The N47 is BMW's four-cylinder diesel (2.0 litres, plus a 1.6), fitted from 2007 until the B47 took over in 2014-2015 in the 1, 2, 3 and 5 Series, the X1, the X3 and the diesel Minis. Its best-known weakness is the timing chain at the back of the engine: it can wear early, worst on engines built from 2007 to early 2009, and replacing it usually means taking the engine out. Swirl flaps in the intake, leaking EGR coolers (covered by BMW recalls), a short-lived crankshaft pulley and injectors at high mileage are the other things to check. With a documented chain replacement and a quiet cold start it is a reasonable buy; without them, price the chain in.
At a glance
Displacement
2.0 L (1,995 cc), 4 cylinders; a 1.6 L (1,598 cc) version in some 1 Series and the Mini One D and Cooper D
Built
From 2007; replaced by the B47 from 2014-2015
Timing drive
Chains at the back of the engine, on the gearbox side
Power
About 95-218 PS; twin-turbo on the 23d and 25d
Injectors
Common rail: solenoid injectors on the lower outputs, piezo injectors on most versions from 163 PS
Related engines
The N57 is the 3.0-litre six-cylinder from the same family and the B47 is the 2.0-litre successor; neither is covered on this page
Cars with this engine
Make
Models
Years
BMW
1 Series: 116d, 118d, 120d, 123d (E81, E82, E87, E88); 114d to 125d (F20, F21 before the B47)
2007-2015
BMW
3 Series: 316d, 318d, 320d (E90, E91, E92, E93); 316d to 325d (F30, F31, F34 before the 2015 facelift)
2007-2015
BMW
5 Series: 520d (E60, E61 from late 2007); 518d, 520d, 525d (F10, F11)
2007-2014
BMW
2 Series: 218d, 220d, 225d (F22)
2014-2015
BMW
X1 (E84): sDrive18d to xDrive25d; X3: xDrive20d (E83), 18d and 20d (F25 before the B47)
2007-2015
Mini
One D and Cooper D (1.6, N47C16), Cooper SD (2.0, N47C20): hatch, Clubman, Convertible, Coupé, Roadster, Countryman, Paceman
2010-2016
Known problems
Timing chain wear at the back of the engine
What happens
The N47 drives its camshafts with chains at the back of the engine, on the gearbox side. Worn guides, a weak tensioner and, on early engines, a badly finished crankshaft sprocket let the chain stretch and grind; if it jumps or snaps, the valves hit the pistons and the engine is often beyond saving. Engines built from 2007 to early 2009 were hit hardest. BMW revised the parts, but later engines can still wear their chains at high mileage, and because of where the chain sits the engine normally has to come out to replace it.
Symptoms
Metallic rattle or grinding from the back of the engine, loudest for a few seconds after a cold start
Check-engine light with a crankshaft/camshaft correlation or camshaft sensor code
Loss of power or rough running
Engine cuts out, or will not restart after a short stop
When
Worst on engines built 2007 to early 2009; on later engines usually from about 100,000 km, sooner with long oil-change intervals
Fitted cost
from €1,500 to €2,500
The fix
Replace the complete chain set with the revised guides, tensioners and sprockets, normally with the engine out. If the chain has already jumped, the head or the whole engine needs rebuilding or replacing (roughly €2,000-6,000+).
Most 2.0-litre N47s have small swirl flaps inside the intake manifold. Soot from the EGR system builds up on them and the flaps and their mountings wear or crack; a piece that breaks off is drawn into a cylinder, where it damages the piston and valves and can reach the turbo. Workshops often remove the flaps as a precaution.
Symptoms
Uneven running, especially at idle
Loss of power
Misfire or low compression on one cylinder
When
Can start from about 70,000 km; the risk grows with mileage
Fitted cost
from €150 to €650
The fix
Fit a new intake manifold, or remove the flaps and seal the openings with blanking plugs (sometimes with a software change). A flap that has already entered the engine means a cylinder-head repair or an exchange engine.
The cooler that chills the recirculated exhaust gas can leak coolant into the EGR system. Mixed with soot at high temperature, it can form glowing deposits and, in rare cases, start a fire in the engine bay. BMW has recalled N47, N57, B47 and B57 diesels over this in several waves since 2018 and now fits a redesigned cooler from a different supplier, so ask a BMW dealer to check the VIN for open recall work.
Symptoms
Coolant level dropping with no visible leak
Sweet smell or white vapour from the exhaust
Burning smell from the engine bay (stop and switch off)
Check-engine light with an EGR code
When
Any age; the recalls cover a wide spread of production years, so check every car
Fitted cost
from €550 to €1,400
The fix
Where a recall applies, a BMW dealer replaces the cooler free of charge. Outside a recall, replace the EGR cooler and inspect the intake for soot and heat damage.
The pulley on the front of the crankshaft, which drives the auxiliary belt, has a built-in torsional vibration damper with a limited life. On the N47 it wears relatively quickly, and a worn damper makes the belt drive noisy and puts the auxiliary belt at risk.
