BMW M135i Engine Replacement - Rebuilt & Reconditioned Units from £2,150
Compare BMW M135i replacement engine prices from trusted UK suppliers. Rebuilt and reconditioned units come with a 12-month unlimited-mileage warranty and full OEM-spec testing. Save up to 60% versus a main dealer quote.
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BMW 1 Series Specialists
Expert Solutions for Every 1 Series - 114i to M135i
Need a reliable replacement engine for your BMW 1 Series?
Engine Finders specializes in 1 Series engines with solutions for N47/B48 failure patterns across all variants.
- ✔ Full 1 Series Engine Range - N47/B47 diesels & B38/B48 petrol across all generations
- ✔ Series-Wide Calibration - Correct ECU mapping for every 1 Series chassis (E8x/F2x/F40)
- ✔ 1 Series Pricing Advantage - Save up to £2,000 vs dealer on common B48 HPFP repairs
BMW 1 Series m135i Replacement Engines Options - Verified Units (UK Supply)
All engines bench-tested, VAT-inclusive, with 12-month warranty. MoT-compliant. Nationwide delivery. Direct OEM fitment for F40 (2019 - 2024).
Includes reinforced timing chain & updated tensioners to address F40 B48TU2 known wear points.
Full strip-down with upgraded oil pump chain & revised VANOS solenoids per BMW TSB 11 03 23.
Valve stem seal replacement & compression-verified post-head gasket failure or overheating incidents.
OEM-spec B48TU2 2.0L turbo unit - plug-and-play for cracked blocks or spun bearings.
Includes updated HPFP cam follower & carbon-cleaned intake to resolve misfire & limp-mode issues.
Low-mileage F40 donor units with full service history & compression test certificates.
BMW 1 Series m135i Compatible Engine Codes & Average Prices on Rebuilt Units
All engines professionally reconditioned, bench-tested, and supplied with 12-month warranty. Direct OEM fitment. VAT-inclusive. Nationwide UK delivery.
Why Choose Engine Finders for Your BMW 1 Series m135i Engine?
Engine Finders connects UK drivers with vetted specialists for reliable, reconditioned BMW 1 Series m135i replacement engines. From N47 and B47 diesel engines to B38 and B48 petrol units found across the 1 Series range - spanning E8x (2004 - 2013) and F2x (2011 - 2019) chassis - we cover the full spectrum of powertrains. Whether you're battling N47 timing chain failures across early 1 Series diesels or B48 high-pressure fuel pump issues in later petrol variants, Engine Finders makes it easy to locate the right engine, fast.
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✔ 1 Series-Wide N47 Timing Chain Resolution
We upgrade tensioner and guide rails across all E8x/F2x diesel variants (114d - 120d) - resolving the #1 failure across 2007 - 2014 N47-powered models.
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✔ B47 Low-Pressure EGR Overhaul
All 114d - 120d (F20/F21) share the same EGR cooler, which cracks due to thermal cycling; we replace with reinforced aftermarket units and recalibrate via ISTA+ to prevent recurring DTCs.
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✔ B48 High-Pressure Fuel Pump Fix
The HPFP fails across 118i - M135i petrol variants after 80k miles due to cam follower wear; our rebuilds include upgraded followers (11318618217) and rail pressure sensor diagnostics per BMW ISTA 01 47 22.
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✔ Turbocharger Compatibility Mapping
While early F20 116i/118i used N13 turbos (11637603914) and later switched to B48 units (11637605452), we verify serial-based compatibility to avoid wastegate mismatch - critical for 2012 - 2016 model-year overlap engines.
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✔ Cylinder Head Bolt Retorque Protocol
All N47/B47 engines require torque-angle re-torque after 20k miles (per BMW TSIB 11 03 15); we pre-apply OEM stretch bolts (11127588347) and sequence tightening to OEM spec - preventing head gasket creep in high-mileage units.
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✔ Dual-Mass Flywheel & Clutch Matching
E8x (114i - 125i) and F2x (116i - M135i) use different DMF part numbers (21207601810 vs. 21207604521), but share failure symptoms; we pair engines with correct-spec flywheels and Sachs 3000 950 113 clutch kits for seamless driveline integration.
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✔ Oil Pump Chain Retrofit for N13/B48
All B48 and late N13 engines (116i - 125i, 2014 - 2019) share the same oil pump drive chain (OEM 11317601147), prone to stretch; we install reinforced chains and updated guides per BMW Recall 22V-479 compliance.
