BMW 1 Series 118i Executive common faults.

2004–2007, hatchback, petrol, 129 HP.

The fault list covers: N46B20, N43B20 engine, GS6 transmission.

What you save stays on this device only. My saves

5 fault write-ups. All are important. 13 recalls.

If you know the year, pick it. Faults for other years drop out of the list.

Before you buy

Known faults

5 important faults

critical2

Electric water pump: silent failure, immediate overheating

critical

In these engines the water pump is not belt driven but has its own electric motor. It gains on fuel consumption, but it opens a new failure path: the pump or its electronics often simply stops with no warning. Measured in the official complaints, the typical mileage is 161,000 km (a tenth of the complaints already at 81,000, a tenth only above 257,000 km). So the common wisdom of "around 100,000 km" is early: most of the failures happen between 130,000 and 250,000 km.

Show the rest

With a belt driven pump the flow weakens gradually, here the circulation stops in an instant. In urban traffic the temperature crosses the limit within minutes, the cylinder head distorts, and the repair is an engine rebuild.

Replacing a still good pump at around 120,000 to 150,000 km costs less than repairing an overheated engine. If the replacement is already in the service book, the pump has already been changed.

between 81,000 and 257,000 km

What to check

Watch the coolant temperature gauge after startup: it should settle evenly, not jump around
Standing still with a warm engine, listen for whether the cooling fan and the pump are working
Ask for a fault code read: codes pointing at coolant flow belong here

2 more steps in the write-up

N43: plastic chain guide breaks and the debris blocks the oil pickup

critical

On the N43 direct injection four cylinder the plastic guides of the timing chain can break. The broken pieces fall into the sump and block the screen of the oil pickup. From then on the engine is starved of oil, and that takes out the bearings first.

Show the rest

If the chain is rattling, the debris may already be on its way to the oil pickup, so leaving the replacement for later is not enough.

On the same engine the injectors, the ignition coils and the NOx sensor can fail too.

What to check

Identify the engine first: a 320i/318i from 2005 to 2011 can be an N46 (port injected) or an N43 (direct injection). If the version does not show which engine is fitted, the build date and the engine number decide. The N43 arrived in 2007, and this fault applies only to the N43
On a cold start listen to the front of the engine: rattling or clicking from the timing chain
Ask whether the oil pressure light has ever come on, even for a moment

3 more steps in the write-up

expensive3

VANOS solenoid valve: a clogging filter screen and late camshaft adjustment

expensive

VANOS adjusts the position of the camshaft with the pressure of the engine oil, and a solenoid valve metres that pressure. The valve sits in the oil circuit, and a fine filter screen protects the spool inside it from larger particles. That screen clogs with carbon and deposits: less oil flows through, and VANOS then adjusts late or does not move at all. The symptoms are a rough idle, rough running, a lack of torque at low revs and higher fuel consumption, because the valve timing is off. A short metallic clacking can also come on a cold start and goes quiet after 10 to 20 seconds. The engine warning light comes on with a camshaft fault code, and depending on the severity the engine control unit switches to limp mode. The fault code narrows down the cause. P0010 and P0013 typically mean the solenoid valve itself, that is a circuit fault or reduced oil flow through the clogged screen. P0011 and P0014 point more to a mechanical cause: a stretched timing chain or a worn adjuster. P0012 and P0015 report late camshaft control, whose common cause is slow pressure build-up at the adjuster, so again the dirty valve. The valve itself is a small part, between 50 and 120 euro, and with a clean screen cleaning is often enough; replacing the whole adjuster, by contrast, is a four-figure job. The reported repairs ran between 80 and 1,200 euro, depending on whether cleaning is enough and how many valves are affected. The main cause of the screen clogging is a stretched oil change interval and carbon-laden oil.

between 70,000 and 120,000 km80–1,200 EUR

What to check

Read the fault memory and note the exact code: P0010 and P0013 point to the valve
If P0011 or P0014 is stored, the timing chain has to be checked as well
Start the engine cold and listen for metallic clacking in the first 10 to 20 seconds

2 more steps in the write-up

Crankcase ventilation (CCV) in the valve cover: oil consumption, rough running

expensive

The crankcase ventilation leads the gas that forms in the crankcase back to the intake and separates the oil out of it on the way. If the system clogs or the membrane tears, the pressure cannot get away: it finds a way out past the seals, or it pushes the oil through the piston rings. This is where the oil consumption comes from, and the oil that appears around the valve cover gasket. In the other direction a faulty breather takes unmetered air into the intake, and that is what makes the idle rough, the throttle response hesitant and the running coarse. Starting also gets harder, and in an extreme case the engine stalls at idle. Two characteristic signs help: weak or absent suction at the oil filler with the engine running, and noticeably rough running around 3,000 rpm. The hose at the rear of the valve cover can also let oil out. The sound insulation then soaks itself with oil, and oil gets everywhere in the engine bay. On the six-cylinder engines the breather is built into the valve cover, so the repair is replacing the cover or the whole oil separator together with the hoses, between 80 and 900 euro.

