Credov's researched list of the 24 faults the Mazda Mazda6 is known for (2012–2016), 19 of them serious or costly. Each one says what to look for when you check the car, so you can spot it before you buy. Not every car has these faults: they are the ones worth checking on this model.
What to look for: Look underneath with a torch for flaking rust or holes around the front control arm mounts, especially the passenger side.
Why it matters: Mazda ran a regional recall on 2009-2010 Mazda6 sold or registered in the US road-salt states because the front crossmember can corrode after exposure to road salt, weakening the passenger-side lower control arm mounting point and unexpectedly changing the steering alignment.
Sources: 1
What to look for: Check the airbag light comes on for a few seconds then goes out, both before and after a short drive.
Why it matters: Mazda recalled 2009-2010 Mazda6 because the protective coating may not have been applied properly to the airbag control unit and moisture can damage it. A failed unit prevents the airbags deploying in a crash, and a lit airbag light is also a WoF failure.
Sources: 1
What to look for: Look under the car ahead of the rear wheels for a dented tank or fuel stains, and smell for fuel.
Why it matters: Mazda recalled these cars twice because a blocked vent line lets the tank pull excessive negative pressure until it cracks and leaks fuel. Once the tank has cracked the fix is a tank replacement, not a hose clean.
What to look for: Check each door shuts with one clean click without slamming, and feel the latch on the door edge is solid.
Why it matters: Mazda recalled 2009-2013 Mazda6 because the three door latch mounting screws can work loose; if all three loosen enough the latch will not engage and the door can open while driving.
Sources: 1
What to look for: Drive it up a motorway on-ramp and feel for power fading or warning lights, then check the engine bay for smoke.
Why it matters: The Australian register records that carbon deposits accumulate in the intake shutter valve and certain engine components wear early, producing power loss, longer stopping distance and possible stall with no restart. The remedy includes an ECM software update as well as inspection and repair, so an import with no campaign record has not had either.
Sources: 1
What to look for: Ask if it has ever cut out while driving, and check the service book for the engine software update.
Why it matters: Mazda recalled 2018-2019 CX-5 and Mazda6 and 2019 Mazda3 because a PCM software error may cause the engine to stall. The remedy is a free reflash at a Mazda dealer, so this is cheap to close out - but an unremedied import can stall in traffic.
Sources: 1
What to look for: Listen for long cranking on a hot restart after ten minutes off, and ask for the fuel pump recall record.
Why it matters: Both regulators recorded this: the impeller inside the low-pressure fuel pump can crack and deform, the pump stops working and the car stalls. It spans seven model lines across the 2017-2020 build years, and the remedy is a free pump replacement at a Mazda dealer, so check the campaign status rather than assume it was done.
What to look for: Look along the engine drive belt with a torch for glazing, cracks or looseness, and ask for the software update record.
Why it matters: Mazda recalled 2014 Mazda3 and 2014-2015 Mazda6 with the 2.5 and regenerative braking because a belt slipping in heavy rain or deep water makes the PCM assume the charging system has failed. The car then stops charging, and the consequence listed is poor acceleration, loss of steering assist and wipers, and possible stall. NZ winter road conditions are exactly the trigger.
Sources: 1
What to look for: Check the plate on the NZTA recall check, watch the passenger airbag light, and ask for proof the inflator was replaced.
Why it matters: NZTA's entry-inspection bulletin says vehicles flagged with an open airbag recall must be rejected at entry inspection unless irrefutable evidence is provided from the manufacturer that the affected airbags were replaced, and that from 31 May 2018 alpha inflators are prohibited imports and prohibited for sale in trade.
What to look for: Park on a slope, apply the park brake, and feel the rear wheels after the drive for one hotter than the other.
Why it matters: A seized or dragging rear caliper wears the pads and disc fast and can overheat the brake, while a park brake that no longer holds on a slope is a real safety risk. Both are cheap to catch with a slope test and a feel of the wheels after the drive.
What to look for: Listen for a metal clack while working the seat height lever and rocking your weight in the driver's seat.
Why it matters: Both the US and Australian regulators recorded this recall: the lifter link can crack or its retaining nuts separate, and in the worst case the seat moves out of position while driving. Only cars with the manual seat lifter are covered.
What to look for: Check the park brake holds on a slope and releases cleanly every time, and listen for a rear brake dragging.
Why it matters: Mazda recalled these cars because water can enter the caliper and corrode the parking brake actuator shaft until it binds. A brake that will not release drags and cooks the rear pads and disc; one that will not engage lets the car roll away on a slope.
Sources: 1
What to look for: Look at the mirror base for an unplugged connector, browning or burnt smell, and check the glass darkens under torchlight.
Why it matters: Mazda filed two recalls with MLIT over this mirror. Under 3964 the cause could not be identified and the interim measure was to unplug the mirror connector; under 3971 the cause was traced to foreign matter on the internal board and the mirror was replaced. The circuit can short, melt the resin and give off smoke, and the control fuse can blow so the engine will not start.
