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B38 BMW B-series modular platform Petrol 2014-present

B38 engine — BMW 1.5 (1.5L I3 12V DOHC Twin-scroll Turbo VVT (Valvetronic + Double-VANOS))

1.5L I3 12V DOHC Twin-scroll Turbo VVT (Valvetronic + Double-VANOS) · 102-140 hp · 180-220 Nm

The B38 is BMW's 1.5-litre turbocharged three-cylinder from the B-series modular family, with twin-scroll turbo, Valvetronic and double VANOS, in production since 2014 at 102-140 hp. It is fitted to the BMW F40 116i and 118i, the F44, F45 and F46 Active and Gran Tourer, and a wide range of Minis: F56, F55, F57, F54 and F60. Common reasons for a visit are cold-start chain rattle with cam-crank correlation codes, oil consumption from rings and valve stem seals, a rattling wastegate actuator, high-pressure fuel pump follower wear and electric water pump faults. Torque figures on this page cover the cylinder head bolts, crank pulley bolt, main bearing caps, turbocharger-to-manifold nuts and spark plugs.

On cold-start noise, use a stethoscope to tell chain rattle at the front cover from lifter tick at the valve cover, then check for P0016/P0017. With oil use, run a leak-down test before condemning rings. Light-throttle metallic rattle usually means wastegate actuator play. For heat complaints, check the electric water pump's target against actual speed in live data before replacing the thermostat.

Check first

  • Timing chain: inspect at 90,000 km, sooner if there is a cold-start rattle or extended oil intervals.
  • Oil: 5W-30 to BMW LL-04 at 15000 km; non-spec oil accelerates chain wear.
  • Wastegate actuator: play gives a light-throttle rattle; the actuator alone usually fixes it.
  • Electric water pump: compare target and actual speed in live data before replacing parts.
  • After valve cover or camshaft work, complete the Valvetronic adaptation before clearing codes.
  • Head bolts are TTY; renew them whenever the head is disturbed.

Engine overview

Manufacturer
BMW B-series modular platform
Displacement
1.5 L
Configuration
I3 12V DOHC Twin-scroll Turbo VVT (Valvetronic + Double-VANOS)
Power
102-140 hp
Torque
180-220 Nm
Production years
2014-present
Fuel type
Petrol

Vehicles with this engine

BMW F40 116i (2019-) BMW F40 118i (2019-) BMW F44 218i Active Tourer (2021-) BMW F45 216i/218i Active Tourer (2014-2021) BMW F46 216i/218i Gran Tourer (2015-2021) Mini F56 Cooper (2014-) Mini F55 Cooper (2014-) Mini F57 Cooper Convertible (2016-) Mini F54 Cooper Clubman (2015-) Mini F60 Cooper Countryman (2017-)

