Car Model Guide/ BMW/ 1 Series/ E82/ 118i

118i N43

Lean-burn direct-injection four. Economical when healthy and expensive when not. The injectors and NOx sensors are the whole story.

Overview

The 118i is the N43 petrol version of the BMW 1 Series coupe (E82), sold 2007–2011 with 143 PS and manual or automatic. Demands diligence at level 3. Piezo injectors and NOx sensors are the recurring cost, on a car whose value doesn't cover many of them. 9 failure modes are recorded against its engine, gearbox, chassis and shared components. Prices on this page are illustrative placeholders rather than a sourced market sample. See the methodology for how the bands are derived.

BMW 1 Series coupe (E82) · photo 2008-2010 BMW 125i (E82) coupe 01 by OSX · Public domain · Wikimedia Commons

Power143 PS

Torque190 Nm

Years2007–2011

Fuelpetrol

DriveRWD

EnginesN43

Biggest risks

Ranked by probability × repair cost. 9 recorded in total.

52Demands diligence

"Lifetime" fluid neglect€400–€2,500partly checkable
Dual-mass flywheel and clutch wear€900–€1,600checkable
Carbon buildup on intake valves€400–€700not checkable

Risk level −22 · Likely spend vs price −26 · all issues →

System by system9 systems reviewed · 2 with no recurring fault reported

EnginewatchTiming chain tensioner rattle, €300–€1,400.

Fuel systemwatchPiezo injector failure (lean-burn petrol), €350–€500.

Intake & airwatchCarbon buildup on intake valves, €400–€700.

Cooling✓ clearNo recurring fault reported for this system on this engine.

EmissionswatchNOx sensor failure, €300–€600.

Transmission⚠ attention"Lifetime" fluid neglect, €400–€2,500.+2 more in this system

ElectricswatchWater ingress and footwell module damage, €0–€1,200.

Suspension & brakeswatchRear trailing-arm and subframe bush wear, €150–€500.

Body & interior✓ clearNo recurring fault reported for this system on this engine.

Pre-facelift or facelift, this engine spans both

The same badge either side of the changeover. Bands are split at the facelift year from the generation record.

Phase	Years	Low	Average	High	Good buy	What differs
pre Pre-facelift	2007–2010	€3,250	€4,700	€6,700	€4,000	The specification the car launched with.
LCI Facelift (LCI)	2011	€3,550	€5,150	€7,300	€4,350	N55 single-turbo replaced the N54 twin-turbo in the 135i; Revised lights, bumpers and interior

Known issues, ranked by expected cost

Faults recorded against this engine, its components and its chassis, ranked by likelihood × repair cost. Costs are indicative ranges with a stated labour basis.

"Lifetime" fluid neglectZF 6HP19 / 6HP21 six-speed automatic€400–€2,500

Harsh or hunting shifts, a shunt between second and third, delayed engagement when cold. BMW declared the fluid a lifetime fill. It's not. Fluid degrades, the valve body wears, and the box eventually fails.

Check: Drive it from cold through every gear, then in manual mode. Ask when the fluid was last changed. "It's sealed for life" means never, and you should price a service in.

TransmissioncommonPartly detectableevidence: documented120–200k km

Dual-mass flywheel and clutch wearGetrag six-speed manual€900–€1,600

Rattle at idle with the clutch up that disappears when you press it, judder on pull-away, gearbox rumble. The dual-mass flywheel's springs wear. Diesels and tuned petrols wear them faster.

Check: Idle in neutral with the clutch up and listen, then press the clutch. A rattle that stops when you press is the flywheel. Also check for judder pulling away in first.

TransmissioncommonDetectable at viewingevidence: documented130–250k km

Carbon buildup on intake valvesdirect injection€400–€700

Rough cold idle, slow throttle response, misfires, gradual loss of low-end response. Direct injection puts no fuel over the intake valves, so crankcase vapour deposits bake on undisturbed.