What to look for: Feel for a thump or flare shifting 1st-2nd and 2nd-3rd, worse when cold, and slipping on hills.
Why it matters: Owner reports and complaint data describe the same pattern on this automatic: shifts getting rougher with age, old unchanged fluid making it worse, and a used gearbox often being the only fix once it slips. Checking the fluid-change history and feeling the shifts avoids buying a car close to a gearbox replacement.
What to look for: From a stone-cold start, listen at the engine's timing end for a rattle that lasts a few seconds.
Why it matters: Left alone, a stretched chain or worn VVT gear can jump timing; on these engines that lets the valves hit the pistons and destroys the engine. Owners have reported engines failing at 145,000-250,000 km after exactly this rattle was ignored, so an early chain-and-tensioner job is far cheaper than the alternative.
What to look for: Pull the dipstick: sludgy, gritty or strong-smelling oil points to carbon blocking the oil pick-up.
Why it matters: Once carbon blocks the oil pick-up the engine runs with no oil pressure and is usually destroyed, even on a well-serviced car, turning a cheap injector-seal job into an engine replacement. Oil condition and service history are the only warning most buyers get.
What to look for: Check the coolant tank level and the oil filler cap for a milky film, and watch for white exhaust smoke.
Why it matters: A cracked head lets coolant mix with the oil, which wrecks bearings if driven on, and owners and complaint data report repairs of US$5,000-11,000 when not covered by warranty. Checking the coolant and oil now catches it before a short drive turns into an engine job.
What to look for: Check the coolant tank for a tide line, and smell for sweet coolant at the back of the engine.
Why it matters: Coolant loss on this engine often ends up contaminating the oil, and the usual repair is a full engine or long block rather than just the head, with out-of-warranty quotes in the thousands. A coolant and heater check before buying is far cheaper than finding out on the side of the road.
What to look for: Pull the dipstick on level ground: oil at or above the upper mark, or smelling of diesel, is a bad sign.
Why it matters: Diluted oil is thin and lubricates poorly, and has been blamed for turbo, camshaft and bearing damage, in some cases a full engine replacement. A dipstick check and a question about how the car is driven cost nothing and catch this before it wears the engine out.
What to look for: Check the battery label says Q85 or T110, not a generic battery, and that the engine cranks briskly.
Why it matters: Mazda published specific handling, inspection and charging procedures for the Q85/T110 because leaving the battery discharged for long periods can cause battery failure, and it specifies an operation that must be carried out after the battery is replaced. Check what battery is actually fitted and whether that post-replacement step was done, rather than assuming a recent battery change was completed to spec.
Sources: 1
What to look for: Listen at the engine front on a cold start for a rattle or grind from the alternator that changes with revs.
Why it matters: Mazda published a warranty extension in Japan stating that the grease sealed inside the alternator pulley on diesel cars is not heat-resistant enough, that repeated low-speed acceleration and stop-start use degrades it early, that noise develops, and that the pulley then fails so the alternator stops charging and the charge lamp comes on.
Sources: 1
What to look for: Check both mirrors fold in and out fully and evenly, twice, watching for one that is slow, stops or judders.
Why it matters: Mazda published a warranty extension in Japan stating that the power-fold mirror is not waterproof enough against high-pressure washing, that water gets into the fold unit, and that the sliding parts then stop working so the mirror will not fold or unfold electrically. Cover was extended from 3 years / 60,000 km to 5 years with no distance limit.
Sources: 1
What to look for: Look along the bonnet, bumper and mirrors for chips, and check the bonnet colour matches the guards.
Why it matters: Mazda's soft, multi-layer paint chips more than most, and the tinted reds cost more to colour-match and repair than a solid colour, so heavy chipping or a repainted, mismatched bonnet is a real cost to budget for or negotiate off the price.
What to look for: Check the service history line by line for any gearbox flush, oil additive or engine flush.
Why it matters: Mazda's own scheduled maintenance bulletin states that transmission flushing should only be performed when instructed by the workshop manual, that transmission fluid replacement is only recommended on B-Series and Tribute, that transmission oil additives could lead to internal damage and void the warranty, and that engine oil flushes are unnecessary.
Sources: 1
Got a question about a Mazda Mazda6? Ask Credov: a noise, a warning light, a part or how to fix it.
On top of the faults above, every Credov inspection covers the basics: fuel smell, leaks or filler rust, engine oil leaks, power steering fluid leak, drive belt cracks or squeal, rust underneath: chassis and mounts, engine mounts, engine oil level and colour, coolant level, colour and leaks, head gasket failure signs, cold start: rattle, knock or smoke, rough or hunting idle, engine running hot on gauge, gearbox or diff oil leak, swapped gearbox without lvv and more.
Researched by Credov from manufacturer recalls and service bulletins, owner reports and workshop sources. Repair prices are typical ranges, not quotes. See also fault codes and repair costs.