BMW M47 (M47D20 / M47TU / M47TU2 / M47R)Injectors
Blocked and seized injectors on the BMW M47
Why this rating?
Medium severity: It can leave you stranded or get worse if ignored, without destroying the engine.
Frequency common: A Spanish BMW specialist workshop and a German used-car buying guide independently cite injector carbonisation as a known weak point of the M47, along with the high-pressure pump on units built before the first facelift; both sources describe it as a recurring problem rather than isolated cases, although we have not found an official campaign or figure for the number of cars affected.[1][2]
Symptoms
- Black smoke when accelerating when one or more injectors stop spraying fuel accurately.[2]Black smoke: other faults that cause it · Garage soon
- Rough running or jerking on gentle acceleration, especially when cold.[1]Jerking: other faults that cause it · Garage soon
- Harder starting than normal if carbon affects the injector seats.[1]Hard to start: other faults that cause it · Garage soon
- Loss of power and a less progressive throttle response.[1]Less power: other faults that cause it · Monitor
Why it happens
Carbon typical of diesel is deposited around the injector seats over the miles, eventually seizing them if nothing is done in time.[1]
On common rail units built before the M47's first facelift, the high-pressure pump that feeds the system is, according to a German used-car guide, relatively prone to failure, which can end up affecting the injectors' operation too.[2]
If it is not repaired: A seized injector worsens combustion and fuel consumption; if ignored for a long time, carbon can end up damaging the injector seat in the cylinder head, making the repair more expensive.[1]
Affected cars and years
The carbonisation problem is documented for the common rail versions (M47D20TU and M47D20TU2); the German source consulted also singles out a high-pressure pump that is "relatively prone to failure" on pre-facelift models. The initial 1998-2001 version, without common rail, uses a different injection system (rotary pump) not covered by these sources, and we have not found specific data on the M47R's injectors.[1][2]
| Version | Years | Codes |
|---|---|---|
| M47D20TU 116-150 hp (2001-2004) | 2001–2004 | M47D20TUM47TUD20 |
| M47D20TU2 122-163 hp (2004-2007) | 2004–2007 | M47D20TU2M47TU2D20 |
Models fitted with the affected versions
BMW
- BMW Serie 1 E872004–2007
- BMW Serie 3 E902005–2007
- BMW Serie 5 E602003–2007
- BMW X3 E832003–2007
- BMW Serie 3 E461998–2005
How much it costs to repair
Includes: Diagnosis, cleaning or replacement of the affected injectors, or of the high-pressure pump if it is the source of the fault.[1][2]
We have not found a published quote in Spain specific to the M47's injectors or high-pressure pump.
Prices in Spain, including VAT. A workshop hour costs on average €38–66 at independent garages and €77–134 at dealerships in Spain, depending on the region and the brand. How we calculate costs
How to check for it before buying a used car
Parts needed
The part or kit that fixes this fault, according to the sources.
Diesel injector (single unit or full kit)[1]
Cleaned or replaced when carbon seizes it or when it loses its seal.
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How to prevent it
Recalls, campaigns and claims
As of 27 September 2026, we have no record of recalls, campaigns or extended manufacturer warranties for this fault. Check with an official dealer using the chassis (VIN) number: they will tell you whether the car has any outstanding campaign.
What owners say
Frequently asked questions
Why do the BMW M47's injectors seize?
Because the carbon typical of diesel fuel gradually deposits around their seats over the miles; a German guide adds that the high-pressure pump on the first common rail units is also relatively prone to failure.[1][2]
Is it expensive to repair the M47's injectors?
We have not found a published quote in Spain; the specialist workshop consulted points out that acting early costs less than waiting for carbon to damage the injector seat in the cylinder head.[1]
Do fuel additives help?
According to the sources consulted, using them preventively helps limit carbon build-up on the injectors, although they are no substitute for cleaning or replacement once the injectors are already seized.[2]
What can you do now?
