Buyers Guide

This is a guide for the potential RX-8 buyer which will highlight some of the points that should be of concern when viewing a likely specimen of the Series 1, and although there are minor differences, is also applicable to the later model R3 - the guide is based on member experience and additional information that has been collected from the Owners Club since the inception of the RX-8 in the UK in late 2003.

Firstly, it cannot be over emphasized that the RX-8 needs to be maintained correctly with particular attention paid to the oil level.
This is the heart blood of the engine, and if the supply is not correctly monitored and replenished then longevity of the engine may be suspect with the inevitable cost that will follow.
A 12 monthly interval of Mazda service history is no guarantee that oil levels have been correctly maintained by the present/previous owner, and as the RX-8 is designed to use oil in comparison to a piston engine, (which is designed not to use oil) then you see the need to be vigilant in establishing that the correct levels have been maintained throughout previous ownership before you part with your cash.
See Reliability

Secondly, it is now apparent that the ignition system should be in good order.
Again, it cannot be over emphasized just how important this is to the health of the Rotary engine. Basically, the ignition system consists of 4 coil packs (these are not listed as a service item) that feed the spark plugs. As a guide, at approximately 30,000 miles, the coils should be replaced as a failure of one or more coils may go unnoticed and will gradually deplete the efficiency of the engine seals and the health of the engine may suffer serious damage. It would be prudent to question the seller with reference to the age of the coils.

Spark plugs should be replaced as a service item every 37.5K miles or 3 years which ever comes first. The OE spark plug leads deteriorate with age, causing rust to form on the spark plug caps and should be replaced ideally at the same time as the coils. Magnecor and NGK leads being recognised as superior replacements.
Just as a foot note with regard to replacement of the coils, it has also become apparent that there are many cheap copies of the OE coils that have demonstrated a very short life span so it may be prudent to question the seller if the coils have been replaced, and from where they were purchased.
Genuine OE coils command a price of £200 - £250 per set, generally purchased from a reputable Rotary parts dealer. As an example of poor quality after market coils, they can be purchased on eBay for as little as £50+ per set. Whilst these may appear tempting at that price, remember you get what you pay for and just to repeat the previous comment, if the ignition coils are in any way faulty either through wear or poor quality replacements then this can result in un-burnt fuel washing lubricating oil from the Rotors which will lead to wear and loss of compression. In addition, the catalytic converter can suffer through excess fuel, damaging the precious metals in the core which will mean a replacement is required.
Either case will be expensive to correct.
Viewing a vehicle as a Private Sale
A Car Data check should be considered as your first move to establish the identity and past history of the car. It is quite a cheap and easy exercise to carry out, take a note of the VIN (Vehicle Identity Number) which should be visible through the RH corner of the windscreen, confirm that this tallies with the V5 registration document, and then check for the cars details with your chosen data check company. This check is not strictly necessary if buying from a dealer as they should have made the checks that all is in order before offering the car for sale.
  • Check the Insurance record (This is handy to know when viewing the car if it is actually insured to be on the road. NB. the disclaimer)
  • Check the Vehicle Tax status
  • Check the MOT History
  • Check the cars service record.
    The service interval is 12,500 miles or every 12 months from the date of registration. Use the record to establish if the car has been serviced by a Mazda or independent dealer.
    In addition, the bodywork inspection should have been carried out and book stamped accordingly, some dealers do this FOC with the service, some only do it if requested and then make a charge for it.
NB. RX-8`s registered before 1st July 2006 should have the usual service book complete with stamps for each service, after 1st July 2006 Digital Service Records were introduced the service book was dispensed with and service information was retained by Mazda UK but for each service a DSR printout should be given to the owner on completion of a service.

Questions to ask the seller:
  1. Although Mazda state that an oil grade of 5W-30 (not a full synthetic) should be used, through time and experience it has now become apparent mainly from Rotary engine re-builders that the use of a 10W-40 grade gives better protection for the engine bearings (Series 1). But it must be emphasised that the owner should draw their own conclusions and based on the current information available the owner should make their own decision which oil they should use, based on how they intend to use it. R3 cars do have a modified lubrication system and a recommendation to use a 5W - 30 grade, but again it is down to the owner which oil they choose to use. (Be aware that the Rotary engine is designed to use oil and Mazda claim a consumption of 0.25 litre per 1000 mile but consumption will vary according to driving style)
  2. Has the starter motor been replaced, a modified motor was fitted on early cars which by increasing the engine spin speed improved starting but only if the owner made a complaint if the engine seems to be sluggish when turned over then the battery may also be suspect.
  3. Has all recall work been completed which can depending on model year consisting of:
    Description : The dynamic damper heat insulator, which is installed on the manual transmission, may crack, causing abnormal noise. In the worst case, the insulator may become detached.
    Remedial Action : Recall the affected vehicles and replace the insulator with a modified one.
    Vehicle Id : JMZSE170000100090 to JMZSE170000101030

