BMW 1 Series 120d Engine ReplacementCompare Prices & Get Quotes
Get quotes today from trusted UK BMW 1 Series 120d engine specialists. Compare prices on reconditioned, rebuilt and used engines for your BMW 120d - covering the 2.0-litre M47, N47 and B47 diesel engines across the E8x, F20/F21 and F40 generations, from 2004 to the present day.
Supply & Fit Available
12-Month Warranty
Nationwide Delivery
100+ Suppliers
From £1,295 to £3,200
Used from £1,295 · Reconditioned from £1,295 · Common codes: M47D20, N47D20A, N47D20O0, N47D20O1, B47D20O0
From £1,295
Tested, bare/short engine
From £1,295
Rod bearings addressed, tested
From quote
Upgraded bearings, full teardown, revised valvetrain
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3 Simple Steps3 Simple Stepsto Finding the Best BMW 1 Series 120d Replacement Engineto Finding the Best BMW 1 Series 120d Replacement Engine
Most replacements completed within 3-5 days.
Variant HistoryBMW 1 Series 120d - Engine History & Specs at a Glance
The BMW 120d has been the performance-oriented diesel model across three generations of the 1 Series in the UK. Launched with the first-generation E87 in 2004, it has evolved through the M47, N47 and B47 engine families - always using a 2.0-litre four-cylinder turbo diesel that delivers strong torque and excellent real-world performance. The 120d badge represents the diesel sweet spot in the 1 Series range, offering near-hot-hatch performance with outstanding fuel efficiency.
Variant HistoryBMW 1 Series 120d - Engine History & Specs at a Glance
The BMW 120d has been the performance-oriented diesel model across three generations of the 1 Series in the UK. Launched with the first-generation E87 in 2004, it has evolved through the M47, N47 and B47 engine families - always using a 2.0-litre four-cylinder turbo diesel that delivers strong torque and excellent real-world performance. The 120d badge represents the diesel sweet spot in the 1 Series range, offering near-hot-hatch performance with outstanding fuel efficiency.
BMW 1 Series 120d
Fuel TypeDiesel
Engine Size Range2.0L (1,995 cc) across all production
Power Output Range163-190 hp across the variant's historyEngine History Timeline
M47D20 2.0L turbo diesel, 163 hp, launched with the E87 five-door and E81 three-door 1 Series
N47D20A 2.0L turbo diesel, 177 hp, introduced with the E87/E81 LCI update
N47D20O0 / N47D20O1 2.0L turbo diesel, 177-184 hp, carried over into the second-generation F20/F21 1 Series
B47D20O0 2.0L turbo diesel (Euro 6), 184-190 hp, introduced as part of the F20/F21 LCI update
F40 generation launches with B47C20A 2.0L turbo diesel, continuing the 120d badge
Current F70 generation continues with updated B-series diesel engines
Key Specs Snapshot
Fuel TypeDieselEngine Size Range2.0L (1,995 cc) across all productionPower Output Range163-190 hp across the variant's historyYears Produced2004-presentEvery engine fitted to the BMW 1 Series 120d is covered below, with UK rebuilt pricing and known failure points.
BMW 1 Series 120d Engine Codes - Specifications & Replacement CostBMW 1 Series 120d Engine Codes - Specifications & Replacement Cost
2.0L Turbo Diesel (2004-2007)
Power Output163 hp (120 kW)Years Fitted2004-2007
Compatible Trim Levels
- 120d
- 120d SE
- 120d Sport
- 120d M Sport (E81/E87)
Find your exact engine code, specs and UK replacement cost guide.
Used
Tested, ready-to-fit engine
£750-£1,200
Reconditioned
Addressed known issues, tested
£1,295-£1,600
Rebuilt
Full teardown, upgraded internals
£1,700-£2,300
Common Failure
The M47 is generally more reliable than its successor, with the timing chain positioned at the front of the engine for easier access. However, high-mileage examples can suffer from turbocharger wear and injector issues. Regular oil changes are critical - the timing chain can begin to wear and eventually fail at around 100,000 miles if oil service intervals are not followed.
