 320d?

It is a full conversion: the M52B25 runs on petrol and the M47TUD20 on diesel, so the fuel system, wiring, engine control unit, instrument coding and usually the gearbox change too. The gain is 20 hp and 0 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Can I fit the M54B22 in my 320d?

It is a full conversion: the M54B22 runs on petrol and the M47TUD20 on diesel, so the fuel system, wiring, engine control unit, instrument coding and usually the gearbox change too. The gain is 20 hp and 0 Nm. In Germany and most of Europe an engine swap must be inspected and registered.

Fitting a replacement engine in the 320d

1. Inspect or replace the timing chain parts. Look at the guides and tensioner. On high-mileage engines, replacing them now costs far less than doing it later.
2. Prepare the turbo. Fit new oil feed and return seals, clean the intercooler and pipes of any oil or debris from the old engine, and prime the turbo with oil before starting.
3. Code the injectors and bleed the fuel. Enter the injector correction codes into the ECU, check the glow plugs and bleed the fuel system so the engine does not crank dry.
4. Fill with the right oil and prime it. Fill with new oil of the correct specification and a new filter. Crank with the fuel and ignition disabled until oil pressure builds.
5. Coding and adaptations. On modern BMWs, the engine ECU must be matched to the car's immobiliser (CAS, FEM or BDC). Reset adaptations, register the battery and clear faults with diagnostic software.
6. First start and leak check. Start the engine, let it idle and watch oil pressure, temperature and fault codes. Check for leaks and bleed the cooling system.
7. First 1,000 km. Drive gently for the first few hundred kilometres, vary the engine speed and avoid full load. Change the oil and filter after about 1,000 km to remove any assembly debris.

The full fitting and first-start procedure.

320d engine questions

How much is a replacement M47D20TU2 engine for a BMW E46 320d?

A used M47D20TU2 for the BMW E46 320d costs from about 1.050 € to 1.850 € in our yard. The price depends on the year, the mileage and the parts that come with the engine.

Shipping is a flat 249 € per order. It is added once at checkout and printed on the invoice, so there is no extra fee later. Inside the EU there is no import duty. Outside the EU, the receiver pays local duty and VAT.

A replacement engine is often much cheaper than rebuilding a damaged one, and much faster. The M47D20TU2 you buy is photographed and checked in Hamburg before it is listed.

Eligible engines come with a 12 months warranty from the delivery date. It covers internal mechanical failure under normal use and correct fitting by a qualified mechanic or workshop. Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M47 Engines · Search M47D20TU2 in the shop

Will the M47D20TU2 engine fit my BMW E46 320d?

Yes, if your BMW E46 320d was built with the M47D20TU2. BMW used this 2.0 liter (1,995 cc) diesel engine with 120 kW (163 HP) in the E46 320d from about 2001 to 2007.

In our records the M47D20TU2 is the engine for the E46 320d, which makes the match simple. Still, check the code on your old engine or send us your VIN.

Also tell us if your E46 has a manual or an automatic gearbox. The flywheel or the flex plate and some sensors depend on it.

Not sure? Send us your VIN and your gearbox code. We match the engine family, the year window and the parts on the engine before anything is reserved, and the check is free.

See all M47 Engines · Search M47D20TU2 in the shop

Can I put an M47D20 engine in my Defender 110?

Yes. We sell conversion kits that fit the M47D20 into the Defender 110. The kit replaces the 200Tdi and Td5, and works with the R380 and LT77.

You can buy the full package with an engine, or only the parts you need: complete conversion with engine, complete conversion, adapter plate, engine mount, wiring and ecu and cooling and exhaust.

A swap like this needs a skilled workshop. Mounts, the adapter, the wiring and the engine computer, the cooling and the exhaust all have to work together. Check your local road rules for engine swaps before you start.

Tell us your Defender 110's year and current set-up, and we suggest the right parts. You can reach the Hamburg desk by email at autowerkeengines@gmail.com, or by phone and WhatsApp on +49 15510 030835, Monday to Friday, 9:00 to 16:00 CET.

See all M47 Defender Conversion Kits · Conversion guide

Delivery, warranty and payment

Before a 320d engine leaves our Hamburg yard it is drained of oil and coolant, every opening is sealed, and it is strapped to a pallet and wrapped. We send photographs of the packed unit and the tracking details.

Delivery is door to door and included in the price. Most European addresses receive the engine within five to ten working days; Germany and its neighbours are usually faster.

A 12-month warranty covers eligible internal failure when the engine is fitted by a qualified workshop with new fluids and filters. You can pay by card, bank transfer or crypto and receive the invoice by email straight away.

All E46 engines · M47 engine guide · BMW 320d engines for sale · Send us your VIN