RX-8 Owners Club UK

Morning All,

My name is Tommy and I've just purchased an '04 RX8 (reg MT54 UKX) that has been sat unused and uncovered for 7 years for a bargain at £100.
I am looking for some tips on starting it and what to check. So far I have checked the following items:
Fuel - Old fuel removed and new premixed fuel added to the tank and flushed through the system.
Spark Plugs - Removed and checked, all rusty and one cracked. Currently checking the coils by sparking one clean plug against a grounded part of the car for a spark. The leading and trailing plugs were swapped on one rotor so this could be why it wasn't running well.
Eng Oil - Level checked, low but not below min. marker
Coolant - Suspiciously low and currently checking for leaks in the lines. Unsure if the system had antifreeze in it when it was parked up.
Battery - Knackered and not charging so temporary replacement is in place.
Engine - Engine cranks when the key is turned but have not tried to start with the spark plugs in.
Rust - Very little patches on rear arches and boot. Quite rusty sills and underside.
If you want to see pictures of the car they can be found here: https://www.instagram.com/my_cheap_car_collection/ , no need to follow the account unless you're interested, its just where I keep my photos to save space on my phone.
The previous owner said it struggled to start up when cold so I assume this is an issue with ignition (makes sense with cracked and wrong order spark plugs I think).

Planning on checking coils and acquiring new spark plugs to see if it will run by istelf or with a tow start (and possibly replacing the coils and wires too if needed). This is my first project car so any advice on the next steps would be greatly appreciated. Thanks.

Sounds like quite a project.

On the subject of the coolant, the Max mark on the header tank is only half way up, checking while cold.

The "float" on the level sensor often gets waterlogged and sinks, giving a false low-level warning.

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I'd 1st see if it'll start as the next step as it sounds like it it cranks OK
something thats well worth doing as well is to clean the ESS ( crank speed on a normal engine) sensor as its collects all sorts of muck
then do the brake pedal stomp where you switch the ignition on and press the brake pedal 20 times about 1 second apart the oil pressure gauge needle should sweep to zero and back again to confirm its done its re calibration of the ESS sensor

also remove the MAF sensor and ensure that its clean and oil free
if its oily then remove the inlet to clean it all out

and doing a compression test should also be on the list you can get a reasonable idea if the engine is OK with a normal pressure tester if you remove the 1 way valve in the end and then watch the needle to check all the 'bounces' are to the same point

viewtopic.php?f=25&t=34703
viewtopic.php?f=25&t=36391

Then everything else here
viewforum.php?f=25

Followed by this viewforum.php?f=58,
for which you'll need this https://www.rx8ownersclub.co.uk/members ... Select.php

Hi Tommy & to the RX-8OC

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Hi and Tommy. It looks like warpcOil has provided useful links already. Good luck with your project.

Thank you to all that have replied and given advice, it has helped me greatly.
My I bought a replacement old spark plug for £5 to replace my cracked one and the car started and ran very well. It idled smoothly at around 750 RPM and I couldn't be happier.
However, hot starts are slow and lethargic which isn't a good sign...clutch is also slipping a lot and the car struggles to go into gear. Looks like the next step is going to be a rebuild after I do some more fiddling with the clutch pedal and its travel to see if it will engage properly.
I think I will be doing the rebuild in my farm workshop at home so any tips or advice would be greatly appreciated.
Thanks for the all the support so far!

definitely a compression test as the next step

Yes you're right I should do that first to confirm that the problem is with bad compression in the engine and not anything else. Thanks!

For anyone following and interested, front rotor had compression of 150 Psi!! But the rear rotor had 60 Psi... not so good. I am now halfway through the process of removing the engine from the car so I can take a look at the engine myself.

OK good luck

That sounds like a challenging project! How's it now?

For anyone still following and wanting an update:
Yesterday the engine came out and this morning I dismantled the engine to find the expected damage on the rear rotor, worn apex seals and damaged side seals. In the process now of securing parts so if anyone has a good place to get them then let me know! And any tips for other damage to look for or tips for putting it back together would be much appreciated.
The clutch is also completely ruined too.
For pictures see: https://www.instagram.com/my_cheap_car_collection/

https://www.mazdarotaryparts.com/mazda- ... -307-c.asp
Now https://www.racingbeateurope.com/

Just to add:

Having a Leading plug installed in a Trailing hole is a big no-no.

The Leading plugs are longer, and the Trailing holes shallower, and causes the plug to neck out into the aluminium.

Best case, is they weren't tighten up very much, so may only have galled slightly.
Worst case, they could have 'peened' the inside of the rotor housing inwards, causing a high spot that the apex seal has to bounce over (really not great) or a crack (also not great, but also happens anyway sometimes).

Not much you can do about it now mind you, but something to be aware of perhaps, and a warning to others who may stumble here.