Mazda Demio common problems: what to check before you buy
Credov's researched list of the 18 faults the Mazda Demio is known for (2014–2018), 12 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.
Known problems on the Mazda Demio
Front strut bolts working loose
Safety risk
2013–2016 · Suspension and steering
What to look for: Look behind each front wheel at full lock for shiny marks or misaligned paint on the two lower strut bolts.
Why it matters: Mazda recalled a small number of these cars (578 in the US campaign) because the lower strut mounting hardware can loosen and let the steering knuckle separate from the strut, which is a total loss of steering control on that corner. A workshop torque check is quick, so rule it out rather than assume it.
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: 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: Smell for diesel and look for a wet film where the fuel pipe meets the engine, before and after the drive.
Why it matters: Mazda told MLIT the connector bolt on the engine fuel pipe was not tightened properly in production, so it can work loose and let fuel out, with a fire as the worst case. The remedy replaces the pipe, packing and bolt and retorques them, so an untouched car keeps the original risk.
What to look for: Check the i-ELOOP and i-stop warning lights go out after start-up, and ask if the battery has been going flat.
Why it matters: Mazda told MLIT that the DC-DC converter control program was wrong: when the electrical circuit fails, the i-ELOOP warning lamp lights and the i-stop warning lamp flashes and a bypass mode cuts the current, but pressing the push-button start to switch the power off can cancel that bypass. The internal circuit then shorts, charging fails, the battery goes flat and the engine stops, with a fire as the worst case.
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 for an engine light or flashing glow-plug light, feel for shaking or lack of pull, and ask for recall stamps.
Why it matters: Mazda told MLIT that on the 1.5 SkyActiv-D, repeated low-speed stop-start driving builds soot around the exhaust valve guides, the exhaust valves stop moving freely, compression falls, and the engine can stop while the car is being driven.
What to look for: Ask for the Japanese service book and look for an engine software recall entry dated February 2018 or later.
Why it matters: Mazda's notice states that the engine protection control was set up so that, with the accelerator held wide open under no load, abnormal combustion does not trigger the protection function; combustion pressure then rises and the engine can be damaged. Buyers of imports often assume a Japanese recall follows the car automatically, and it does not.
What to look for: Look and feel around the fuel filter drain plug for a dark wet diesel film, and smell for diesel.
Why it matters: Mazda told MLIT the drain plug mounting face was not flat, so a plug tightened hard in production could deform or crack the gasket, and fuel can leak either in service or after the plug is loosened and retightened at a scheduled service. A car that has had a Japanese service since the recall, without the corrected parts, is the one most likely to weep.
What to look for: Look along the engine belt for cracks, glazing or missing ribs, and check the charge light goes out and stays out.
Why it matters: Mazda's notice to MLIT says the belt core wire tension was uneven in manufacture, leaving some belts weak; the belt can break, which stops the alternator and the water pump, lights the warning lamps, and can leave the car unable to restart. A replacement belt from a Japanese workshop is not proof the recall part was fitted.
What to look for: Pull the dipstick for oil above the full mark or smelling of diesel, and watch for a flashing DPF light.
Why it matters: Oil diluted by diesel is thin and wears the engine and turbo faster, and a DPF that cannot finish regenerating can need a forced regeneration, a professional clean or a new filter, so the dipstick and the DPF light are worth checking on any short-trip diesel of this family.
What to look for: Watch for the glow-plug light flashing, and listen at idle for one cylinder knocking louder than the others.
Why it matters: Driving on with a failed injector risks fuel further diluting the oil and damaging the engine, and a full set of injectors is a big bill, so the glow-light and idle-knock checks are worth doing on any diesel Demio or Mazda2 of this generation.
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.
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.
What to look for: At walking pace turn the wheel lock to lock, with and without the brake on, and feel for a notch or clunk.
Why it matters: This is a very common complaint on this model, and while most cases are only a shaft replacement or re-grease, heavy play should be checked before assuming it is only the shaft, so a proper lock-to-lock test is worth doing on every DE Demio or Mazda2.
2007–2014 · ZJ-VE, ZJ-VEM, ZY-VE · petrol · Engine
What to look for: After 20 minutes of driving, sit in Drive at the lights and watch the tacho for a dip below 600 rpm.
Why it matters: This is a very common complaint on this model that is easy to mistake for a CVT fault, so a proper 20-minute warm-up before judging the idle is the only reliable way to catch it on a test drive.
What to look for: Look at the screen edges in daylight for white cracks or bubbles, and watch for menus changing by themselves.
Why it matters: A cracked or hanging touchscreen is annoying rather than dangerous, but replacing just the touch glass is much cheaper than a whole head unit, so spotting it early is useful for negotiating 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.
Got a question about a Mazda Demio? Ask Credov: a noise, a warning light, a part or how to fix it.
Also check on every car
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.