Check: Not visible without a borescope. Treat it as a service item that's due unless there's a receipt. It's not a fault, it's an unbudgeted maintenance cost.

Turbo & intakeuniversalNot detectable at viewingevidence: documented80–120k km

Timing chain tensioner rattleN43B20€300–€1,400

Rattle for one to three seconds on cold start, worst after the car has stood overnight. The hydraulic tensioner bleeds down. Caught early it's a tensioner; ignored it becomes chain and guides.

Check: The car must be stone cold. Stand outside it at start-up and listen for a rattle from the front of the engine.

EnginecommonDetectable at viewingevidence: documented100–180k km

Water ingress and footwell module damage1 Series platform€0–€1,200

Damp or soaked front carpets, a musty smell and fogged windows, and, when water reaches the footwell electronics, failed lights, windows or indicators. Most often the bulkhead scuttle drains block by the pollen filter and overflow into the cabin; perished door membranes and tailgate seals can add to it. Water then attacks the footwell module.

Check: Lift the front and rear carpets and press for damp. Check the boot and spare-wheel well for standing water, and confirm the scuttle drains near the pollen filter are clear.

ElectricalcommonDetectable at viewingevidence: documented60–200k km

NOx sensor failureNOx sensor€300–€600

Engine warning light, noticeably worse fuel consumption, loss of lean-burn mode. The NOx sensor in the exhaust degrades. The engine then runs permanently rich, which is drivable but expensive.

Check: Scan for NOx sensor and lean-mode codes. Ask the seller what the car returns on a run. A lean-burn four that drinks like a six has a dead sensor.

EmissionscommonDetectable at viewingevidence: documented90–180k km

Piezo injector failure (lean-burn petrol)piezo injectors€350–€500

Rough idle, shaking at standstill, misfire warnings, poor cold running, sometimes limp mode. The stratified-charge petrol engines use piezo injectors that are sensitive to fuel quality and wear out. They typically fail one at a time over several years.

Check: Scan for per-cylinder misfires and check how many injectors have already been replaced. A car with all six done recently is worth a real premium over one with none.

FuelcommonPartly detectableevidence: manufacturer80–160k km

Mechatronic sleeve and pan gasket leakZF 6HP19 / 6HP21 six-speed automatic€250–€600

Fluid on the bellhousing or the exhaust, gearbox fault warnings, erratic shifting once the level drops. The plastic adapter sleeve carrying the wiring through the case hardens and leaks; the integrated pan gasket does the same.

Check: On the lift, look at the gearbox pan and the bellhousing seam for wet ATF, it's red-brown and unmistakable.

TransmissioncommonDetectable at viewingevidence: documented120–220k km

Ranked by probability × repair cost, not by how loudly a failure is discussed. Inherited from the engine, gearbox, chassis and shared components, each written once. All 9 issues in full →

Pre-purchase inspection

The same issue records, reordered into the sequence you can actually check them in: cold start, static, drive, paperwork.

9 checks · saved in this browser ·

1Cold startYou get one. If the engine is warm when you arrive, come back another day.

Timing chain tensioner rattleThe car must be stone cold. Stand outside it at start-up and listen for a rattle from the front of the engine.

2Static checksEngine off, ideally on a lift.

Water ingress and footwell module damageLift the front and rear carpets and press for damp. Check the boot and spare-wheel well for standing water, and confirm the scuttle drains near the pollen filter are clear.Mechatronic sleeve and pan gasket leakOn the lift, look at the gearbox pan and the bellhousing seam for wet ATF, it's red-brown and unmistakable.Rear trailing-arm and subframe bush wearOn a ramp, lever the rear bushes for splitting and check the subframe mounts for corrosion; on the road. Listen for a rear knock and check for even tyre wear.

3On the driveInclude low-speed manoeuvring, not just an open road.

