BMW M47 engine report, 320d E46
BMW M47 · 320d (E46/E90)
2.0 LDieselInline-42001–2007
80/100
Checked by hand
[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.
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.
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.
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.
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.
- Critical
- High
- Moderate
- Low
DPF clogging / regeneration failurefrom 161k km
Check the car you're looking at
Owners rarely say at what mileage this engine's problems start, so they aren't sorted by mileage here. These are the ones to ask the seller about, the ones it's best known for first.
What to ask about
- Swirl flap failureHad this? Tell us at what mileage
- High-pressure fuel pump failureHad this? Tell us at what mileage
- DPF clogging / regeneration failureHad this? Tell us at what mileage
- ECU fault or wiring issueHad this? Tell us at what mileage
- Glow plug failureHad this? Tell us at what mileage
- EGR valve / swirl flap cloggingHad this? Tell us at what mileage
Buying checklist
BMW M47 (320d E46) · Buying checklist
Sources
Updated 11 Sept 2026 · scoring v2.7
Behind this report sit 57 owner posts, forum threads and official records. Nothing gets on the list on one person's word. It takes a recall, or owners on separate platforms describing the same fault. The score then sets how often a problem turns up against the damage it does.