04 Mazda Rx8 engine rebuild

Naz_st

I have an 04 Mazda rx8 that I bought second hand a few years ago, and it has the whole hot starting issue. I've replaced the plugs, coils, leads and battery, and the garage swapped out the starter with one from another rx8, all to no avail. So they said the engine was bad and needed replacing (they couldn't actually do a compression test as the tester unit was broken). Anyway, I wasn't going to pay the 6-9k they quoted for a new engine, and have decided to do the engine rebuild myself.

As this is a pretty big DIY job (and no, I'm not a mechanic, just a somewhat knowledgable enthusiast), I thought I'd see if anyone has done this before or had any advice / tips, etc? I have 2 different rebuild DVDs and am following RotaryResurrection's instructions for engine removal and teardown to shortblock. And before anyone suggests I'm mad for trying this: don't worry I understand the scale of the job, and I'm taking this on from the perspective of an interesting project - I've nothing to lose as the car is both unusable and worthless with a dud engine and I can't afford to pay for a new one. I also love the car and couldn't bear scrapping it as it's in otherwise great nick.

I think I have all the tools I'll need (engine hoist, stand, adapter, impact gun, sockets, etc) - though I don't have the specialist tools like a 2&1/8" socket for the clutch flywheel or the dowel pullers etc - anyone any ideas about where I can source these on a limited/negligable budget?

I made a start at the weekend and got up to the point of detaching the engine from the transmission before I got stuck (I think I didn't have the car jacked up high enough so couldn't get the clearence I needed to get at the top bolts). I ran out of time and had to leave it at that point... Next chance I get to have a look at it will be next weekend.

Also, I'm videoing / documenting the whole process if anyone is interested in seeing some pics (I'm doing this mainly so I'll have something to refer to when I'm putting it all back together again!)

Any help / advice appreciated. (but not the "it'll never work - you're mad" kind!)

Ferris

Fair play to you for giving it a go. I've no experience of the Rx8 but is it not easier to take the engine and gearbox out complete, especially considering you have a hoist. It will make the reinstall much easier as you wont have to line the engine up with the gearbox while it in the engine bay.

Otherwise you could hoist the engine anf release the gearbox and engine mounts and lift/lower the engine to gain access to the bellhousing.

Naz_st

Ferris wrote: »

Fair play to you for giving it a go. I've no experience of the Rx8 but is it not easier to take the engine and gearbox out complete, especially considering you have a hoist. It will make the reinstall much easier as you wont have to line the engine up with the gearbox while it in the engine bay.

Not sure - I'm just going by the instructions on engine removal on the rx8club site by a guy who seems to earn a living on rebuilding these engines and he says to do it the second way:

Otherwise you could hoist the engine anf release the gearbox and engine mounts and lift/lower the engine to gain access to the bellhousing.

Yeah, this is what I was trying to do but I think I just didn't/couldn't lower the engine far enough to get sufficient access to the top bolts between the trans and the engine - will be giving that another go next weekend. I guess I am also a little worried that his instructions won't work for a right-hand drive model (he's U.S. based), but we'll see...

The other problem I had was that the bolts between the exhaust manifold and the catalytic converter wouldn't come off (seem to be well rusted on). So I have to figure something out there...

Buford T Justice

Naz_st wrote: »

The other problem I had was that the bolts between the exhaust manifold and the catalytic converter wouldn't come off (seem to be well rusted on). So I have to figure something out there...

If you won't be tackling it until the weekend then steep them in plenty of penetrating fluid until then. Should shift them enough.

no1beemerfan

Did you not get a second opinion or bring the car to a specialist or someone that knows their rotaries or are you just taking the word of the garage you went to who couldn't even do a simple enough test as their machine wasn't working?
Sounds a bit mad to me but please post pics etc of your progress and keep us informed!

Naz_st

no1beemerfan wrote: »

Did you not get a second opinion or bring the car to a specialist or someone that knows their rotaries or are you just taking the word of the garage you went to who couldn't even do a simple enough test as their machine wasn't working?
Sounds a bit mad to me but please post pics etc of your progress and keep us informed!