We will put you in touch with a partner only if you authorise it in the form.
Other BMW M47 faults
- Critical severityFrequency: Very frequentIntakeIntake swirl flap breakage (swirl flaps)Yes: the common rail versions of the M47 (built since 2001) have flaps in the intake manifold that, with diesel soot and heat cycles, can break and be sucked into the cylinder, with a risk of serious damage to the piston, cylinder head and valves.
- High severityFrequency: CommonTurboLoss of power and turbo faultsThe M47's turbo does not usually fail suddenly, but it loses power gradually as carbon builds up in the variable geometry; the 150 hp variant built between September 2001 and November 2003 also accounts for turbo faults documented by specialist workshops.
- Medium severityFrequency: CommonClutchDual-mass flywheel wear (manual gearbox versions)On BMWs with the M47 engine and a manual gearbox, the dual-mass flywheel can wear with mileage, especially with a lot of urban use or long spells in high gears at low revs; typical symptoms are vibrations, a metallic rattle at idle and jerking when pulling away.Appears at around 150,000 km
- Critical severityFrequency: RareOtherOil leak from the brake vacuum pumpA BMW specialist workshop documents that the seals of the M47's vacuum pump, which generates the vacuum needed for brake assistance because a diesel does not produce it naturally, can wear and let oil through, which can end up stiffening the brake pedal.
- Low severityFrequency: OccasionalIntakeFaulty air flow meter on the BMW M47 (loss of power)On the 2.0 M47 diesel the air flow meter appears among parts that can fail with age and cause loss of power or judder. It is fixed by replacing the sensor; other causes must be ruled out first.Repair (garage): €100–€300
More faults with the injectors on other engines and cars
- High severityFrequency: Very frequentOM651Delphi piezo injector failure (220/250 CDI)Yes: 220 and 250 CDI models built between 2008 and 2011 had Delphi piezo injectors that were prone to failing and seizing in the cylinder head. Mercedes-Benz replaced them under warranty in 2009 and switched the 220 CDI to solenoid injectors from 2010-2011, but the 250 CDI kept them.Repair (garage): €3,600–€5,900
- High severityFrequency: CommonBMW N52 / N53N53 piezoelectric injector failureThe N53's piezoelectric direct injectors fail frequently and cause misfires, rough idle and limp mode; replacing them is expensive and they must be coded.
- High severityFrequency: CommonMZR-CDOil dilution from leaking injector seals and DPF regenerationsOn the 2.0 and 2.2 MZR-CD, injector seals that age badly and incomplete particulate filter regenerations on short journeys can let unburnt diesel into the sump, diluting the oil and leaving the engine with less lubrication.
- High severityFrequency: CommonOM642Wear and failure of the Bosch piezo injectorsThe OM642's Bosch piezo injectors can fail from around 150,000-200,000 km, especially with poor-quality diesel; they cannot be repaired, only replaced. Because it is a V engine, those on the rear bank are harder to reach, which pushes up labour costs.Repair: €4,500–€6,500
- High severityFrequency: Common2.2 CDI (OM646)Injector seal leak with carbonisation around the seatYes: the copper washer that seals each injector can harden and let combustion gases through, forming a black crust of carbon around it. It is a known fault on Mercedes CDI diesels of this era, with injectors described as fragile on both the OM611 and the OM646.
- High severityFrequency: Common2.2/2.5 dCiInjection pump or injector failureThe 2.2 dCi's common rail injectors fail fairly often on the X-Trail and Almera, with cases of seizing and leaks; on the Almera with the older YD22DDT, the documented fault is in the injection pump electronics, not the injectors.
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Sources
Every fact on this page links to its source. If you find an error, let us know.
- Motor BMW M47: problemas y averíasDasercars · Technical documentation · consulted 27 September 2026 · in Spanish
- BMW 3er E46: typische Probleme und SchwachstellenGebrauchtwagenberater · Technical documentation · consulted 27 September 2026 · in German