Mazda Roadster common problems: what to check before you buy
Credov's researched list of the 14 faults the Mazda Roadster is known for (2005–2015), 10 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 Roadster
Fuel pump fault and hot restart
Safety risk
2017–2020 · petrol · Engine
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: 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: Feel for a sudden lurching downshift when coasting downhill or off the throttle, and ask for the gearbox software update.
Why it matters: Mazda recalled 2016-2019 automatic MX-5 because incorrect TCM programming can cause an unexpected downshift and abrupt deceleration, with a risk of losing control. It is a free reflash, so an unremedied car is an easy win to close out before sale.
What to look for: Feel the front carpets, especially the passenger side, for damp and look behind the kick panel for water stains.
Why it matters: UK owners say every NC will eventually leak here, and water damage already done to modules or wiring costs far more than the cheap grommet reseal, so catching it with damp carpets or a corroded fuse box before buying is valuable.
What to look for: Feel inside each rear wheel arch lip and the underside of the sills for bubbling, flaking or soft metal.
Why it matters: A neglected NC can need welding to the sills or a subframe swap, which is a major repair on a car this small, so a careful torch check of the rust-prone spots before buying is well worth the few minutes it takes.
What to look for: Run the roof fully down and up twice and watch for smooth movement with no grinding or constant beeping.
Why it matters: Most roof faults are only an adjustment or a switch clean, but the motors and control module are expensive, so running the roof through its full cycle twice before buying is the cheapest way to find a problem.
What to look for: Look closely at the expansion tank neck with a torch for hairline cracks or crusty coolant tracks.
Why it matters: Because the gauge gives so little warning, a cracked tank has caused warped heads and blown gaskets on this model, so a close torch look at the tank neck is far more reliable than trusting the dash gauge during a test drive.
What to look for: Fold the roof down and look for a clear gap to the roll-hoop covers, and check for fraying or holes.
Why it matters: A worn hole in the roof fabric is a weatherproofing problem as well as a cosmetic one, and a replacement genuine top is expensive, so checking the hoop gap and the fold lines for fraying is worth doing before buying any soft-top ND.
What to look for: Fully warmed up, change through every gear slowly and quickly, including 1-2, 2-3 and a downshift to third.
Why it matters: A damaged gearbox on this model can need a full replacement, which is expensive, so a thorough, fully-warmed-up run through every gear on the test drive is the best way to catch grinding, whining or baulking before buying.
What to look for: Look underneath with a torch for an underbody cover that sags, is tied up, or has rust at its brackets.
Why it matters: Mazda told MLIT the jig controlling the bond between the under cover and its bracket was not managed properly, so the bond is weak; heavy vibration or corrosion from de-icing salt separates it, a noise develops and the bracket can fall off into the path of other traffic. Japanese cars from snow regions get de-icing salt, so an import from those prefectures is more exposed than a New Zealand car.
What to look for: In good light look across the RHT roof, rear deck and mirror covers for fading, a milky haze or blistering.
Why it matters: Once the clear coat lifts, moisture keeps getting underneath and the panel keeps blistering, so a roof or deck that already shows haze or blisters is heading for a full repaint of those panels rather than a touch-up, and the plastic panels need careful drying before repainting or it bubbles again.
Typical repair: NZ$400–NZ$2,500 in New Zealand · A$410–A$2,580 in Australia
What to look for: Look at the outer edge of the driver's seat for cracking or wear, and compare with the passenger seat.
Why it matters: A trimmer replacing the bolster panel, or reupholstering the seat, is the real fix once it has cracked or worn through, so a badly worn bolster on an otherwise tidy car is a cost to budget for even though it is cosmetic.
Typical repair: NZ$150–NZ$500 in New Zealand · A$150–A$520 in Australia
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 Roadster? 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.