Well, the engine is known for being sensitive and there have been a lot of rebuilds required at the 50k miles mark. Since I replaced the battery, coils, leads, plugs and tried a different starter, it seemed a fair assessment to me that the engine was bad (hot starting problem - cold starting was ok up until the very end).
Also, when I replaced the spark plugs I found out that the previous owner / mechanic had installed them incorrectly and had the plugs in the wrong places (each rotor has a leading and trailing plug which are different). I'm guessing 2+ years of driving it like this won't have done the already sensitive engine any favours.
Also the Mazda garage I took it to also said that there was only 1 compression test unit in the country for that car (I had to wait 8 weeks for it to "come in" from another mazda garage - only to find it was broken anyway...).
Figured it was a safe bet that the engine had a compression problem. Mind you, I didn't know there were "rotary experts" outside of the Mazda garage (who don't seem to be rotary experts at all btw)?

MetzgerMeister

Tell me about the 2nd starter you tried. All 2003 - mid 2005 rx8s came with the weak starter (part no. N3H1). From then on, an upgraded starter was put in from the factory (part no. N3Z1). Make sure it's the upgraded one that isn't working before you start this job. Also, a 70Ah battery is required along with the upgraded starter. Otherwise a weak battery won't be able to give the required output to operate the starter. Also, use RE7C-L plugs as your leading ones. They're better than the RE8C-L.

I had an RX8 for 3 years (2004 JDM) and had the starting issue for a year and a half until I eventually found out what the cause of it was. It started perfectly each time after that no matter what way I drove it. Starts/short drives/stops were never an issue for me after that.

Mazda garages are awful for trying to get people to buy stuff rather than give them a solution. I got a Mazda6 MPS a month ago and the window switch panel on the driver's door wouldn't operate the other windows at all. I rang Mazda and they said I needed a new switch panel.

After a bit of research online, it turned out that when the battery is disconnected/drained, this panel needs to be reprogrammed to operate the other windows. All I had to do was go to each door and hold the switches up for 2 seconds each. After that they were perfect. The Mazda stealership I went to didn't say a word about this.

Always try the cheapest/easiest option first

If you're looking for rotary experts, Eddie Doyle in Bray is the most well-known in the country. There's also a user on here rotor_dude who has been rebuilding engines for a long time.

As for the compression tester, there's more than 1 in the country. Mazda in Clonmel have one of their own that never left their garage. With that said though, a lot of places need to wait to get one from another dealer. IMHO, it's overkill to think that the engine has compression issues considering you didn't actually get a test done.

Naz_st

einheisserschre wrote: »

Tell me about the 2nd starter you tried. All 2003 - mid 2005 rx8s came with the weak starter (part no. N3H1). From then on, an upgraded starter was put in from the factory (part no. N3Z1). Make sure it's the upgraded one that isn't working before you start this job.

I don't know - it was the mazda garage that switched the starter. I assumed it was the stronger starter, as I guessed they knew of the weak starter motor issue. Also, it wouldn't even cold start with my starter at that stage, but it did with the other starter, so I assumed it was the stronger motor. It still wouldn't warm start the car though.

Also, a 70Ah battery is required along with the upgraded starter. Otherwise a weak battery won't be able to give the required output to operate the starter.

I had a new battery installed a few months ago alright.

Also, use RE7C-L plugs as your leading ones. They're better than the RE8C-L.

Good to know.

I had an RX8 for 3 years (2004 JDM) and had the starting issue for a year and a half until I eventually found out what the cause of it was. It started perfectly each time after that no matter what way I drove it. Starts/short drives/stops were never an issue for me after that.

What was the issue - starter motor/battery?

Mazda garages are awful for trying to get people to buy stuff rather than give them a solution.

Totally agree.

I got a Mazda6 MPS a month ago and the window switch panel on the driver's door wouldn't operate the other windows at all. I rang Mazda and they said I needed a new switch panel.

After a bit of research online, it turned out that when the battery is disconnected/drained, this panel needs to be reprogrammed to operate the other windows. All I had to do was go to each door and hold the switches up for 2 seconds each. After that they were perfect. The Mazda stealership I went to didn't say a word about this.

Always try the cheapest/easiest option first

Fair point - but I've essentially replaced the entire ignition system already! What else could it be?

If you're looking for rotary experts, Eddie Doyle in Bray is the most well-known in the country. There's also a user on here rotor_dude who has been rebuilding engines for a long time.

Great, many thanks for that.

As for the compression tester, there's more than 1 in the country. Mazda in Clonmel have one of their own that never left their garage. With that said though, a lot of places need to wait to get one from another dealer. IMHO, it's overkill to think that the engine has compression issues considering you didn't actually get a test done.

All good points. I didn't know there were any other test units available (the Mazda dealership said that Mazda Ireland only had one in the country and if any other tester was used they wouldn't accept the results or something).