The BMW 1 Series 120d has been powered by four different diesel engines across its production life. Early cars (2004-2007) use the M47D20 - a generally reliable unit with the timing chain at the front of the engine. The N47D20 engines (2007-2015) are infamous for timing chain failure - a well-documented weakness that has affected countless BMW diesel owners. Later B47-powered cars (2015-present) are more reliable, with the timing chain moved to the front of the engine, but they have their own issues including EGR cooler failure and DPF clogging. Replacement demand for the BMW 120d is driven primarily by N47 timing chain failure. Every rebuilt engine supplied through EnginesMarket includes upgraded components addressing the original failure points, plus a minimum 12-month unlimited-mileage warranty.
Why the BMW 1 Series 120d N47 Engine Fails Prematurely
Affected Vehicles
BMW 1 Series 120d (N47D20A / N47D20O0 / N47D20O1, 2007-2015)
Typical Failure Mileage
60,000-100,000 miles
Root Cause
The timing chain system on the N47 engine is positioned at the rear, away from regular service reach. The original tensioner was too short and allowed the chain to become slack which would then rub and clatter against the guides. The chain is prone to rattle between 40,000 and 70,000 miles - an indication that it could snap at any moment. When the timing chain does snap, it causes catastrophic engine failure - the pistons lose timing and hit the valves, bending them and damaging the rocker arms.
Why It Happens
The timing chain system on the N47 engine is positioned at the rear, away from regular service reach. The original tensioner was too short and allowed the chain to become slack which would then rub and clatter against the guides. The chain is prone to rattle between 40,000 and 70,000 miles - an indication that it could snap at any moment. When the timing chain does snap, it causes catastrophic engine failure - the pistons lose timing and hit the valves, bending them and damaging the rocker arms.
Dealer (parts + labour)
£1,200-£1,800
Specialist (parts + labour)
£800-£1,300
What it involves
Replace timing chain, tensioner, guides and sprockets
Suitability
Best if caught early - rattle present but engine still running
1 - 2 daysDealer (parts + labour)
£3,200-£4,800
Specialist (parts + labour)
£2,300-£3,800 (matches Section 4 rebuilt pricing)
What it involves
Supply & fit, upgraded timing components, 12-month warranty
Suitability
When chain has snapped or engine is already damaged
1 - 2 daysAll prices are indicative UK market ranges based on current UK specialist supplier data.| Repair Tier | Dealer (Parts + Labour) | Specialist (Parts + Labour) | What It Involves | Suitability | Estimated Time |
|---|---|---|---|---|---|
 Timing Chain Replacement (preventative) Minor | £1,200-£1,800 | £800-£1,300 | Replace timing chain, tensioner, guides and sprockets | Best if caught early - rattle present but engine still running | 1 - 2 days |
 Full Replacement - rebuilt/reconditioned engine Best Value | £3,200-£4,800 | £2,300-£3,800 (matches Section 4 rebuilt pricing) | Supply & fit, upgraded timing components, 12-month warranty | When chain has snapped or engine is already damaged | 1 - 2 days |
Vehicle Value Check
Vehicle Value Check
A typical 2007-2015 BMW 1 Series 120d is currently valued at approximately £3,000-£8,000 depending on mileage, condition and generation [THIRD-PARTY - Auto Trader / Parkers market observation]. This places the 120d in the "repair or used engine typically makes more sense than a full rebuilt unit" bracket for lower-value examples. If your 120d is worth under £4,500 and the engine has suffered catastrophic timing chain failure, evaluate scrap value first - replacement cost may approach or exceed the car's market value. For well-maintained, higher-spec examples (M Sport, low mileage, later generation) worth £6,000+, a reconditioned or rebuilt engine with warranty is a viable investment.
Our Recommendation
Our Recommendation
If you hear the characteristic rattling noise from the timing chain on cold start in your N47-powered BMW 120d, act immediately. An £800-£1,300 specialist timing chain replacement is far cheaper than a full engine rebuild. If the chain has already snapped, the repair bill often exceeds the car's value - in that scenario, compare rebuilt engine prices through EnginesMarket against the cost of replacing the car. For owners planning to keep their 120d for 2+ years, a reconditioned N47 with upgraded timing components and warranty offers genuine peace of mind.
