BMW B47 engine report
BMW B47 · 1 Series (F20)
2.0 LDieselInline-42015–2019
70/100
[good]
Safe diesel if the chain was looked after
Worth buying if the service history checks out.
ExcellentGoodSolidRiskyAvoid
- Known issues
- 8
- Critical
- 2
- Sources
- 69
Verdict
Check the timing chain history before anything else.
Stretch and worn guides are the fault this engine is known for, and the EGR valve and swirl flaps coke up alongside it. The DPF is the usual diesel story: very common trouble on a car that only ever did short trips, so look for warning lights or recent regeneration work on the invoices. Ringland failure and heavy oil use do get reported, rarely enough that they should not drive the decision. Sensor and ECU faults are ordinary used-car noise.
Specs
- Displacement
- 2.0 L1,995 cc
- Layout
- Inline-4
- Fuel
- Diesel
- Compression
- 16.5:1
- Production
- 2014–present
- Chassis
- F20
- Generation
- LCI
- Fitted
- 2015–2019
Known issues
8 confirmed · sorted by severity
CriticalEGR cooler leak (fire risk)
The EGR cooler cracks internally and leaks coolant into the exhaust-gas path. Glycol deposits build up in the intake manifold and can ignite. BMW recalled many of its diesels for this in 2018, so check whether the recall work has been done.
Symptoms
- Coolant Loss
- Warning Light
- Burning Smell
- Smoke (White/Blue/Black)
How often
Common · Manufacturing defect. Can destroy the engine if ignored. Not safely drivable.
Evidence
3 owner reports back this, confidence 95/100.
CriticalPiston ringland failure
Piston ringland cracking under high cylinder pressure/heat, common on tuned forced-induction engines.
Symptoms
- Power Loss
- Smoke (White/Blue/Black)
- Misfire
How often
Very rare · Design weakness. Does not normally destroy the engine. Not safely drivable.
Evidence
1 owner report backs 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
Very common · Environmental. Does not normally destroy the engine. Still drivable.
Evidence
19 owner reports back this, confidence 45/100.
ModerateTiming chain stretch / guide wear
Timing chain elongates or plastic guides wear prematurely, causing rattle, incorrect valve timing, or in severe cases chain failure.
Symptoms
- Knocking Noise
- Cold Start Rattle
- Warning Light
How often
Common · Age-related wear. Does not normally destroy the engine. Still drivable.
Evidence
11 owner reports back this, confidence 40/100.
ModerateExcessive oil consumption
Worn valve stem seals, piston rings, or a clogged PCV/oil separator system causing oil consumption above manufacturer spec.
Symptoms
- Oil Consumption
- Smoke (White/Blue/Black)
How often
Very rare · Age-related wear. Does not normally destroy the engine. Still drivable.
Evidence
1 owner report backs this, confidence 40/100.
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
Very common · Expected maintenance. Can destroy the engine if ignored. Still drivable.
Evidence
21 owner reports back this, confidence 40/100.
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
Occasional · Manufacturing defect. Does not normally destroy the engine. Still drivable.
Evidence
5 owner reports back this, confidence 40/100.
LowEngine sensor failure
Crankshaft, camshaft, MAP, lambda/O2, or MAF sensor failure causing rough running, stalling, or incorrect fueling.
Symptoms
- Warning Light
- Rough Idle
- Misfire
How often
Occasional · Age-related wear. Does not normally destroy the engine. Still drivable.
Evidence
6 owner reports back this, confidence 40/100.
- Critical
- High
- Moderate
- Low
EGR cooler leak (fire risk)from 60k km
DPF clogging / regeneration failurefrom 152k km
Timing chain stretch / guide wearfrom 88k km
EGR valve / swirl flap cloggingfrom 100k km
Piston ringland failurefrom 200k km
ECU fault or wiring issuefrom 148k km
Engine sensor failurefrom 250k km
Excessive oil consumptionfrom 200k km
Buying checklist
0 of 7 checked
Sources
Updated 16 Sept 2026 · scoring v2.7
This report combines 69 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.