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It seems as this forum (and the cars thumbup) become more and more popular that the usual "what to look for when I buy" threads become more and more frequent. So How about a Wiki containing the information and/or links to the other sources of information on the owners club site etc. if we can't be bothered to type it out again. smile

I've started us off but often find I don't know as much as I like to think. So fill it in if you like it. Or let it drop down the list if you don't. smile

09/03/10 - added a couple of notes. SH.
30/03/11 - added a few notes/made a few amendments. Lazza.

Sites with useful info


Description Link
Model Specifications (Owners Club) http://www.mx5oc.co.uk/content/specifications.aspx
Technical area of US-based site with details on pretty much anything - bodywork, electrical and mechanical. http://www.miata.net/garage
Model-by-model guide to UK special editions http://ox.mx5oc.co.uk/guide_mx5.htm
Model-by-model guide to Japanese special editions http://ox.mx5oc.co.uk/guide_eunos.htm
How can I do a diagnostics check on my Mk1? http://www.mx5oc.co.uk/forum/forums/t/204.aspx
Where can I get a proper wheel alignment check done? http://www.alignmycar.co.uk/


Common faults


Part Description Related models
Brake Calipers Brake callipers are known to seize on. Re-con parts are readily available. (Note I've just rebuilt a set of fronts, cost to refurb aprx £60, for all parts plus fluid. cost of re-con 'exchange' calipers likely to be £150+. SH) Rears are a "weak point" - the handbrake linkage gathers crap and mud over time and can stick, good practice to give the linkage a clean and spray with oil when you have the back wheels off MK 1, 2 and 2.5 comes on with age
Corrosion MK1 and MK2 models are quite poor in this area. In fact, it's the biggest MX5 killer. Watch out for rear sill sections, rear wheel arches and front chassis rails near front subframe mounting. The Mk2 and 2.5's are much worse in regards to front chassis rails - http://www.pistonheads.com/gassing/topic.asp?h=0&a... Don't be fooled into thinking an import will be better in this area as most of these are now 10+ years old All MK1 and 2. Rust perforation in the sills has been known on 5 year old cars
Elec. Windows Slow Electric windows get slow and stick over time, if they still go up and down fully the runners just need dousing in silicone spray grease from halfords or white lithium grease. Benefit for lithium is it wouldn't cause electrical problems if any gets on the electrics, benefit of silicone is not causing any rubber to swell. MK1 and older MK2 models
Windows Stuck On older cars the electric windows can sometimes start stopping going fully down. This is normally due to the clip holding the cable breaking. This can be fixed with a ziptie pulling the cable out of the way. Link with video here: http://forum.miata.net/vb/showthread.php?t=479201&... MK1 and MK2
Oil Leaks The o-ring on the CAS sensor on the back on the cylinder head can perish and start to leak. On 1.8 cars the oil will drip onto the coolant feed pipes for the heater matrix, eventually making them burst. Also the Cam-Cover-Gasket can start to weep oil, usually if not replaced when doing the cambelt. both are DIY jobs to replace with a bit of care. How-to guide: http://www.mx5oc.co.uk/forum/forums/p/308/494.aspx... MK1
Clutch Slave Cylinder The slave cylinder can sometimes fail and the clutch pedal will sink to the floor. A replacement unit can be had for around £30 and can be fitted in around half an hour. How to guide here: http://www.mx5oc.co.uk/forum/forums/p/200/361.aspx... Mk1 and Mk2
Wet boot Often caused by a perished rain rail which is the plastic channel that sandwiches the lower edge of the hood and guides water to the drain holes. Replacements can either be fabricated at home or bought from specialist websites. Fitting takes around half an hour Mk1
Water in sills Drain holes can become blocked, trapping water inside the sills. 5 minutes spent clearing the drains with a wire coathanger should fix it Mk1 and Mk2
Transmission tunnel gets warm This can get quite noticeable and can sometimes be remedied by changing the rubber turret boot that sits under the centre console. Over time these can perish and allow heat from the drivetrain into the cabin. Simple and cheap to fix. Mk1 and Mk2
Noisey tappets There is often noticeable tappet noise when starting up. Perfectly nomal for this to last a few minutes, but investigate further if it persists. An oil change is often all that's needed, although it could indicate worn or damaged HLAs. (Note - after multiple oil changes with semi-synthetic I was still getting HLA noise when hot. Changed to Mobil 1 fully synthetic and problem has completely disappeared - this is on a higher mileage Mk1 1.8. SH) Mk1
no tickover when warming up Change the green temp sensor at the rear of the engine block Mk1
Wing mirrors falling off Dismantle and replace bolt/nut that fixes mirror to the door. http://www.autolinkmx5.com/door-mirror-repair-bolt... Mk1
Idle droop Idle rate drops very low when in neutral, this can occur after disconnecting the battery. How-to reset guide: http://www.miata.net/garage/isc.html Mk1
Misfire Quite common for HT leads to go faulty particularly the shortest it seems(cheap option). Or it could be the coil pack. (More expensive) Mk1 / MK2
Steering Corroded power steering pipes, down on the rack all MK1 and MK2 models with power steering.
Hood Header rail catches can wear, losing their latching function. all MK1 and MK2
Crankshaft Key and keyway locating bottom cambelt pulley can wear. Check that pulley doesn't "shimmy" when engine is running. some 1.6 MK1 theoretically only on 1.8 if botched maintenance
Transmission Spigot and clutch-release bearings can develop a whine while clutch is engaged. all MK1 and MK2
Cambelt whine An overtightened timing belt can make a loud whine. all MK1 and MK2


Import or UK car?


