BMW M47 engine report
BMW M47 · 320d (E46/E90)
2.0 LDieselInline-42001–2007
82/100
[good]
Tough diesel let down by its emissions kit
Worth buying, but only on the right car.
ExcellentGoodSolidRiskyAvoid
- Known issues
- 6
- Critical
- 1
- Sources
- 57
Verdict
The high-pressure fuel pump is the one to take seriously here: a very common failure and an expensive one.
Look for evidence it has been replaced, and treat rough running or hard starting as a reason to leave. DPF clogging and EGR and swirl flap build-up are common too, and short journeys make both worse, so a car with motorway miles and a clean service record is the safer bet. Transmission failure is less frequent but serious, which is worth a longer test drive watching for jerky or delayed shifts. Glow plugs and the odd wiring fault are common and cheap, and not worth losing a good car over.
Specs
- Displacement
- 2.0 L
- Layout
- Inline-4
- Fuel
- Diesel
- Production
- 1999 – 2007
- Chassis
- E46/E90
- Generation
- Pre-LCI
- Fitted
- 2001–2007
Known issues
6 confirmed · sorted by severity
CriticalSwirl flap failure
Small flaps in the intake ports wear on their spindles until one breaks off and is drawn into the cylinder, wrecking the valves and piston. Many owners have them removed or blanked off as a precaution.
Symptoms
- Sudden Power Loss
- Engine Knock
- Metallic Rattle
- Smoke (White/Blue/Black)
How often
Common · Design weakness. Can destroy the engine if ignored. Not safely drivable.
Evidence
1 owner report backs this, confidence 95/100.
HighHigh-pressure fuel pump failure
HPFP wear or failure, sometimes shedding metal debris into the fuel system.
Symptoms
- Misfire
- Warning Light
- Hesitation
How often
Very common · Age-related wear. Does not normally destroy the engine. Not safely drivable.
Evidence
12 owner reports back this, confidence 40/100.
ModerateDPF clogging / regeneration failure
Diesel particulate filter clogs, especially with short/urban trips that prevent regeneration, triggering warning lights or limp mode.
Symptoms
- Warning Light
- Reduced Power Mode
How often
Common · Environmental. Does not normally destroy the engine. Still drivable.
Evidence
8 owner reports back this, confidence 50/100.
LowECU fault or wiring issue
ECU hardware fault or injector wiring loom degradation causing misfires or no-start conditions.
Symptoms
- Warning Light
- Misfire
How often
Common · Manufacturing defect. Does not normally destroy the engine. Still drivable.
Evidence
7 owner reports back this, confidence 50/100.
LowGlow plug failure
Glow plug wear or failure causing hard cold starts on diesel engines.
Symptoms
- Warning Light
How often
Common · Age-related wear. Can destroy the engine if ignored. Still drivable.
Evidence
8 owner reports back this, confidence 45/100.
LowEGR valve / swirl flap clogging
EGR valve, EGR cooler, or intake swirl flaps clog with carbon/soot, causing rough running or limp mode.
Symptoms
- Rough Idle
- Reduced Power Mode
- Warning Light
How often
Occasional · Expected maintenance. Does not normally destroy the engine. Still drivable.
Evidence
5 owner reports back this, confidence 45/100.
- Critical
- High
- Moderate
- Low
Swirl flap failurefrom 140k km
High-pressure fuel pump failurefrom 80k km
DPF clogging / regeneration failurefrom 161k km
ECU fault or wiring issuefrom 233k km
Glow plug failurefrom 137k km
EGR valve / swirl flap cloggingfrom 355k km
Buying checklist
0 of 5 checked
Sources
Updated 11 Sept 2026 · scoring v2.7
This report combines 57 owner posts, forum threads and official records. An issue only makes the list once the evidence is strong enough, an official recall on its own or several independent owner reports, and the score weighs how often each problem happens against how bad it is when it does.