    Description : It is possible that cracks may occur in the ball joint socket of the lower suspension arm. Which under certain severe driving conditions, may cause the ball to separate from the ball joint socket, and a loss of steering may occur.
    Remedial Action : Recalled vehicles will be inspected to ascertain if the lower suspension arm fitted is of the affected type. If this is shown to be the case, the part will be changed for a quality assured item.
    Vehicle Id : JMZSE17**00100090 to JMZSE17**00113819JMZSE17**40100089 to JMZSE17**40113821

    Description : Safety Recall AF037A Drivers Airbag (Steering wheel)
    The reason for this recall is that on certain vehicles the Airbag may not provide adequate protection during a frontal impact due to inappropriate production and storage conditions, a replacement Airbag module is fitted.
    In total 9,170 RX-8`s affected VIN range: JMZ SE******100089 to 150684 ------ Production dates 28 July 2003 to 8 February 2008.

    The following item is not subject to a recall but may be an issue:
    Rust spots can appear on one or both sills in the area where the back door meets the front door at the closure point, the problem was due to the design of the back door seal which was modified in 2006, Mazda would deal with the problem by removing the rust and repainting the area and fitting a protective film – but only if the owner had raised a complaint about the problem.

    Special Service Campaign.
    This was not a recall as such but Mazda endeavoured to contact owners with a view to replacing badly corroded pipes as fitted to the engine oil coolers which are situated in the LH/RH front bumper openings, if sufficiently corroded the pipes could fracture and spill the contents of the engine oil supply.
    At the same time modified front plastic wheel arch liners were fitted to counteract the possibility of salty water spraying on to the oil cooler pipes, in addition rear wheel arches were inspected for the presence of any corrosion and dealt with accordingly the rear arches should have sealer applied to further protect the area.
Vehicle Recall:
February 2018 --- three vehicle recall's were issued by Mazda UK.
  1. There is a recall for the front lower arms to be replaced with new ones and new camber bolts this is for models made in 2003 & 2004
  2. Fuel pump seals replaced and possibly the fuel pump. (Series 1 models)
  3. Insulation of fuel lines. (Series 1 models)
Vehicle inspection:
From cold the engine should readily fire up without struggling. The battery may be suspect if not, at idle the engine tends to be a bit lumpy but should be super smooth and free revving at higher throttle openings with no rattles, any sign of a rattle from the exhaust may indicate a failed catalytic converter element. (aftermarket cat circa £300)
A slight backfiring or popping noise from the exhaust is usual and perfectly normal, it should be noted that it is important that the RX-8 engine be checked for easy starting when the engine is @ normal temperature, as an engine that struggles to start once warm may be a sign that there is a major problem. For further peace of mind then see the Hot Compression Test paragraph below.

A test drive should be smooth and fairly quiet on a stock exhaust with the engine pulling cleanly to maximum revs, a rev limit warning indicator in the form of a BEEP! will sound to let you know the engine is reaching that point, the brakes should be progressive and powerful with no sign of judder under braking The RX-8 is not commonly known for rattles but the odd car may have a few with the steering wheel and vacant passenger seat being known causes - the drivers seat can develop a creak but all of these are easily dealt with.

Self-check list
  • Check the oil level – in low temperatures the dip stick may be covered with a gooey mayonnaise type substance this is perfectly normal (it is basically emulsified oil) but it may take a couple of goes to get a true reading - get in the habit of checking the oil level when the engine is nice and hot as the build up of mayo` will be less.
  • Check the sump for corrosion as it is known weak point.
  • Check headlight levelling sensors are functioning correctly on the 230 BHP model as these are expensive to replace, the 190 BHP car has a manually adjusted system.
  • Check brake discs for corrosion a more caring owner will have painted them.
  • Check the alloy wheels around the hub centre bore for corrosion the wheels should be replaced if the car is under warranty.
  • Check tyres for wear and ideally they should be the same brand on all wheels the standard fitment on early cars is 225/45R18 Bridgestone REO40 and with the introduction of the RX-8 R3 225/40R19 Bridgestone REO50 were fitted - having odd tyres front to back (definitely not on the same axle) does not suit the excellent road handling that the RX-8 displays especially if some of the cheap tyres available have been fitted, tyres vary in price from £50 - £200 available in 3 categories:
    1. Cheap and nasty (Generally known as Ditchfinders) 2. Budget 3. Premium - the RX-8 is a finely balanced sports coupe, remember that when considering tyres.
  • Check for possible rust (not very common) in the area of the boot lid brake light aperture, sills from the rear wheel arches can be rusting.
  • Check the rear lights for internal misting of the lenses again this should be dealt with by the warranty but new seals will be needed if not.
  • Check if fitted the optional Mazda Strakes (on front wheel arch grills) and front crest (V on front bumper) for corrosion these items were plated Aluminium and as such were susceptible to corrosion, replacement polished stainless steel items are now available.
  • Check the condition of the oil cooler heat exchangers (radiators) and Air Condition heat exchanger in the front bumper for damage as they can get well bashed by road debris, if protective grills have been fitted by a caring owner more the better.
  • Check the front suspension anti roll bar drop links as they may be broken it will not be immediately noticeable on a test drive so check – it is not dangerous and they are not expensive to replace but be aware they can break, with the engine running the electric power steering should be light to turn from lock to lock with no hard to turn points.
  • Check the handbrake rubber gaitor as a section of the moulded gaitor that fills the handbrake aperture when the handbrake is in the on position can break off and leave a hole under the handbrake, a new modified handbrake should have been fitted under warranty but only if the owner at the time raised a complaint.
  • Check for wear on the drivers leather seat side bolster stitched seam and the plastic front seat backs as they can be damaged by the seat belts.
  • Check for full function of the excellent BOSE Radio/CD player as it forms an integral part of the fascia and as such is expensive to replace although an aftermarket kit is now available to enable the fitment of a standard DIN radio/CD player as a cheaper or preferred option.
Be aware!
When presenting an RX-8 for an MOT you should inform the tester that the car is equipped with an LSD as it has now become apparent that some MOT stations are not aware that the car is so equipped (although that information should be available when the cars details are entered into the system) and as such the usual brake test using rollers should not be carried out as damage can occur to the differential.
There is an option to carry out the brake test with a decelerometer which will not damage the differential.

