Mazda MX-5 NB: Common Issues & Buying Guide

The Enduring Appeal of the Mazda MX-5 Mk2 NB

The Mazda MX-5, particularly the second generation, known as the NB (produced between 1998 and 2005), remains a beloved icon in the sports car world. Its lightweight design, rear-wheel-drive configuration, and superb handling have cemented its place as a driver's car. However, like any vehicle that has been on the road for a couple of decades, the NB MX-5 is not without its potential quirks and common issues. For those considering purchasing one, or for current owners looking to keep their cherished roadster in top condition, understanding these common problems is crucial. This guide will delve into the typical issues encountered with the Mazda MX-5 Mk2 NB, offering insights and advice to help you navigate ownership.

Performance and Reliability: A Mixed Bag

The MX-5 NB generally scores well in reliability surveys. In 2002, it achieved a commendable 4-star rating for crash safety and ranked highly for reliability in various surveys. Mazda as a marque also consistently features well in warranty repair cost indices, indicating a generally lower average cost for repairs compared to many other manufacturers. However, this positive outlook is tempered by specific areas that owners and potential buyers should be aware of.

Engine and Drivetrain Concerns

While the Mazda MX-5 NB is known for its engaging drive, there are a few drivetrain and engine-related issues that have been reported:

• Clutch Judder: Some 2003 model year MX-5s have been noted to suffer from clutch judder. This is believed to be caused by a change in the transmission mounting method. The result is a less forgiving clutch engagement, requiring a sharper, more precise clutch operation. Drivers may find it difficult to 'drag' the clutch smoothly, necessitating a quicker release.
• Steel Core Plugs: A more concerning, albeit less common, issue involves the steel core plugs located in the engine block. These plugs can corrode over time, leading to coolant leaks. If left unchecked, this can result in overheating and potential engine damage. Regular checks of the coolant system and prompt attention to any signs of leaks are advised. Replacement of these plugs is a job that requires draining the cooling system and careful work to avoid damaging the block.
• Limited Slip Differential (LSD) Issues: More recently, reports have emerged regarding limited slip differentials (especially Fujitsu units on later Series II models) breaking up. This can occur due to various factors, including stress during MOT rolling road brake tests. Signs of a failing LSD include noise and potential damage to internal components. Owners are advised to drain the differential oil and inspect for any broken metal fragments. A complete replacement differential can be a significant expense, with costs upwards of £2,000. Modifying the final drive ratio by fitting a differential from another model is an option, but this will affect speedometer readings and overall performance characteristics.
• Slow 1.6 Engine: While the 1.8-litre engines, particularly the 6-speed Sport models, are widely praised, the 90PS 1.6-litre engine is often described as being underpowered for a sports car. If performance is a priority, seeking out a 1.8-litre model is recommended.

The Pervasive Threat of Rust

Rust is arguably the most significant concern for any used MX-5, and the Mk2 NB is no exception. While generally better protected than its Mk1 predecessor, rust can still attack vulnerable areas. Proactive inspection and maintenance are key to combating this corrosive enemy:

• Rear Wheelarches and Wings: These are prime areas for rust to develop. Carefully check the outer edges of the rear wings and the inner lips of the wheelarches. Small bubbles in the paint can indicate corrosion starting underneath.
• Sills: The sills, running along the base of the car's doors, are another common rust spot. Water and dirt can accumulate in the sills, leading to significant perforation. This is often exacerbated by blocked drain holes.
• Blocked Drain Holes: The convertible hoods have drain holes that can become blocked with leaves, dirt, and debris. When these drains are blocked, water from the hood can back up, fill the sills, and find its way into the cabin, leading to wet carpets. More critically, this trapped moisture significantly accelerates rust formation in the sills and around the rear wheel arches. A simple preventative measure is to regularly clear these drain holes, perhaps with a wooden kebab skewer, to allow water to escape freely. Many owners have found extensive rust damage in these areas, with repairs costing upwards of £1,400.
• Front Crossmember (Facelift Models): For facelift models from Spring 2001 onwards, a deformable front crossmember was introduced. This component was designed with a laminated structure that unfortunately creates a perfect environment for rust to develop, potentially compromising structural integrity. Due to its location and complexity, replacement is a difficult and expensive undertaking. Thorough inspection of this area is vital before purchasing a facelift NB.