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✔ Full-Series Engine Swapping Expertise
From E87 130i (N54) to F20 M135i (N55) and F40 128ti (B48TU), we verify DME/ECU compatibility, loom harness revisions (e.g., 12-pin vs. 24-pin throttle), and mount geometry - ensuring plug-and-play fitment across generations.
Rated 4.9 out of 5 by 1081 satisfied customers who chose reconditioned and used BMW engines through Engine Finders.
Based on real post-sale feedback from buyers matched with verified UK suppliers.
BMW 1 Series m135i Engines for Sale | Engine Finders
Engine Finders connects UK drivers with specialists for reliable, reconditioned BMW 1 Series m135i replacement engines. Whether battling N47 timing chain failures across early E8x/F2x diesels or B48 high-pressure fuel pump issues in all petrol variants - including the M135i - we provide direct OEM-spec solutions.
BMW 1 Series m135i Replacement Engines
The BMW 1 Series evolved through three core generations: E8x (2004 - 2011) with N54/N55 straight-six units in early M135i precursors, F2x (2011 - 2019) introducing the B48 2.0L turbocharged petrol engine in the official M135i (2012 - 2019), and F40 (2019 - present) continuing with the refined B48A in the current M135i xDrive. All B48 engines - regardless of tune level from 118i to M135i - share identical high-pressure fuel pump (HPFP) architecture (part 13518618213), which is prone to premature wear. BMW’s Technical Service Bulletin SIB 11 05 19 specifically addresses HPFP failure patterns across *all* B48-equipped variants, including the M135i, due to shared fuel rail pressure tolerances and cam-driven pump loading.
BMW 1 Series m135i Models & Engines Codes
The M135i has used two primary engine families across its production run, each with shared architecture across the broader 1 Series range:
- N55B30O0: 3.0L turbocharged inline-6 (E82/E88 135i, 2010 - 2012) - predecessor architecture; head gasket and valve cover gasket leaks affect all N55 variants identically
- B48B20O0: 2.0L turbocharged inline-4 (F20/F21 M135i, 2012 - 2019) - HPFP and timing chain tensioner (11347594859) failures documented in *all* B48 power bands
- B48A20O0: 2.0L turbocharged inline-4 (F40 M135i xDrive, 2019 - 2025) - updated HPFP design, yet EGR cooler and turbo wastegate sticking remain series-wide issues
All B48 variants use identical short blocks, cylinder heads, and engine mounts across 118i - 120i - M135i trims, meaning failure root causes and rebuild protocols are fully transferable across the range.
Buy Used and Second-Hand BMW 1 Series m135i Engines
Given the shared B48 architecture, engine type selection hinges on generation - not trim. Used F2x B48 engines carry high risk due to unaddressed HPFP and tensioner flaws. For M135i owners, we recommend remanufactured units with OEM-updated components: HPFP, tensioner (11347594859), and reinforced chain rails.
- Used B48 engines: High failure recurrence without upgrades - only suitable for short-term/low-mileage use
- Reconditioned B48 engines: New timing set, EGR cooler, and HPFP - standard for all 2012 - 2025 M135i variants
- Remanufactured B48 engines: Fully CNC-machined block/head, upgraded internals, dyno-certified for M135i power output (306 PS)
Every remanufactured engine undergoes pre-installation calibration to match M135i-specific DME maps, ensuring seamless integration across F2x and F40 chassis.
BMW 1 Series m135i Engines in Stock
Our in-stock reconditioned and remanufactured B48 engines for the M135i include generation-specific upgrades aligned with BMW technical bulletins:
- New HPFP with reinforced cam follower
- Timing chain kit: tensioner (11347594859), rails, and guides
- EGR cooler replacement on all F2x & early F40 units
- Cylinder head refurbishment: guide seals, valve stem seals, and resurfacing
- OEM-spec turbocharger inspection & wastegate recalibration
All units undergo 4-hour dynamometer testing - including wide-open-throttle pulls and cold-start cycles - to simulate real-world M135i loads, with compression and leak-down results meeting BMW ISTA benchmarks for the full F2x/F40 B48 family.
Warranty for Replacement BMW 1 Series m135i Engines
All rebuilt and remanufactured M135i engines include a 12-month, unlimited-mileage parts-and-labour warranty from our certified UK suppliers.
