BMW B57 engine report, 330d G20
BMW B57 · 330d (G20)
3.0 LDieselInline-62019–2025
78/100
Checked by hand
[good]
Strong six, but the emissions kit needs proof
Worth buying if the service history checks out.
ExcellentGoodSolidRiskyAvoid
- Known issues
- 10
- Critical
- 3
- Sources
- 23
Verdict
A healthy B57 is a genuinely good engine, and the paperwork is how you tell a healthy one.
DPF clogging and regeneration problems are very common, and EGR valves and swirl flaps coking up is a regular complaint, so look for a car with long runs in its history and no warning lights on the dash. Ask directly whether the water pump, thermostat and intercooler have been done, and ask about oil consumption before the seller volunteers it. Injector faults are rare and usually easy to pin down. Ringland and head gasket failures are rare too, but bad enough that a cold start and a compression check are not optional.
Specs
- Displacement
- 3.0 L2,993 cc
- Layout
- Inline-6
- Fuel
- Diesel
- Compression
- 16.0:1 (B57D30C), 16.5:1
- Production
- July 2015 – present
- Chassis
- G20
- Fitted
- 2019–2025
Known issues
10 confirmed · sorted by severity
CriticalEGR cooler leak
The cooler for the recirculated exhaust gas develops an internal leak. Coolant disappears with no visible drip, and the exhaust may smell sweet or smoke white. Left alone, it contaminates the intake and can overheat the engine.
Symptoms
- Coolant Loss
- Warning Light
- Burning Smell
- Smoke (White/Blue/Black)
- Reduced Power Mode
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
Rare · Design weakness. Can destroy the engine if ignored. Not safely drivable.
CriticalHead gasket failure
Head gasket failure, often preceded by overheating; can lead to a warped head or cracked block if not addressed.
Symptoms
- Coolant Loss
- Smoke (White/Blue/Black)
- Warning Light
How often
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 · Design weakness. Does not normally destroy the engine. Still drivable.
Evidence
12 owner reports back this, confidence 50/100.
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
Occasional · Design weakness. Can destroy the engine if ignored. Still drivable.
ModerateWater pump failure
Water pump seal or bearing failure (mechanical or electric pump), causing coolant loss.
Symptoms
- Coolant Loss
- Warning Light
How often
Occasional · Design weakness. 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
Common · Expected maintenance. Does not normally destroy the engine. Still drivable.
LowIntercooler failure or leak
Intercooler core cracking or pipe seal failure, causing boost loss.
Symptoms
- Power Loss
How often
Occasional · Design weakness. Does not normally destroy the engine. Still drivable.
LowThermostat / temperature sensor failure
Thermostat sticking open or closed, or temperature sensor drift, causing incorrect operating temperature.
Symptoms
- Warning Light
How often
Occasional · Design weakness. Can destroy the engine if ignored. Still drivable.
LowFuel injector failure
Injector wear, sticking, or seal failure causing misfires, rough running, or fuel leaks.
Symptoms
- Misfire
- Rough Idle
- Fuel Smell
How often
Rare · Age-related wear. Does not normally destroy the engine. Still drivable.
- Critical
- High
- Moderate
- Low
DPF clogging / regeneration failurefrom 190k 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
- EGR cooler leakHad this? Tell us at what mileage
- DPF clogging / regeneration failureHad this? Tell us at what mileage
- Piston ringland failureHad this? Tell us at what mileage
- Head gasket failureHad this? Tell us at what mileage
- Excessive oil consumptionHad this? Tell us at what mileage
- Water pump failureHad this? Tell us at what mileage
- EGR valve / swirl flap cloggingHad this? Tell us at what mileage
- Intercooler failure or leakHad this? Tell us at what mileage
- Thermostat / temperature sensor failureHad this? Tell us at what mileage
- Fuel injector failureHad this? Tell us at what mileage
Buying checklist
BMW B57 (330d G20) · Buying checklist
Sources
Updated 15 Sept 2026 · scoring v2.7
Behind this report sit 23 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.