Other Potential Issues to Watch For

Beyond the major concerns, a few other points are worth noting:

• Hood Catches: The hood catches, which secure the soft-top, can be prone to wear or damage. Replacing these can be surprisingly costly, with trade prices around £187, plus fitting.
• Tyre Speed Ratings: When importing Japanese models (Eunos Roadsters), it's essential to check the tyres. Japan has a lower national speed limit, and tyres fitted may not be suitable for higher speeds encountered in the UK. Ensure all tyres have appropriate speed ratings.
• Ex-JDM Imports: Be cautious of uncertificated Eunos Roadsters imported after May 1998. These may not have been legally registered, and some could be 'clones' built from various parts. Ensure all import documentation is in order.
• Hard Driving and Servicing: As sports cars, many MX-5s will have been driven enthusiastically. Furthermore, some may have been treated as 'fashion accessories' and not maintained to the highest standard. Always look for evidence of regular servicing and a well-cared-for history.
• Remote Key Fob Reprogramming: If you're buying a car with a remote central locking system, ensure the key fobs are working. Reprogramming them can be a straightforward process, with guides available online, but it's a small detail that can be a nuisance if not functioning.

Recalls

While the NB is generally well-built, there have been a couple of recalls:

• Throttle Pedal Interference: A recall in December 2000 affected 135 Jasper Conran Limited Edition MX-5s. The driver's floor mat could interfere with the throttle pedal, potentially causing it to stick open. The solution involved replacing the mat with a modified version.
• Front Foglight Socket Holder: In December 2003, a recall was issued for a large number of Mazda models, including the MX-5. Repeated thermal expansion and contraction could cause the front foglight socket holder to detach, allowing the bulb to come into contact with the car's bodywork. A spring was fitted to the rear of the foglights to rectify this.

The Rarest MX-5 in the UK

For enthusiasts keeping an eye on the numbers, the silver Mk2 MX-5 holds the title of the rarest variant on UK roads, with only 58 licensed. While not a common issue, this rarity might be of interest to collectors or those looking for a unique example.

Conclusion

The Mazda MX-5 Mk2 NB offers a fantastic driving experience and remains an affordable entry into the world of open-top motoring. While it has its share of common issues, particularly concerning rust and some specific mechanical components, these are largely manageable with diligent inspection and regular maintenance. By being aware of these potential pitfalls and thoroughly checking any car you consider buying, you can significantly increase your chances of finding a well-maintained NB that will provide years of enjoyable motoring. The MX-5 NB is a testament to Mazda's engineering, and with a little care, it continues to be a truly rewarding car to own and drive.

Frequently Asked Questions (FAQs)

Q1: What is the most common problem with a Mazda MX-5 Mk2 NB?
Rust, particularly in the sills and rear wheel arches, is the most common and potentially serious issue. Blocked drain holes exacerbate this problem.

Q2: Are all Mazda MX-5 Mk2 NB models prone to rust?
While all older cars can suffer from rust, the Mk2 NB is more susceptible in specific areas like the sills, rear wheel arches, and the front crossmember on facelift models. Regular checks and preventative maintenance are key.

Q3: Is the 1.6 engine too slow for the MX-5 Mk2 NB?
The 90PS 1.6-litre engine is generally considered underpowered for a sports car. The 1.8-litre engine, especially in the 6-speed Sport variant, offers a much more engaging performance.

Q4: How can I prevent rust on my MX-5 Mk2 NB?
Regularly clear the drain holes in the soft-top and sills, keep the car clean, especially in winter, and consider applying an underbody rustproofing treatment. Inspect vulnerable areas frequently.

Q5: What should I look for when buying a used Mazda MX-5 Mk2 NB?
Thoroughly inspect for rust (sills, arches, chassis), check the condition of the soft-top and its catches, listen for any noises from the engine and differential, and review the service history for evidence of regular maintenance.

If you want to read more articles similar to Mazda MX-5 NB: Common Issues & Buying Guide, you can visit the Automotive category.