"Lifetime" fluid neglectDrive it from cold through every gear, then in manual mode. Ask when the fluid was last changed. "It's sealed for life" means never, and you should price a service in.Dual-mass flywheel and clutch wearIdle in neutral with the clutch up and listen, then press the clutch. A rattle that stops when you press is the flywheel. Also check for judder pulling away in first.

4PaperworkOn these cars the folder is most of the value.

Carbon buildup on intake valvesNot visible without a borescope. Treat it as a service item that's due unless there's a receipt. It's not a fault, it's an unbudgeted maintenance cost.

5OBD scanMandatory. A seller who refuses a scan has answered the question.

NOx sensor failureScan for NOx sensor and lean-mode codes. Ask the seller what the car returns on a run. A lean-burn four that drinks like a six has a dead sensor.Piezo injector failure (lean-burn petrol)Scan for per-cylinder misfires and check how many injectors have already been replaced. A car with all six done recently is worth a real premium over one with none.

Mileage and servicing

What the odometer does and doesn't tell you here, plus the service items whose neglect causes the expensive failures above.

Scan for injector and NOx faults rather than trusting the mileage. Injector index history is the number that matters.

Service item	Interval	Cost
Engine oil Injection-system longevity follows oil quality	12,000–15,000 km	€90–150
Injector/NOx scan The only honest read on the fuel system	on purchase	free

What to pay

What this engine sells for, against the median of every engine in the chassis. All figures are illustrative placeholders. See the basis chips.

median €5.0k

€3.3k€4k€7.3k

Cheapfind the reasonGood buyif it checks outFairnormal moneyOverpricedneeds justifying

Asking price (€)Mileage (km)

Enter an asking price to get a verdict against this variant's band: cheap, fair, good buy or overpriced.

United States vs Europe

1 EUR = 1.08 USD · 2026-07

🇪🇺 Europe · EUR€4,000band €3,250–€7,300

🇺🇸 United StatesNot sold118i N43 was never a US-market car

What that meansNo US band exists to compare. Any car you find there's a private import, parts and specialist knowledge are thinner, and the price says more about import cost than about the market.

US figures are the EU band converted at a stated rate. No US market differential is modelled: we hold no sourced US asking prices, and inventing one would be worse than saying so. What the comparison does show for real is availability. Most of this range was never sold in the US.

ModelBMW 1 Series 118i
ChassisE82
EngineN43
Years2007–2011
MarketCentral EU
Windowrolling 12 months to 2026-07

Good buy at or under the marker · Median asking price · bar spans the 10th to 90th percentile · dashed line is the e82 median, all 9 engines

Good buy isn't the same as cheapest. The good-buy figure assumes the known failure items are either done with receipts or verifiably not yet due. Full breakdown by facelift phase →

Buyer notes

Our judgement, kept separate from the records it's built on.

Our read, not a record

The N43 118i is the mainstream facelift petrol and a good car with one running-cost asterisk. The piezo injectors and NOx sensors that make it economical are also what make it expensive when they fail. Then budget for them, buy one with evidence they've been addressed, and it's a fine everyday choice. Ignore the fuel system and it becomes a limp-mode car with a €2,000 quote.

Everything above this line comes from the issue and specification records. This paragraph is our judgement on top of them. See how we reach it.

Full specification

Manufacturer figures for this engine and body, as recorded in the variant and engine data.

Engine code	N43B20
Configuration	I4, naturally aspirated, lean-burn · 1995 cc
Fuel / injection	petrol · direct
Model years	2007–2011
Facelift phase	Sold either side of the 2011 facelift, 2007–2010 pre, 2011 LCI
Power / torque	143 PS · 190 Nm
Transmissions	6-speed manual · 6-speed automatic (ZF)
Gearbox families	Getrag six-speed manual · ZF 6HP19 / 6HP21 six-speed automatic
Drivetrain	RWD
Economy (real-world)	6.5–8 l/100 km mixed
Markets	EU