BMW 2.0d (N47) Turbo Repair and Rebuild — 1 Series, 3 Series, X1 and X3

This page is for owners and garages dealing with a failing turbocharger on a BMW 2.0 diesel that carries the N47 engine. It shows how to confirm that your car has one, which turbocharger the catalogue lists at each power output, what wears out inside it, where a turbo fault ends and an actuator fault begins, and what a rebuild or a replacement costs.

One Engine, Four Badges: Which N47 Is in Your BMW

The four models in this page’s title are only part of the list. Trade catalogues put N47 turbochargers on the 1, 2, 3, 4 and 5 Series, the X1 and the X3, in model years running mostly from 2007 to 2014.

A published fitment list for N47 and N47N engines names the bodies and badges it covers:

Read that as a starting point rather than a complete register. It belongs to a single product, so it covers the cars that product fits. Other listings also put the X3 20d on the N47, and the catalogue lists X3 N47 turbochargers from 2007, earlier than the F25 body, which one supplier dates from 2010.

The same list separates the original N47 from the updated N47N. Every F-series body in it carries the N47N, the facelifted E90-family 320d is listed as an N47N from March 2011, and the 316d and 318d in that body appear under both codes. For the turbocharger, that update decides less than you might expect: the part follows the output and the reference on the unit, as the next section shows.

The badge is shared with other engines

This is where the model name starts to mislead. A 320d has been built with three different four-cylinder diesels, and the catalogue files all of them under one heading. Our own listing for the 3 Series 2.0 diesel carries M47 engine codes from the older engine, N47 codes, and B47 codes from the engine that followed, side by side. Parts retailers do the same, with 320d turbochargers for the M47, the N47 and the B47 on a single page.

The catalogue even lists B47 references in some of the same model years as N47 ones. So a 320d of a given year is not proof of an N47, and nothing on this page should be used to order a part for an M47 or a B47. Those turbochargers come to us through exactly the same mail-in service, but their references are different.

How to narrow it down before anything comes off

• The power output. Your V5C logbook gives it in kilowatts at section P.2. Multiply by about 1.34 for brake horsepower, the unit the catalogue uses. The next section shows why this one figure narrows the search so far.
• The registration. Put it on the Repair Form, so the car can be identified alongside the unit.
• The label on the turbo. Once the turbocharger is off, the label on its housing carries the reference that settles the question. Photograph it before the unit is cleaned or packed.

The Turbochargers Fitted to the N47, by Output

Search for an N47 turbo and you could conclude the engine has one. It does not. Taking only the N47 and N47N rows in trade catalogue data for these seven models, the engine is listed with more than half a dozen turbocharger designs, and what separates them most clearly is the power output the car was sold with.

The full reference list for each model, year by year and output by output, sits on the Affected Part Numbers tab of our rebuild listings for the 2 Series, 4 Series and 5 Series, as well as the four models in the quick facts above. Each listing covers its model’s 2.0 diesel years, the N47 among them, so it goes further than this page needs to.

The middle band: the Mitsubishi TF035

Between 161 and 197 bhp, the band that published listings attach to the 120d, 320d and 520d and to the X1 and X3 20d, the catalogue is dominated by the Mitsubishi TF035HL6. It comes in two broad versions. The 13TB references, in the 49135-05 and 49335-004 series, sit on most of the earlier rows; the 09GFT references, from 49335-005 onwards, sit on most rows from 2010.

Across these models the TF035 alone runs to more than twenty references. They look alike from the outside and they are not interchangeable, which is the whole difficulty with ordering one by description.

The top band: two turbochargers, not one

From 201 bhp upwards the catalogue changes shape. Some rows list a single entry described as a KP35 plus a K16. Others, on the N47D20T1 and N47D20D engines, list a BV35 and a K16 against the same engine, each with its own BMW number.

If the power on your V5C falls in that band, tell us on the Repair Form before anything is removed. The turbocharger on your engine may be a two-turbo arrangement rather than a single unit, and we will tell you what to send.

Where the bands blur

The bands are a way into the list, not a substitute for the label. Some combined catalogue rows put a TF035 reference against outputs as low as 134 bhp, and two RHV4 references are also listed at 174 bhp. A power figure near a band edge narrows the search; it does not finish it.

