Mazda MX-5 MK1(Inc Eunos)

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Never lower an MX-5! Messing with the ride height or firming up the damping will only spoil the excellent ride.

Engine

Double overhead camshaft, 16 valve in-line four cylinder, 1597cc 114bhp, 1839cc 131bhp

Lubrication

Engine oil: every 5-7000 miles (whichever comes first) change the oil and filter. Use high quality 10W40 oil. Please dispose of the old oil in an environmentally friendly manner – local councils provide waste oil collection points. Sump capacity – including oil filter 3.8 litres.
Manual gearbox oil: MX-5 manual gearboxes are extremely robust and transmission oil only needs changing at 54,000-mile intervals. When this is due, drain the gearbox when the oil is warm and re-fill it with new lubricant to the same standard. Gears can frequently become stiff during cold weather, particularly before the car has heated up properly – upgrade to a quality synthetic oil to stop this.
Automatic transmissions: UK cars were not fitted with automatic transmissions but imported Japanese Eunos and American Miata versions were. This needs changing every 20-30,000 miles but it’s a complicated job and is best carried out by a specialist.
Rear axle oil: MX-5 rear differentials are extremely robust and oil only needs changing every 54,000 miles.
Running gear: drive shafts and propellor shafts are extremely robust and don’t need tending to. Suspension is equally reliable and arly needs attention unless there’s a broken spring involved.

Valve Clearances

Adjustment by shims. Inlet 0.21mm, outlet 0.31mm

Brakes

Every 5-7000 miles or annually (whichever comes first) examine the front and rear discs and pads. Pay particular attention to calipers as these can corrode and seize up with age. Many mkIs and even early mkIIs now need their pipes replaced due to age. Inspect the pipes thoroughly every 5-7000 miles or annually. Handbrakes are generally fine – any problems will usually be linked to sticking callipers. Be sure to check the cable for tensile strength. Drain and replace the brake fluid at 54,000-mile intervals and check it regularly.

Sundry Items

MkI UK cars are particularly prone to corrosion on the sills towards the rear wheelarches. This often begins on the inside of the sill and spreads outwards, so it’s difficult to spot. Take a look under the sills as regularly as possible for any signs of rot and immediately have them repaired by a bodywork specialist if they show up as it can become terminal. It’s not uncommon for the clutch slave cylinder to begin leaking. It’s easy to spot and a cheap and simple fix, so simply inspect the cylinder every time you change the oil. Rear tyres wear faster than the fronts because they’re doing all the work and may have to put up with the occasional tail slide. Pay extra attention to these as they can go quicker than you think. Imported models (Eunos and Miata) came with smaller batteries than UK cars. Many owners then fitted UK-spec batteries but didn’t bother to fit the correct clamp, which can damage the bodywork at the rear due to the battery rattling around. Electric window systems are flimsy and the wires can fray and snap – a slow rolling window often signifies that it’s on the way out. A complete and more effective system is available from mx5parts.co.uk for around £65. Due to their bulletproof nature, it’s not uncommon for MX-5’s to have covered big miles or have been used as daily drivers. As a result, the interiors can suffer from wear. Leather gear gaiters are particularly susceptible to tearing and often become tatty. Secondhand replacements are available from under £10. Seat belt stalks are another common wear point. They become scratched and the colour fades dramatically. Again, a pair of used replacement stalks can be sourced for under £20.

Cooling System

Every 5-7000 miles or annually (whichever comes first) check the level and quality of the radiator coolant (regular weekly/monthly level checks are also advisable depending on the use of the car). The MX-5 has a magnesium alloy head so it’s essential that the coolant is changed on schedule. There should be a 50:50 water/anti-freeze mix (printed on the container) and a top quality product is worthwhile. Drain and refresh the coolant completely every five years. A winter coolant check/refresh is advisable too, as many cars are not/may not have been used during the cold months.

Ignition

Firing order: 1-3-4-2 Spark plugs: Beru plugs recommended, though NGK Vpower items are equally good. Every 5-7000 miles or annually (whichever comes first) change the plugs. Timing checks are unnecessary on standard cars though there is an upgrade available for 1.8-litre engines that advances the timing to 14 degrees. This needs checking regularly – every 5-7000 miles or annually – as it is more sensitive than the standard set-up. Both standard and modified engines should have their timing belts changed every five years, regardless of mileage. Happily breakage rarely causes damage. Leads can break down over time. This can be hard to identify, so if in doubt replace the set.

Fuel System

Injectors are generally sound. The addition of a quality injector cleaner will help to keep the system running at optimum, however. Every 5-7000 miles or annually (whichever comes first) check the fuel filter. This doesn’t need replacing during every service but a new one should be fitted every 10-14,000 miles or two years. Pay extra attention to this if the car is recently acquired as it is frequently omitted by professional and DIY mechanics. The engine should idle at 8-900rpm after it has reachedtemperature. If it’s abnormally high or low then consider replacing the idle control valve.Every 5-7000 miles or annually (whichever comes first) change the air filter. Many cars are fitted with aftermarket
induction kits, which may not need replacing. K&N panel filters have a million mile warranty and don’t need replacing – clean them with the recommended apparatus every year, though. K&N 57i kits are equally robust (see top tips for further details, though).