Whether they were badged as an Mazda MX5, a Eunos Roadster or a Mazda Miata; all the cars rolled off the same production lines in Japan. The main differences relate to trim and options.

Japanese Imports


Pros Cons
Japanese shaken tests mean that general roadworthiness standards are often better than cars from the UK. Only relevant for a recently imported car Virtually no chance of getting a proper service history. Although this doesn't necessarily mean they haven't been serviced. If the car was still in Japan when it reached 100,000kms, check that there is a silver sticker at the front of the cam cover with a kilometre figure on it - this tells you when the cambelt was changed. Basically the car must be viewed on its own merits.
Japanese don't salt their roads, so a recent import might have less corrosion Insurance will cost more than a UK car.
Average annual mileages are usually lower in Japan. Any total-loss damage the car may have suffered in Japan will not show up on an HPI check.
Most cars had higher trim levels than their UK counterparts. Torsen LSDs are more common, as is air conditioning, power steering, etc. Harder to find a nice, clean "honest" car
There were some decently equipped limited editions such as the RS Ltd, The M2 cars, the S Spec, the V Spec.

UK cars


Pros Cons
Better chance of getting a full service history. Not necessarily a drawback but some cars had pretty meagre specifications and sometimes had steel wheels, no power steering, no air conditioning (useful for demisting in winter)
Lower insurance costs Later 1.6 MK1s were detuned to less than 90bhp rather than the usual 115bhp.


Which model?


Mk1 (1989 - 1998), also known as NA


The Mk1 is the original, and some say the best, of the MX-5s. Launched in 1989 it revived the spirit of popular British sports cars of the 1960s but thankfully combined this with a typically Japanese attention to detail. The result was a simple, light, two seater which aimed to offer an entertaining drive while being cheap to buy and maintain. The original 1.6l had 115bhp until 1994 when it was lowered to 89bhp to seperate it from the 1.8l. This had 131bhp until 1996 when it increased to 133bhp.

1.6 engined cars


Pros Cons
Lighter weight Underpowered
Some prefer the feel of the early 1.6's sweet revving nature compared to the more torquey 1.8 The earliest engines potentially suffered crankshaft problems - google short nose crankshaft for more details

1.8 engined cars


Pros Cons
The 1.8 offers a useful power increase over the 1.6 and the larger engine brings with it other benefits - better chassis bracing, an uprated diff, etc Fuel consumption suffers slightly


Mk2/2.5 (1998 [1999 for Miatas] - ????), also known as NB/NBFL


The Mk2 was updated in 1998 (or 1999 for Miatas). Fixed headlights replaced the Mk1 retractable ones, due to pedestrian safety regulations. Although there was an increase in power performance is very similar to the Mk1 as the Mk2 is heavier. The wheels, tyres and brakes were upgraded as well as the interior. Much more refined, with better quality interior. Boot far larger as spare wheel is now relocated. 1.8 has better low down torque than Mk1 unit, thanks to its variable length intake tracts. In 2001 the Mk2.5 was released, which had space for front fog lights, a revised interior, new seats, a slightly modified engine with VVT (resulting in 146bhp or 130bhp in the USA). The 1.6l engine had 110bhp.

1.6 engined cars


Pros Cons
Early (1998-2001) units more durable than 1.8 A bit underpowered
Please add your comments Running early 98-00 MK2 engines low on oil has been known to throw a rod


1.8 engine cars


Pros Cons
From 2001 engine now has VVT (Mk2.5) which pushed power up to 146bhp 1998-2001 1.8 can suffer from worn rings/high oil consumption, Running early 98-00 MK2 engines low on oil has been known to throw a rod
VVT engine very strong with extra crank bearing support and a decent flowing exhaust manifold Cars after 2003 had the Tochigi Super Fuji Diff which are prone to breakage


1.8 Sport


Pros Cons
Same engine as above but adds 6-speed 'box, LSD and creature comforts such as heated leather seats Heaviest MX-5
Please add your comments Please add your comments


Mk3/3.5 (2006 - present)

Please add a brief description of the Mk3/3.5

Please add an engine size


Pros Cons
More creature comforts, totally fresh chassis and engine design Only one part interchangeable with earlier MX5's - the side indicator
Please add your comments Please add your comments


General Issues


- The oil gauge for later NA and NB cars is a dummy gauge, and more use than a light. Early Mk1 1.6 have a real oil pressure gauge.
- Clean the drainage holes regularly. Lots will come up if you use search online for drainage holes. It's best to clean from the bottom as cleaning from the top can dislodge the pipes.
- Timing belt change at 60,000 miles.
- NB/MK2 cars have solid valve lifters so require periodic valve clearance maintenance.