The label does. Turbo references on these units take forms such as 49135-05830, 767378-0010, 781232103 or 5435-970-0038, and BMW’s own part numbers for them, written in full, begin 1165, as in 11658519476. If the label has burned off or is unreadable, send the unit anyway: it is identified on the bench before any work starts.

One boundary: this page is about rebuilding the turbocharger your car was built with, to its original specification. Two of the leading results for this search sell hybrid or upgrade turbochargers for the N47. Those are a different job, and nothing here covers them.

What Fails Inside an N47 Turbocharger

Whatever the designation, each of these turbos is a turbine wheel and a compressor wheel on one shaft. Exhaust gas spins the turbine, the shaft turns the compressor, and the compressor pushes air into the engine. The shaft runs inside a centre bearing housing on a film of pressurised engine oil, with a seal at each end holding that oil in.

Most TF035 references carry a VG suffix in the catalogue. They are variable-geometry units, with a ring of vanes in the turbine housing that an electronic actuator moves to control boost, and that mechanism is one more thing that can stick.

The bearings, seals and thrust parts are designed to wear. The housings, wheels and shaft are meant to last the life of the turbo, and in most failed units they still can. When an N47 turbo fails, the damage usually runs in this order:

1. Bearings. The first parts to go, and the first to suffer when oil is short, overdue for a change or contaminated. A worn bearing lets the shaft move further than it was built to.
2. Seals. A shaft that no longer runs true stops the seals doing their job, so oil escapes into the intake on one side and the exhaust on the other.
3. Wheels. With enough movement a wheel touches its housing. A compressor wheel that has rubbed can shed fragments into the intake, and it is replaced rather than repaired.
4. Shaft. Left running on failed bearings, the shaft can bend or snap. The turbine wheel and shaft come as one assembly, so damage to either replaces both.
5. The vane mechanism. Carbon builds up around the vane pivots until the ring stops moving freely. That shows as a boost fault even when nothing in the rotating assembly has worn.

The size of the repair is decided mostly by how long the turbo kept running after the first sign of trouble. Taken off when it first starts to whine, an N47 unit is usually a bearings-and-seals rebuild. Driven on until it is blowing oil, it may need a wheel, the shaft or a housing as well.

Every one of those failures starts outside the turbocharger. Oil supply, oil condition and anything drawn into the intake are all things on the car, which is why the oil feed and return lines are renewed rather than reused at refit, and why the feed is primed before the first start. Our guide to common turbocharger problems sorts each symptom by where in the unit it starts and lists the cheaper faults that imitate a failed turbo.

Turbo or Actuator? Where the Line Falls on a BMW 2.0d

On an N47 with a variable-geometry turbo, two separate repairs sit on one assembly. The turbocharger is the rotating machine. The electronic actuator is the motor-and-gear unit on its side that positions the vanes. Either can put the car into reduced power, and they are not fixed the same way.

The evidence usually leans one way or the other:

• Towards the turbo itself: a metallic whine or siren that rises with engine speed; blue or grey smoke and oil use between services; oil pooled in the intake pipework after the turbo; movement you can feel at the compressor nut with the intake pipe off; or marks where a wheel has touched its housing.
• Towards the actuator: a boost fault that clears when the engine is restarted and then comes back, often worse, with no oil loss and no mechanical noise from the rotating assembly.
• Towards neither yet: an underboost or overboost code on its own. It records a pressure disagreement, not a part, and a split hose can store the same code.

If the evidence points at the actuator alone, the turbo does not need rebuilding. An electronic actuator is its own repair, from £100, and our pages for the BMW 3 Series actuator repair, the BMW 5 Series actuator repair and the BMW X3 2.0d actuator repair cover how to identify the unit and what its rebuild involves.

If the evidence points at the turbocharger, send it complete, with the actuator still attached, and say on the form whether you want the actuator assessed as well. Stiff vanes wear an actuator out, and a failing actuator can make a sound turbo look faulty, so the two are best judged together once the unit is on the bench.

Rebuild Your Own Turbo or Fit a Replacement?

The labour on the car is the same either way. The turbo comes off, a turbo goes back on, and the oil feed is primed before the engine first runs. The only real choice is which unit goes back, and it can wait until the old one is off.

A replacement has to be matched, and on the N47 that is harder than on most engines. Ordered as a “320d turbo”, it could be an M47, N47 or B47 unit. Ordered as an “N47 turbo”, it could still be any of more than twenty TF035 references, before counting the other designations. Only the reference on your own unit is a safe basis for buying one.

