BMW Buyer's Guide

Comprehensive Used Car Analysis
← Back to F20 / F21
B38B15 1.5L 3-Cylinder Petrol
B38B15 1.5L 3-Cylinder Petrol
1 / 2

B38B15

1.5L 3-Cylinder Petrol
B-series • B38 family • 2014–2025
76%
Engine Reliability
The B38 is BMW's modular 3-cylinder turbo petrol engine, sharing its design DNA with the B48 (4-cyl) and B58 (6-cyl). Impressively smooth for a 3-cylinder with a balance shaft. Generally reliable with minor coolant concerns.
1.5L
Displacement
I3
Layout
109–136 hp
Power
180–220 Nm
Torque
Petrol
Fuel
Turbocharged
Aspiration
Technology & Features
Modular engine architectureTwinPower TurboValvetronic IVDouble-VANOSDirect injection
Fuel SystemDirect injection
ValvetrainDOHC 12-valve, Valvetronic, Double-VANOS
Used In 2 Applications
1 Series F20 / F21 116i, 118i 1 Series F40 118i
1
Known Issues
0
Critical
1
Wear Items
2
Applications

Known Issues – B38B15

medium Coolant Loss Moderate (~20%)
Minor coolant leaks from thermostat housing or water pump area.
Typical Mileage
60,000–100,000 km
Est. Repair Cost
€200–€500
DIY Friendly
✓ Yes
Low coolant warningSweet smell from engine bay

Wear & Maintenance – B38B15

Spark Plugs Every 60,000 km
NewReplace
Replacement Cost€60–€100
Wear Factor55%

Applications (2)

1 Series F20 / F21

F20
2011–2019
Variants116i, 118i
Power109–136 hp
Torque180–220 Nm
BodyHatchback
Reliability74%
Car-Specific Issues (F20)
mediumTailgate Wiring Harness Failure
lowDriveshaft Vibration

1 Series F40

F40
2019–2025
Variants118i
Power140 hp
Torque220 Nm
BodyHatchback, Sedan
Reliability80%
📝 The 7-speed DCT can exhibit low-speed judder in stop-start traffic.
Car-Specific Issues (F40)
lowFront-Wheel-Drive Torque Steer (M135i)

Transmissions (3)

6-Speed Manual (Getrag)
6-Speed Manual (Getrag)
6-Speed Manual (Getrag)
1 / 3

6-Speed Manual (Getrag)

Getrag • 6-speed manual • 2003–2019

Getrag 6-speed manual used across a wide range of BMWs. Different models handle various torque capacities. Known for precise, mechanical shift action. The GS6-53DZ handles up to 500Nm (used with 335i/M135i).
Known Issues2
medium 2nd Gear Synchro Wear Moderate (~20%)
Second gear synchros can wear, especially on higher-torque applications, causing grinding on fast 2nd gear shifts.
Typical Mileage
100,000–180,000 km
Est. Repair Cost
€800–€1,500
DIY Friendly
✗ Specialist
Grinding into 2nd gearDifficulty downshifting to 2nd
low Clutch Release Bearing Noise Moderate (~25%)
Clutch release (throw-out) bearing develops a chirp or whine when clutch is depressed.
Typical Mileage
80,000–150,000 km
Est. Repair Cost
€400–€800 (usually replaced with clutch)
DIY Friendly
✗ Specialist
Chirping with clutch pressedWhining noiseVibration in pedal
Wear Items
Clutch Assembly 100,000–180,000 km
NewReplace
Replacement Cost€700–€1,500
Wear Factor55%
Dual Mass Flywheel 150,000–250,000 km
NewReplace
Replacement Cost€500–€1,000
Wear Factor45%
Transmission Fluid Every 80,000 km
NewReplace
Replacement Cost€50–€120
Wear Factor30%
Fluid TypeMTF-LT-4 / MTF-LT-5
Service IntervalLifetime fill (recommended every 80,000 km)
8-Speed Automatic (ZF 8HP)
8-Speed Automatic (ZF 8HP)
8-Speed Automatic (ZF 8HP)
1 / 3

8-Speed Automatic (ZF 8HP)

ZF • 8-speed automatic • 2009–present

Widely considered one of the best automatic transmissions ever made. Lightning-fast shifts, excellent efficiency, and remarkable reliability. Used across BMW's entire range from 1 Series to 7 Series. Even better with regular fluid services. The 8HP70/75 handles V8 and V12 torque.
Known Issues1
medium Mechatronic Sleeve Leak (Early Production) Occasional (~10%)
Early production 8HP units can develop a transmission fluid leak from the mechatronic sleeve connector.
Typical Mileage
80,000–150,000 km
Est. Repair Cost
€200–€500
DIY Friendly
✗ Specialist
Fluid leakLow fluid warningShifting hesitation
Wear Items
Transmission Fluid & Filter Every 80,000–100,000 km
NewReplace
Replacement Cost€300–€600
Wear Factor40%
Fluid TypeZF Lifeguard 8
Service IntervalEvery 80,000–100,000 km
7-Speed DCT (DKG/M-DCT)
7-Speed DCT (DKG/M-DCT)
1 / 2

7-Speed DCT (DKG/M-DCT)

Getrag • 7-speed dct • 2008–present

BMW's dual-clutch transmission, used in performance models and the F40 1 Series. Offers lightning-fast shifts for sporty driving but can judder at low speeds. The wet-clutch design handles high torque but requires regular fluid changes. The M-DCT variant was used in M3/M4.
Known Issues2
medium Low-Speed Judder Common (~30%)
Characteristic DCT judder during low-speed maneuvers, parking, and stop-start traffic. Can sometimes be improved with a software update.
Typical Mileage
20,000–60,000 km
Est. Repair Cost
€0 (software update) – €1,500 (clutch pack)
DIY Friendly
✗ Specialist
Shuddering at low speedHesitant take-offClunking in reverse
high Clutch Pack Wear Moderate (~20%)
Clutch packs wear, especially in urban driving with frequent stop-start. More aggressive driving actually helps keep clutches clean.
Typical Mileage
80,000–150,000 km
Est. Repair Cost
€1,500–€3,000
DIY Friendly
✗ Specialist
SlippingShuddering on accelerationLoss of drive
Wear Items
DCT Fluid Change Every 60,000 km
NewReplace
Replacement Cost€200–€400
Wear Factor50%
Clutch Pack 80,000–150,000 km
NewReplace
Replacement Cost€1,500–€3,000
Wear Factor45%
Fluid TypePentosin FFL-4 / Castrol BOT 130 M
Service IntervalEvery 60,000 km