4 Common Issues With The Mazda Miata (According To Owners)

What can go wrong when you own a happy-looking car with pop-up headlights? Apparently quite a bit, if you ask Mazda MX-5 Miata owners. But in the end, it's all worth it. The Miata is the world's best-selling roadster thanks to its adorable appearance, excellent handling, and how fun it is to drive — SlashGear even named it one of the best canyon-carving cars out there. And okay, because it has pop-up headlights, let's be real. However, the Miata is getting up there in age — there are many people driving 30-year-old Miatas around. With that age comes some issues. 

The Miata is a relatively reliable sports car, but there are some common issues that owners often complain about online — and some of them are easier to fix than others. Here are some of the most common complaints from Miata owners and some of the possible solutions.

A quick look on Reddit comes up with an endless stream of forums in Miata subreddits discussing the frequency at which batteries — even new ones — keep dying. Sometimes, an owner would excitedly head over to their Miata for a weekend drive after leaving it sitting for a few weeks, and the battery would be completely dead — and by sometimes, I mean a lot of times. The issue is that many Miatas (even newer ones) suffer from "trickle drain," which means something inside of the car is draining the battery even when not running. This could be the radio, the air conditioning, or something else entirely — it varies by car, and there aren't any confirmed universal sources. 

The most common solution is a trickle charge. This handy device ensures your car has power and is ready to use at all times. It's meant to slowly supply a battery with power over a longer period of time, making it particularly useful for cars that aren't driven daily. 

Miata owners are often on forums discussing electrical issues with their cars, often caused by dirty or loose electric grounds — a common issue with the Miata. An electric ground is a wire that connects a battery to various components of the car that require electricity to function. This includes things like lights and sensors. Bad wiring and dirty electric grounds do more than just leave certain elements of your car without power — they can also contribute to the aforementioned battery drain issues. 

The solution? Find all the grounds in your Miata and clean them. There's some debate as to where all of the grounds are located on each year Miata, so check the owner's manual if you still have it. Then, use a small wire brush to clean them all. After that, apply tune-up grease directly on them. This can really make a difference in a lot of older cars.

The internet is full of Miata owners expressing concern over the extremely loud sound of their car's gears, especially when decelerating or downshifting. Said one frustrated Miata owner on Reddit: "This is a hell hole of people with the same problem and no one knows what's going on. I am part of that people. Mine only does it in second and third gear, in the 3.5k -2.8k rpm range but not all the time. At odd times it does it while accelerating but normally it's decelerating without brakes." 

The worst part about the loud gear sound in many older Miatas is that there doesn't seem to be a worldwide solution. Miata owners have expressed frustration with the gear sound still happening after changing the exhaust, changing the fluids, changing the gearbox, checking heat shields, and aligning the powerplant frame. On the bright side, this loud grinding sound luckily doesn't cause any harm to your car in most cases. But you'll have to learn to live with the sound in a lot of older Miatas.

AC issues are so common with Miatas that it's almost comical. It's almost shocking if a Miata actually has cool air to blast at you while driving. The reason that Miatas have bad ACs is usually due to refrigerant leaks (but there are many reasons an AC may not have cold air). If there is not enough refrigerant, you'll possibly hear a hissing sound when you turn on the AC. It can be hard to pinpoint why your Miata is leaking refrigerant, but some Miata owners have accused the condenser, which is easily damaged. Another possible cause of the leak is dried-out seals. 

It's recommended to get your car checked out by a professional if you suspect a refrigerant leak. As refrigerant leaks, it can start to corrode parts of your car, overheat the compressor, and permanently damage the AC. Owners of the newer Miatas have also expressed concern about their AC leaking near the compressor housing, leading to expensive repairs. Hey, at least the Miata is a convertible.