A rebuild has nothing to match. The unit that goes back is the one that came off, so its designation, reference and setting are already your car’s own. That is the sensible default whenever the housings, shaft and wheels pass inspection, because the parts that wore out are the ones designed to be renewed.

Replacement becomes the better value when too much has gone at once. A turbo needing new wheels, a new shaft and a new housing on top of its wear parts has very little of the original left. The strip decides that, and when a unit is not worth rebuilding we say so and recommend replacement instead.

What a BMW Turbo Replacement Costs

Our published prices start from three floors:

• Rebuild of your own turbocharger: from £185.
• Replacement turbocharger from us, reconditioned or new exchange: from £450.
• Electronic actuator repair on its own: from £100.

Our price guide names the BMW 3 Series in its mid-size row, where rebuilds of your own turbo run from £185 to £350 excluding VAT, against a typical market price of £900 to £1,300 for a new turbocharger. Where your rebuild falls in that range depends on what survived inside: a bearings-and-seals job sits near the bottom, and every wheel, shaft or housing that fails inspection moves it up.

The same logic holds for the 1 Series, X1 and X3. The catalogue fits them with turbochargers drawn from the same list as the 3 Series, so it is the condition of the unit rather than the body style that moves the price. The full breakdown, vehicle class by vehicle class, is in our guide to turbo repair prices.

Three things sit outside those figures. Labour to remove and refit the turbo is charged by whoever does it. The parts fitted with it, such as gaskets, an oil feed pipe, fresh oil and a filter, are separate. And whatever caused the first failure still needs finding and fixing on the car.

If you already know your car’s year and power output, you can order the rebuild directly from the listing for your model, with the price set for your car. The unit is still identified on the bench before any work starts, and your price is confirmed after inspection.

Our BMW N47 Turbo Rebuild

You, or the garage working on the car, take the turbocharger off and post it to us; we rebuild it and post it back. This is how it runs:

1. Complete the online Repair Form with the registration, the power output from the V5C, the mileage, the symptoms, any fault codes, and the reference from the turbo’s label if you can read it. If the output is 201 bhp or more, say so before you remove anything.
2. Remove the turbo. Our guide to removing and refitting a turbocharger covers the job, including priming on the first start.
3. Pack and post it complete, actuator attached and every port covered, to Unit 102 Reaver House, 12 East Street, Epsom, Surrey, KT17 1HX, United Kingdom. Packing and postage are covered on our FAQs page.
4. Identification and strip. The unit is identified from its label, or on the bench if the label is gone, then stripped to component level by specialists who rebuild turbochargers and turbo actuators as their core work.
5. Measurement and rebuild. The shaft, wheels, bearing surfaces and housings are cleaned and measured against original specification. Bearings, seals and thrust parts are renewed with genuine OE or OEM-grade components that meet or exceed the original, a part with a known design weakness is uprated rather than reinstated, and a wheel, shaft or housing that fails inspection is replaced as a section.
6. The vane mechanism freed or renewed. Cleaned and freed where its parts are sound, renewed where they are worn, so the vanes sweep as they were designed to.
7. Balanced, bench-tested and returned. The rotating assembly is balanced, the unit is set up and run on the bench, then boxed and posted back ready to refit.

Bench time is typically one to three working days from arrival, with postage on top each way. The rebuild carries a lifetime, unlimited-mileage warranty, with no time limit and no mileage cap.

One detail on the form earns its place: whether the failure followed an oil warning, a missed service or recent engine work. A bearing that wore out on clean oil looks different on the bench from one that ran short of it, and the answer is read against what the strip shows.

BMW N47 Turbo FAQ

Final Thoughts

“N47 turbo” sounds like the name of a part, and it is really the name of an engine that BMW paired with several. The catalogue sorts those turbochargers by output more clearly than by anything else: smaller single units at the lower outputs, the Mitsubishi TF035 through most of the middle, and two turbos together at the top. The badge on the car is shared with two other engines, and even the engine code leaves the reference open.

A rebuild is the one route where none of that has to be solved in advance, because the unit that goes back is the one your engine was already running. Check the power figure, rule out the actuator and the cheaper imitators, and take the turbo off before a worn bearing has time to take the wheels and shaft with it.