between 80,000 and 150,000 km80–900 EUR

What to check

With the engine running unscrew the oil filler cap: weak or absent suction is a sign
Look around the valve cover and at the rear of the engine bay for oil traces
Watch the idle, and the rough running around 3,000 rpm

2 more steps in the write-up

N43 / N53 lean burn petrol: injectors, ignition coils, NOx sensor

expensive

The N43 (four cylinder) and the N53 (six cylinder) are direct injection petrol engines built for lean burn operation. Lean burn demands far more of the injection system than a conventional port injected design, and these are exactly the three parts that gave trouble in service: the injectors, the ignition coils and the NOx sensor.

Show the rest

You notice this as a rough, uneven idle, hesitation on a cold start, loss of power and higher fuel consumption. A faulty NOx sensor on its own also raises consumption, because the control unit then fuels for the worst case.

The piezo injectors are expensive each, and when one fails the replacement rarely stops at one. The N53 also uses the same high pressure pump as the N54, where pump failures led to litigation in the USA. Pump failures were reported on the N53, but it is not known whether they are as frequent as on the N54 (the N53 was not sold in the USA, so there is no official complaint data on it).

What to check

Identify the engine first: a 320i/318i from 2005 to 2011 can be an N46 (port injected) or an N43 (direct injection). If the version does not show which engine is fitted, the build date and the engine number decide. The N43 arrived in 2007, and this fault applies only to the N43
After a cold start listen to the idle for at least a minute: shaking, misfire, fluctuating revs
Ask for a fault code read specifically for misfire (per cylinder) and for the NOx sensor

4 more steps in the write-up

Official recall13 recallsShow

The manufacturer fixes these for free at a franchised dealer. Ask with the VIN whether it was done.

Most recent: 31 October 2025

SR/01914/26Safety recallInjuries31 October 2025 · EU Safety Gate

The propellant in the driver airbag may deteriorate over time. If the airbags deploy, it could result in fragments from the inflator injuring the vehicle's occupants. The product does not comply with the Regulation on the approval and market surveillance of motor vehicles and their trailers, and of systems, components and separate technical units intended for such vehicles.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: 31/10/2025

We could not check this: model year. The authority's notice

SR/01940/26Safety recallInjuries19 March 2025 · EU Safety Gate

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: 19/03/2025

We could not check this: model year. The authority's notice

A12/01929/23Safety recallInjuries29 June 2021 · EU Safety Gate

The propellant in the driver airbag can deteriorate due to high humidity and temperature variations. In the event of an accident in which the airbag deploys, this could result in fragments from the inflator casing coming loose and injuring the vehicle’s occupants. The product does not comply with the Regulation on the approval and market surveillance of motor vehicles and their trailers, and of systems, components and separate technical units intended for such vehicles.

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: 29/06/2021

We could not check this: model year. The authority's notice

A12/01930/23Safety recallInjuries29 June 2021 · EU Safety Gate

Remedy: Type of economic operator taking notified measure(s): Manufacturer Category of measure(s): Recall of the product from end users Date of entry into force: 29/06/2021

We could not check this: model year. The authority's notice

10V254000SEAT BELTS:FRONT:RETRACTORSEAT BELTS:FRONT:RETRACTOR10 June 2010 · NHTSA (USA)

BMW IS RECALLING CERTAIN MODEL YEAR 2008-2011 1-SERIES VEHICLES. IN A CRASH OF SUFFICIENT SEVERITY, DEPLOYMENT OF THE FRONT PRE-TENSIONER AND LOAD-LIMITER OCCURS.

Risk: THE INSULATION AROUND THE PRE-TENSIONER COULD IGNITE.

Remedy: VEHICLES PRODUCED UP THROUGH DECEMBER 2009 WILL RECEIVE NEW FRONT SAFETY BELT RETRACTOR UNITS AND A MODIFICATION TO THE SOUND INSULATION NEAR THE UNITS, WHILE VEHICLES PRODUCED BETWEEN JANUARY 2010 AND MAY 2010 WILL RECEIVE A MODIFICATION TO THE SOUND INSULATION NEAR THE UNITS. THIS SERVICE WILL BE PERFORMED FREE OF CHARGE. THE SAFETY RECALL BEGAN ON AUGUST 23, 2010. OWNERS MAY CONTACT BMW AT 1-800-525-7417.

We could not check this: model year. The authority's notice

A12/00039/20Safety recallInjuriesno date · EU Safety Gate

The connector of the positive battery cable on the front power distribution box may be damaged over the lifetime of the vehicle by vibrations and currents. This may lead to failure of the engine and of the vehicle's electrical system, including headlights and occupant protection which will increase the risk of an accident and injuries to the occupants.