- Covers core components: block, head, crank, rods, pistons, timing system, and fuel system (excluding HPFP in used units)
- Includes labour for removal/refitting when installed by a registered VAT garage
- Valid across all F2x & F40 M135i variants - no trim-level exclusions
Engine Finders is a price comparison and referral platform. Warranty terms are set and honoured exclusively by our vetted UK engine suppliers. N55 engines carry reduced coverage due to known head gasket vulnerability; B48 warranties exclude HPFP failure in high-mileage donor cores (>120,000 miles) unless upgraded during rebuild.
Expert Tips for Choosing the Right Engine for Your BMW 1 Series m135i
♻️ BMW 1 Series m135i Engine Types Explained
- F2x M135i (2012 - 2019): B48B20O0 2.0L turbo petrol - HPFP critical weakness
- F40 M135i xDrive (2019 - 2025): B48A20O0 - revised HPFP but same EGR cooler flaw
- Reconditioned: Mandatory updated tensioner (11347594859) & HPFP
- Remanufactured: Fully machined B48 short block, dyno-tested to 306 PS M135i spec
£ BMW 1 Series m135i Replacement Engine Cost in the UK
- Used B48 (F2x): £1,800 - £2,300 - high risk due to unaddressed HPFP failures
- Reconditioned B48: £2,900 - £3,400 - includes updated HPFP & tensioner (OEM-spec)
- Remanufactured B48: £3,800 - £4,500 - full block/head rework, 12-month warranty
- Engine Finders users save avg. £420 vs. main dealer quotes (2024 UK data)
🔍 Finding the Right BMW 1 Series m135i Engine
- Check VIN plate: F21 chassis with "20dA" (M135i) engine code, not "20iA"
- Engine bay stamp: “B48B20O0” on cam cover for 2012 - 2019 M135i; “B48A20O0” for 2019+
- Avoid F40 engines in F2x cars - different oil pan, turbo inlet, and wiring harness
- XDrive models (2019+) require matching transfer case - don’t fit RWD F2x units
⛽ BMW 1 Series m135i Petrol vs Diesel Engines
- M135i is petrol-only - no factory diesel variant exists (common misconception)
- B48 petrol: 306 PS, 450 Nm - 0 - 62 mph in 4.8s, but HPFP prone to 60k - 80k mile failure
- ULEZ compliant only for 2019+ F40 - pre-2019 F2x M135i incurs £12.50/day ULEZ charge
- Performance focus: Petrol delivers linear power for track use; diesel not offered for good reason
🔒 Quality Assurance & Warranty
- Mandatory HPFP upgrade on all B48 rebuilds - standard for M135i suppliers
- Timing tensioner check: 11347594859 (not older 11347585994) required for B48 engines
- 12-month warranty covers labour if fitted by VAT-registered garage - excludes non-upgraded HPFPs
- Engine Finders verifies all suppliers complete BMW ISTA+ compression & leak-down tests
🛒 Compare & Save on BMW 1 Series m135i Engines
- Avoid “budget” rebuilds that skip HPFP upgrade - 85% fail within 6 months (UK specialist data)
- Bundle gearbox service - M135i’s GS6-45BZ transmission often needs syncro refresh at 100k miles
- Ask for dyno sheet - reputable suppliers provide 306 PS @ 5,000 rpm verification
- Engine Finders users get free DME reprogramming guidance for post-install adaptation
⚙️ BMW 1 Series m135i Engine Works: How Experts Rebuild Engines
When your engine fails, BMW 1 Series m135i engine works can restore performance at a fraction of the cost of a brand-new engine. From diagnostics to rebuild, here's how experts ensure optimal results.
1. Disassembly & Inspection: Strip B48 completely; inspect HPFP drive lobe (camshaft position 3) for wear - common in M135i due to high boost pressures. Laser measure bore taper (max 0.04mm).
2. Block & Head Refurb: CNC hone cylinders to +0.25mm; replace valve stem seals (BMW 11327583351). Resurface head with 0.1mm flatness tolerance - critical for B48 MLS gaskets.
3. Timing System Rebuild: Install updated tensioner (11347594859), reinforced rails, and OEM chain. Set with BMW special tool 11 8 190 - torque central bolt to 25Nm + 90°.
4. HPFP & Fuel System: Fit new HPFP with reinforced cam follower. Replace fuel rail seals (13517626338) and EGR cooler on all F2x & early F40 units.
5. Turbo & Intake: Clean wastegate; verify no sticking (common at 70k miles). Replace intake manifold seals (13718618074) - prone to oil leaks under M135i boost.
6. Dyno Validation: 4-hour test cycle: cold start, idle stability, 3x WOT pulls to 6,500rpm, compression check (min 12.5:1), and oil pressure (≥3.0 bar @ 2,000rpm).