2012 BMW 3 Series

Watch out for

Reputation: what owners and the press report. Tap one to see what to check.

• Timing chain stretch on the N20 four All years

  What to check: Listen for a whine or rattle at a cold start and idle, and ask whether the timing chain, guides and tensioner were replaced with updated parts.

  AutoTrader.ca reports owners of 2012–2014 328is with stretched or failed chains, some losing the engine. Euro Premium Parts says the stretch can break the plastic guides. In one owner forum thread two owners describe a whine after a cold start, a third says a whine comes before failure, and a poster who works at a dealer says many early N20s got new engines. In another, two owners report original chains still fine at about 134,000 miles, and one found the old parts in good order when replacing them at 132,000.

  Sources ^6,7,8,9

• Oil leaks on the N55 six All years One source so far

  What to check: Look for oil around the valve cover, the oil filter housing and the oil pan.

  Euro Premium Parts lists leaks from these gaskets on the N55, and carbon on the intake valves of cars driven mostly in town.

  Sources ⁷

• Coolant leaks on the newer four All years One source so far

  What to check: Look for coolant at the upper radiator hose and the oil filter housing.

  Euro Premium Parts reports occasional leaks at these two points, cheap to fix.

  Sources ⁷

• Automatic gearbox fluid leak All years One source so far

  What to check: Look under the gearbox for fluid, where the wiring plug enters it.

  AutoTrader.ca says a failed seal at the gearbox's electrical connector can leak fluid, and that leaving it can damage the gearbox.

  Sources ⁶

• iDrive glitches and failed lights All years One source so far

  What to check: Try the screen, phone pairing, navigation and reversing camera, and check every headlight and tail light.

  AutoTrader.ca reports owners with iDrive crashing or lagging, and with failed LED tail lights, and says xenon and LED headlights are costly to replace.

  Sources ⁶

• Airbag warning light All years One source so far

  What to check: Make sure the airbag light goes out after starting.

  AutoTrader.ca says some owners blame a faulty seat sensor, often replaced under warranty, and advises having any airbag light fixed before buying.

  Sources ⁶

Recalls

• 13V454000 2012–2014

  The brake vacuum pump may not get enough oil and fail, so the brakes need more force. Widened by 14V627000.¹⁰

• 14V176000 2010–2012

  Bolts in the VANOS valve timing housing can loosen or break, cutting power or stalling the engine.¹¹

• 14V627000 2012–2014

  More cars added to the brake vacuum pump recall, 13V454000.¹⁰

• 15V520000 2012–2015

  Software can switch off the front side marker lights while the parking lights or headlights are on, so the car fails a federal lighting rule.^10,12,13

• 20V017000 2006–2013

  Driver airbag inflators fitted as a stopgap Takata repair can burst as their propellant ages. The airbag is replaced.^{14,15,16,17,18,11}

• 24V513000 2006–2012

  The driver airbag in a replacement sport steering wheel can burst when it goes off. The airbag is checked and replaced as needed.^{14,15,16,17,18,11}

• 24V608000 2012–2016

  A poorly sealed plug on the electric water pump can short-circuit, with a risk of fire.¹⁰

What buyers say

Reputation: what owners and the press report

• Sought after: The six-cylinder 335i and 340i All years

  AutoTrader.ca reports owners calling the six-cylinder's performance excellent and favours a manual 335i, and Euro Premium Parts recommends the 335i and 340i for performance and long life.^6,7

• Avoid: A 2012–2014 328i without timing chain records 2012–2014 Less sought after

  AutoTrader.ca advises against a 2012–2014 328i unless the timing chain work is on record, and Euro Premium Parts lists the N20 cars among those to avoid.^6,7

Before you pay

Open the buyer's checklist

Every warning and recall for this generation, with a box to tick.