The other thing is that even when I cold started it last time, the engine didn't sound good - was giving a weird gurgly, misfire-y, sound when idling so I kind of figured there was an engine issue. I also got a CEL at one point prior to having it towed to the dealer. Plus - is it possible to do a hot compression test if the engine won't start?

MetzgerMeister

Don't assume anything when it comes to something like that. If I were you, I'd check out the starter before a rebuild. N3Z1 is the number that should be on it.

The issue with mine was the starter. Not only was it the rubbish one but when I replaced it, I gave it to a friend of mine who owns an auto electrics company here. He stripped it for the craic and found that it was completely burned out inside.

Along with the starter I replaced the coils, leads (to Magnecor), battery and plugs (even though they were the 7 rating, just for peace of mind).

That misfire you're talking about could very well have been a bad ignition coil.

Hot compression test without starting the engine??? You could hold a hair-dryer to it for a while :pac: otherwise, no because not only do you need it hot, the engine has to be running in order to do the test.

If I were you I'd go this route first before doing a rebuild. Here's what you'll need at good prices:

70Ah battery (you said you already had)

Ignition Coils

Spark Plugs

Upgraded R3 Starter - This will still fit the 2003-2008 model

Magnecor Ignition Leads

If you don't want to spend money on a new starter, you could try scrapyards. For best bet, look for 2006 - 2008 models, otherwise you're gonna annoy yourself by trying to figure out if a certain 2005 is early or late 2005.

That MRP site also has engine rebuild kits if you're still going to go that route.

Naz_st

einheisserschre wrote: »

Don't assume anything when it comes to something like that. If I were you, I'd check out the starter before a rebuild. N3Z1 is the number that should be on it.

The issue with mine was the starter. Not only was it the rubbish one but when I replaced it, I gave it to a friend of mine who owns an auto electrics company here. He stripped it for the craic and found that it was completely burned out inside.

Along with the starter I replaced the coils, leads (to Magnecor), battery and plugs (even though they were the 7 rating, just for peace of mind).

That misfire you're talking about could very well have been a bad ignition coil.

Hot compression test without starting the engine??? You could hold a hair-dryer to it for a while :pac: otherwise, no because not only do you need it hot, the engine has to be running in order to do the test.

If I were you I'd go this route first before doing a rebuild. Here's what you'll need at good prices:

70Ah battery (you said you already had)

Ignition Coils

Spark Plugs

Upgraded R3 Starter - This will still fit the 2003-2008 model

Magnecor Ignition Leads

If you don't want to spend money on a new starter, you could try scrapyards. For best bet, look for 2006 - 2008 models, otherwise you're gonna annoy yourself by trying to figure out if a certain 2005 is early or late 2005.

That MRP site also has engine rebuild kits if you're still going to go that route.

Yeah, I already have the new coils, the magnecor leads, the new plugs and battery.
I suppose I could try a new starter (i'll be upgrading it as part of the engine rebuild anyway) but I guess I didn't see the point in doing that first when the starter motor the garage swapped in did start the car cold but not hot (I'm assuming it was a beefier one than my own original that wouldn't start it cold or hot at that stage). I assumed it was the higher-power starter motor as their diagnosis after that test was that it definitely needed a new engine, but the garage didn't seem that great so perhaps not...

MetzgerMeister

Well if you're getting a new starter anyway, at least try it on the engine the way it is first. It could save you a huge job!

Viper_JB

Naz_st wrote: »

The other problem I had was that the bolts between the exhaust manifold and the catalytic converter wouldn't come off (seem to be well rusted on). So I have to figure something out there...

Those bolts are welded in, they're not supposed to come off (but they can with a lot of persuasion best to leave them on though), just the nuts and springs on the other side then you gotta pull out the exhaust from either the back box or the manifold side to detatch.

Ferris

Naz_st wrote: »

The other problem I had was that the bolts between the exhaust manifold and the catalytic converter wouldn't come off (seem to be well rusted on). So I have to figure something out there...

Plus Gas, Rustola or GT80 is your friend here. I used rustola taking a manifold off and the downpipe off the manifold there recently and it made the job way easier. Soak the nuts a few times first though and use a socket with straight sides otherwise you'll round the nuts.

If it still won't budge you'll need a bit of heat.

muckwarrior

I had an occasional hot start problem on mine too. Upgraded the starter a year ago and she hasn't hesitated to start since. Whether you're set on changing the engine or not, have a look at the top of the starter and tell us the model code. If Mazda gave you the newer one you really should have noticed some difference. It spins roughly twice as fast as the old one.

Btw, if you're looking for some more local advice than rx8club try http://www.irishrotary.com/