Known failures & weak points

Timing chain and tensioner wear can appear from around 90,000-130,000 km, especially with extended oil-change intervals or non-spec oil, giving a brief cold-start rattle and P0016/P0017 cam-crank correlation codes. TTY head bolts must be renewed if the cylinder head is disturbed.
Some B38 units show elevated oil consumption from worn piston rings and degraded valve stem seals, seen as blue smoke on cold start and overrun plus fouled spark plugs. Perform a leak-down test before condemning the rings.
The twin-scroll turbo's wastegate actuator can develop play over time, producing a metallic rattle at light throttle; actuator replacement alone usually resolves it without needing a full turbo.
High-pressure fuel pump (HPFP) cam follower wear at 40,000-70,000 km: The mechanical HPFP is driven off the exhaust camshaft lobe; the roller follower and its bore wear, leading to metal contamination of fuel system. Symptoms: hard start, P0087 (fuel rail pressure low), rough running, injector tick. Follower inspection is a 30-min job — mandatory at every timing chain service. Flush entire fuel system if metal debris found.
Coolant loss via plastic thermostat housing and water pump at 70,000-110,000 km: The electric water pump (EWP) impeller debonds from shaft and the integrated plastic thermostat housing cracks at the coolant sensor boss. Symptoms: coolant warning light, overheating, white residue around housing. EWP failure also triggers 5A30 DME fault. bleed system via ISTA bleed routine — manual bleeding is insufficient due to electronic pump control.
Carbon buildup on intake valves at 50,000-80,000 km: Direct injection only (no port injection on base B38) causes heavy carbon deposits on intake valve stems and seats. Symptoms: rough idle, misfires (P030X), reduced power, increased fuel consumption. Walnut blasting is the only effective remedy; Recommend every 60,000 km as preventive maintenance. Catch-can installation on PCV line reduces recurrence interval.
Valvetronic eccentric shaft sensor and motor failure at 80,000-120,000 km: The Valvetronic system's eccentric shaft stepper motor and position sensor fail, causing limp mode (fixed valve lift), P1083/P1085 codes, and poor throttle response. Often preceded by sluggish cold-start response. Always clean eccentric shaft splines and apply Optimoly TA paste on reassembly — dry splines cause repeat failures within 20,000 km.
Crankcase ventilation (PCV) membrane diaphragm failure at 60,000-90,000 km: The integrated PCV valve diaphragm in the valve cover tears, causing excessive crankcase pressure, oil leaks past seals, oil ingestion into intake, and rough idle with P0171 (lean). Always replace breather hoses simultaneously as they harden and crack.

Common torque specifications

Head Bolts Stage 1: 20 Nm; Stage 2: +90°; Stage 3: +90° — TTY bolts, single use only, must be replaced; total 4-stage sequence per BMW SI unconfirmed
Crank Pulley Bolt 410 Nm — use flywheel locking tool 11 9 360; do NOT use impact gun for final torque unconfirmed
Main Bearing Cap Bolts Outer bolts: 15 Nm + 70°; Inner bolts: 30 Nm + 90° — TTY, replace on every removal unconfirmed
Turbocharger To Exhaust Manifold Nuts 20 Nm — use new copper nuts; anti-seize on studs mandatory unconfirmed
Spark Plugs 25 Nm — NGK ILZKBR8B8DG OEM spec; do not exceed, aluminum head strips easily unconfirmed

Figures marked unconfirmed could not be cross-checked against a workshop source. Verify against the vehicle’s own documentation before tightening.

Service intervals

Timing Chain Inspect at 90,000 km; no OEM replacement interval specified but industry best practice replacement at 120,000-150,000 km or at first cold-start rattle
Oil Change Km 15000
Oil Spec 5W-30 BMW Longlife-04 (LL-04) — ACEA C3; do NOT use LL-01 spec oils
Oil Capacity L 4.3
Coolant Spec BMW Coolant / Antifreeze (blue) — silicate-free OAT, pre-mixed 50/50; BMW part 83192211191

Pro tips from the field

Always perform an ISTA/D or ISTA+ oil service reset AND check for pending Valvetronic adaptation faults after any valve cover or camshaft work — the Valvetronic system requires a full adaptation drive cycle (cold start to operating temp) before fault codes stabilize. Clearing codes without adaptation causes phantom misfires and customer comebacks.
When diagnosing cold-start rattle, distinguish timing-chain rattle (fades within a few seconds, heard at the front timing cover) from hydraulic lifter tick (persists longer, higher pitched, heard at the valve cover) using a mechanic's stethoscope.
The B38 electric water pump communicates via LIN bus — a failed pump will NOT always trigger an overtemp warning immediately because the DME models coolant temperature. Always verify actual pump operation with ISTA live data (target vs. actual pump speed) before condemning the thermostat. A pump showing 0 RPM commanded speed during warm-up is a DME/wiring fault, not a pump fault.
Injector coding is required on B38 after any injector replacement — each injector must be programmed via ISTA+ or a compatible tool so the DME applies correct per-injector correction values. Skipping this causes rough idle, misfires, and adaptation drift.

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Who makes these pages, and how

TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.

The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.

Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.

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Workshop data on this page last updated 14 Oct 2026.