BMW B47 engine report, 118d F20 LCI
BMW B47 · 1 Series (F20)
2.0 LDieselInline-42015–2019
70/100
Checked by hand
[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.
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.
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.
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.
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.
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.
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
DPF clogging / regeneration failurefrom 152k km
Timing chain stretch / guide wearfrom 88k km
EGR valve / swirl flap cloggingfrom 100k km
Check the car you're looking at
Set the mileage of the car you're looking at. Problems owners say start before it are the ones to ask the seller about; the next ones are what to budget for.
km
2 already past · 0 coming up
Already past: ask for proof
Owners say these start before this mileage. Nothing tells us whether this car had them fixed, so ask, and ask for the invoice.
The next 30k km
Nothing owners report starts in this stretch.
Further on DPF clogging / regeneration failure
No reliable mileage EGR cooler leak (fire risk), Piston ringland failure, ECU fault or wiring issue, Engine sensor failure, Excessive oil consumption
Too few owners said at what mileage these start, so they are not placed above.
Buying checklist
BMW B47 (118d F20 LCI) · Buying checklist
Sources
Updated 16 Sept 2026 · scoring v2.7
Behind this report sit 69 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.