Don't Let Engine Failure Write Off Your BMW 1 Series 120d
The N47 engine in your BMW 120d has a well-known timing chain weakness - but with the right specialist, this can be addressed before catastrophic failure occurs. Later B47-powered cars are more reliable but still benefit from regular maintenance and vigilance for EGR and DPF issues. Whether you need a preventative timing chain replacement or a full rebuilt engine with upgraded components and a 12-month warranty, EnginesMarket connects you with vetted UK specialists who know the 120d inside out. Compare prices today and keep your BMW on the road.
Compare rebuilt N47D20O0 BMW 1 Series 120d engine prices
12-Month Minimum
UK Specialists Vetted
Best Price GuidanceImportant Information
Important Information
"All prices are indicative UK market ranges based on historical quote data and repair requests from our network of engine specialists. Dealer pricing is estimated based on published main dealer labour rates and genuine OEM parts pricing. Specialist pricing reflects actual quote data from EnginesMarket's UK network. Actual costs vary depending on damage severity, vehicle condition, variant, and workshop location within the UK. Use our free comparison tool to get tailored quotes for your specific BMW 1 Series 120d. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited mileage warranty - always confirm exact terms with your chosen supplier."
BMW 1 Series 120d Engine ReplacementFrequently Asked Questions
Question 1How much does a BMW 1 Series 120d engine replacement cost-
A BMW 1 Series 120d engine replacement typically costs £1,295-£3,200 for a reconditioned or rebuilt unit supply-only, depending on the engine code. With supply and fit, expect £2,300-£4,000 depending on the specialist and location.
- Used M47 engines: £750-£1,200
- Used N47 engines: £1,295-£1,800
- Reconditioned N47: £1,295-£1,850
- Rebuilt B47 with warranty: £2,400-£3,200
Question 2What are the signs of timing chain failure in a BMW 120d-
The most common warning signs of N47 timing chain failure in a BMW 1 Series 120d include a rattling noise from the engine on cold start, rough idling, poor engine performance, and in later stages, the engine management light illuminating.
- Rattling noise lasting 1-2 seconds on cold start is the earliest warning
- The N47 timing chain is at the rear of the engine, making inspection difficult
- A snapped timing chain on an N47 engine usually means catastrophic engine damage
Question 3Is it worth replacing the engine in a BMW 1 Series 120d-
A 2007-2015 BMW 1 Series 120d is typically valued at £3,000-£8,000. If your 120d is worth under £4,500, a full rebuilt engine may not be economically viable - consider a used engine or scrap the car. If your car is worth £6,000+ (low mileage, M Sport spec, good condition), a reconditioned engine with warranty is a sound investment.
- Vehicle value is the key factor in the decision
- Used engines offer a budget-friendly alternative
- Rebuilt engines with warranty suit owners keeping the car 2+ years
Question 4How long does a BMW 1 Series 120d engine replacement take-
A BMW 1 Series 120d engine replacement typically takes 2-3 days for a specialist to complete, including removal of the old unit and fitting the replacement. Timing chain replacement alone (without full engine removal) can be completed in 1-2 days.
- Supply-only: engine delivered next working day in many cases
- Supply and fit: allow 2-3 working days
- Mobile fitting options available through some specialists
Question 5What's the difference between the BMW 120d and 118d-
Both the BMW 120d and 118d use the same 2.0-litre diesel engine family but with different power outputs. The 118d produces 122-150 hp depending on generation, while the 120d produces 163-190 hp.
- Same engine families - many parts are interchangeable
- 118d: 122-150 hp, lower torque output
- 120d: 163-190 hp (depending on generation), higher torque output
Question 6Does a BMW 1 Series 120d rebuilt engine come with a warranty-
Yes - every rebuilt BMW 1 Series 120d engine supplied through EnginesMarket comes with a minimum 12-month unlimited-mileage warranty. This covers the engine against manufacturing defects and component failure, giving you peace of mind when investing in a replacement M47, N47 or B47 unit.
- 12-month warranty is standard on all rebuilt engines
- Some specialists offer extended warranty options (6-24 months)
- Always confirm exact warranty terms with your chosen supplier
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