Hot Compression Test
This is an instantaneous health check on the motor and ideally should be done by any seller selling privately prior to sale, or should be agreed to by any dealer. This test should be performed using a Rotary compression tester and you should see results arranged like this:
Rotor 1
7.4 kgf/cm2
7.5 kgf/cm2
7.4 kgf/cm2

Rotor 2
7.3 kgf/cm2
7.4 kgf/cm2
7.4 kgf/cm2

RPM: 250 rpm
Compression specification is below:
  • Standard: 830 kPa {8.5 kgf/cm2, 120 psi} [250 rpm]
  • Minimum: 680 kPa {6.9 kgf/cm2, 98.6 psi} [250 rpm]
  • Difference in chambers: Within 150 kPa {1.5 kgf/cm2, 21.8 psi}
  • Difference in rotors: Within 100 kPa {1.0 kgf/cm2, 14.5 psi}
If the engine cranking speed isn't 250 rpm then the figure can be corrected using the graph below and the people performing the compression test should be able to do this.


A compression test cannot guarantee the future life of the engine, but it should show you're not buying a car that has a defective one.

As more R3's are now appearing on the used market the requirement of a compression test is even more critical for an R3 than any S1, as the higher speed starter means that "the hot start test" won't reveal low compression issues. This also applies to S1's that have been fitted with either an "upgraded" or R3 starter.

Fitting an "upgraded starter" can either be as a temporary fix for low-compression (in order to sell the car on) or a conscientious owner has replaced a slow started with a faster unit to ensure good clean starts; therefore it's either very bad or very good news.

Few Mazda dealers have rotary compression test equipment these days, and only a subset of those know how to use them.
Many don't even know that you can't get meaningful results from a normal tester, no matter how much they may have paid for it.
If in doubt, seek the assistance of your nearest rotary specialist, preferably before purchase or at least very soon after trade purchase where you still have the opportunity to reject the car.

Update: 2017

The key to acquiring and owning an RX-8 is either;
- buy the best you can
- buy a car that is structurally sound, good bodywork etc, with a known engine problem and get the engine rebuilt - factoring both the purchase price and rebuild into the budget.

Unless you're buying from a trusted source then assume you're (at least) going to need to replace the ignition components, unless the car is very low mileage, plus anything else that may have worn-out in the years that the car's been on the road.

One disadvantage of the cost of the used cars coming down is that many have now gone through the hands of people that can't really afford to run them. At minimum this often results in them being fitted with budget (ditch-finder) tyres, throw-away cats and engine-killer coils, while skimping on servicing and general TLC. Buying a car with this history can add greatly to the cost of getting it back up to a reasonable standard, though it still might work, depending on the purchase price. It also helps of you can undertake some of the remedial work yourself - following the DIY threads to replace coils, brake pads etc.

It's also possible to pick-up complete bargains, where people assume that their car has terminal engine failure, when it's just something simple, or they've realised that they can't keep filling the tank with fuel and want rid.

You need to work-out your first year budget, to buy the car, undertake any work necessary, tax and insure, plus fuel @ less than 20 mpg. From this you'll know if you can even afford an 8 and what your options are.

To a potential new owner I make two strong recommendations, either;
- buy from a recognised rotary specialist, with a warranty
- take someone with you who knows the cars and knows what to look out for; what to walk away from, what to haggle over and what to not cloud your judgement.

Many established OC members are happy to do this, as will some specialists (though obviously they still can't provide a warranty)

Disclaimer. This guide is to assist potential owners of the RX-8. Any inaccuracies or misrepresentations are unintentional. The author or the RX8 owners club cannot be held liable or responsible for any actions or consequences that may result from reading this guide whether consequence is resultant directly or indirectly. In any doubt always consider the services of a reputable vehicle inspector, UK Mazda Dealer or reputable Rotary & RX-8 expert notwithstanding any further liability shall rest with 3rd parties and not the aforementioned disclaimed parties.