Symptoms
Rumbling or knocking noise from the front of the engine
More vibration at idle
Cracked rubber or a wobble visible at the pulley
When
Higher mileage; check it at every purchase
Fitted cost
from €150 to €600
The fix
Replace the crankshaft pulley and check the auxiliary belt and its tensioner. Genuine parts cost more; the durability of cheaper replacements varies.
The N47 uses common-rail injectors: solenoid injectors on the lower outputs and piezo injectors on most versions from 163 PS. They wear with mileage, and a failing injector upsets combustion on its cylinder. The high-pressure pump does not like running on an almost empty tank, so a car that was often driven on reserve deserves extra care.
Symptoms
Rough idle or knocking from one cylinder
Smoke when accelerating
Hard starting
Check-engine light, sometimes with reduced power
When
Usually from about 150,000 km
Fitted cost
from €250 to €650
The fix
Test the injectors and replace or recondition the faulty ones; a new injector has to be coded to the engine control unit. A full set of four costs roughly €800-1,600.
+Stored and pending engine codes such as P0016, P0017, P0340 and P0341 (crankshaft and camshaft timing), the P0300-P0304 misfire codes and P0401 (EGR flow)
+Diesel particulate filter codes such as P2002, P244A and P244B, and rail pressure codes such as P0087
+The freeze-frame snapshot saved with a code: rpm, load, coolant temperature and speed at the moment it set
+Live coolant temperature, to spot a car that loses coolant or never warms up properly
+Live intake manifold pressure (MAP) and airflow (MAF), which show whether the engine builds boost and breathes normally
+Readiness monitors: several incomplete monitors on a car for sale suggest the codes were cleared recently
Needs manufacturer-level software
−How far the timing chain has stretched before a timing code sets: that takes a cold-start listen or a workshop inspection
−Swirl flap position and condition, or EGR valve commanded versus actual position, which need BMW-specific software
−Soot load in grams, regeneration count and time since the last regeneration of the particulate filter (manufacturer-extended data)
−Per-cylinder injector correction values, which need BMW software such as ISTA or a BMW-capable app
−Whether the EGR cooler recall work has been done: a BMW dealer checks that on the VIN
−The condition of the crankshaft pulley, which needs a visual check
Buying checklist
Confirm the engine: the B47 replaced the N47 from 2014-2015, so on a 2014 or 2015 car check the engine code in the documents or on the engine rather than trusting the model year.
Start the engine fully cold (parked overnight, bonnet cold) and listen at the back of the engine for a metallic rattle in the first seconds.
Ask for an invoice for a timing chain replacement with date and mileage; with an original chain at high mileage, take the job off the price.
Ask whether the swirl flaps have been replaced or removed, and look for the invoice.
Ask a BMW dealer to check the VIN for open EGR cooler recall work, and check that the coolant level is where it should be.
Look for oil changes every 10,000-15,000 km rather than long-life intervals, which are hard on the chain.
Read stored and pending codes and the readiness monitors before the test drive.
With the engine idling, look and listen at the crankshaft pulley at the front for noise, cracks or a wobble.
Checking a car with this engine?
The Skanyx pre-purchase check guides you through 15 minutes at the seller's car and gives a 0-100 score, a Buy, Negotiate or Walk Away verdict, and what the repairs should cost.
Already driving one? Read its fault codes with the free app. Get the Skanyx app
Frequently asked questions
Is the BMW N47 a reliable engine?
It is economical and strong, but its timing chain gives it a poor reputation. Engines built from 2007 to early 2009 are the most at risk; later ones were improved but can still wear their chain at high mileage. With a documented chain replacement, regular oil changes and the EGR cooler recall done, an N47 can cover high mileage.
Which N47 years have the timing chain problem?
The worst affected engines were built between March 2007 and January 2009. BMW revised the chain parts from 2009, and failures became less frequent, but chains on later N47 engines built up to 2015 can still stretch, usually at higher mileage.
Where is the timing chain on the N47 and how do I know it is worn?
It sits at the back of the engine, on the gearbox side, which is why the engine normally has to come out to replace it. The classic warning is a metallic rattle or grinding from the back of the engine for a few seconds after a cold start. A stretched chain can also set crankshaft/camshaft correlation codes such as P0016 or P0017.
How much does an N47 timing chain replacement cost?
At an independent workshop a full chain kit with guides and tensioners typically costs about €1,500-2,500 fitted, because the engine has to come out. Dealer bills are higher: AUTO BILD reported around €4,000 for the repair on early engines in 2013. If the chain has already jumped, a rebuilt or exchange engine costs roughly €2,000-6,000 or more.
Should the swirl flaps be removed on an N47?
Many workshops remove them as a precaution, because a flap that breaks off can wreck the engine; the alternative is a new intake manifold. Removal means blanking the openings and sometimes a software change, so have it done by a workshop that knows the N47 and check that the change is allowed where the car is registered.
What is the difference between the N47, N57 and B47?
The N47 is the four-cylinder 2.0-litre (and 1.6-litre) diesel built from 2007. The N57 is the 3.0-litre six-cylinder diesel from the same family, and the B47 is the 2.0-litre four-cylinder that replaced the N47 from 2014. The B47 also has its chain on the gearbox side, but chain failures on it are far less common and mostly appear at high mileage.
