RX8 Engine Reliability

[noumenon]

How reliable is the lump in the RX8? Do they need rebuilding after a certain number of miles? Does the oil consumption result in reduced engine life if a previous owner wasn't careful and ran it low?

[19890]

Mines been fine I've done about 13 thousand enthusiastic miles and a couple of track days. The rebuild is only worth worrying about at 60-70 thousand miles and even then it might not actualy need doing(depends on type of usage /driving). If a previous owner hasn't bothered with servicing walk away you can't easily know what mischief has been caused

[Pui]

The RX8 is not the same as the RX7 and this whole "All rotary's will need a rebuild at 50/60/70k" is nothing but pub talk rumours. It won't/shouldn't need an impromptu rebuild through failure. This is going to sound rude but, 19890, for a supposed owner of a Prodrive RX8 and previous owner of an RX7 you could do with doing a bit of homework before you offer advice/scare others. *

I'm not saying that the RX8 engine is bulletproof, it's as liable to break down as any engine is, but as long as it's looked after in the correct manner (Full Mazda/Rotary specialist history, regular oil checks and top ups with the correct oil) then its no less of a risk than any other engine. Some have failed but, where the car has had a full Mazda history, Mazda have absorbed some, if not the whole, cost of a replacement engine.

More common is that owners have believed the engine has gone kaput after it loses power in the upper rev range but the usual problem is that the CAT has broken down. This is normally due to the engine flooding (something to be aware of) and the unburnt fuel damaging the cells in the CAT when the engine is started correctly.

• EDIT: The rebuild problem was from the days of the RX7 (turbo'd I think) where the oil system which keeps the rotor tips lubricated didn't do a good enough job and the tips wore down and required an engine rebuild to replace them. The rotor tips and the lube system was totally redesigned for the RX8

Edited by Pui on Thursday 19th March 13:39

[noumenon]

Sounds like they've made them as good as you'd expect from a normal piston engine.

They seem quite cheap for what you're getting. Is it just the fuel and oil comsumption (and hence visible costs everytime it empties your wallet) that put people off?

[Pui]

noumenon said:

Sounds like they've made them as good as you'd expect from a normal piston engine.

They seem quite cheap for what you're getting. Is it just the fuel and oil comsumption (and hence visible costs everytime it empties your wallet) that put people off?

Very cheap at the mo' and as such a bit of a performance bargain I was thinking about changing mine but can't find anything that similar age/performance/practicality/fun for the money (54reg/231hp/45,000 miles so, whats that, about £5k p/ex!)

Fuel consumption is a bit pants (19mpg around town, 24mpg motorway cruising) but the tank isn't huge so it doesn't cost a fortune to fill it. Plus it doesn't require high octane unleaded, the rotary gains no benefit from it, so you can fill it up on cheaper 95RON petrol.

If you look at a few other threads on here, the oil consumption isn't always that bad. There's, not necessarily high performance, Audi's (VAG engines) that use just as much oil and still be within Audi's tolerances. Buy a 5litre bottle in the house for topping up and keep a 1litre one in the boot, just in case. Castrol Magnatec 5w30-A1 is only about £30* from Halfords for a 5litre (which might last you most of the interval between services) so It's not a huge expense really .


EDIT * or places like the owners club often do group buys for oild and get very good discounts

Edited by Pui on Thursday 19th March 14:13

[Pui]

This is a quote from the RX8OC-uk. It was posted 16th Feb 2009 so it's current statements and not something Mazda said in a press release 2 days after the RX launch, lol.

Due to the recent concern ref` the longevity of the RX-8 engine I decided to carry out a little investigation - I have already spoken to a senior Mazda Technician about numbers of engine failure at his dealership and I was informed that there had been very few in the main being down to water leaks due to casting porosity.

Expanding on this I contacted a large Mazda dealership that has probably had more experience of the RX-8 than other Mazda dealers, the reply was that of several hundred RX-8 sales only a very small percentage had suffered engine failure which is generally the norm` for any engine of all variants with a small minority that cause problems, these figures for the RX-8 are not set in concrete but approx`:

1st failure at 36K miles which never had it`s oil changed!
2nd material failure of a Rotor.
Then 5 fail due to low compression and one had failed as it had been driven through a flood and cracked the engine.

An additional comment that usually Mazda will go out the way to pay some or all of the cost for failed engines depending on circumstances with no one having paid a full retail cost for a replacement engine to date shows a commitment by Mazda.

So there you have some of the facts from a knowledgable large dealership that deals with the car day to day which I think demonstrates that the RX-8 Rotary engine is as dependable as any!
Del.

It also seems that where an engine has failed it has failed at fairly low, 20-40,000, miles. AFAIK, no ones suffered failure of a replacement engine, but I'll edit this if i find something where I'm wrong.

Edited by Pui on Thursday 19th March 15:59

[300bhp/ton]

My biggest gripe with the RX8 is not the reliability but the horrendous big block style fuel economy combined with fairly low HP.

Apart from that I'm actually quite an RX8 fan and cheaper prices mean all the better!

[Pui]

300bhp/ton said:

My biggest gripe with the RX8 is not the reliability but the horrendous big block style fuel economy combined with fairly low HP.

Apart from that I'm actually quite an RX8 fan and cheaper prices mean all the better!

When I first got mine, the smile factor made me ignore it, then I went through a phase for a month or so where it did annoy me a bit but now I've just gotten used to it and, to be honest, it doesn't bother me. I think if I was doing 3-400 miles a week in it I might be a bit sick but as it is I don't and it doesn't lol.

It could do with a bit more power (not at the cost of economy though!) but it's one of those cars where it's very enjoyable at safe/just about legal speeds. If i was a regular track-day driver I'd probably be thinking along your lines, but as all of my driving is fairly run of the mill stuff I'd be more humped if I was driving something very powerful which was only being used at 40% of it's ability, if that makes sense.

It's one of those things now though that everyone (should) know about it so anyone who buys one then complains that the fuel economy is terrible/worse than they thought is just a bit daft. lol

[19890]

Don't get me wrong. I am a fan of the RX8. I'm only getting rid of it because the costs of the STI ( tax and insurance mainly) have gone completely ballistic since last I taxed and insured it last year before the increase in tax banding. I can't afford both, so the 8 has to find a new home. The new owner is coming over to pick it up on Sunday. I hope she enjoys it as much as I have over the last year

[jimmyV8]

Well not wanting to throw a spanner in the works and im sure I've just been unlucky but, Ive owned my RX-8 since Saturday and today ended up arriving at my local dealer on the back of a tow truck. To say im gutted is an understatement. Severe misfire is about best I can do to describe it and initial diagnostic checks indicate a electric problem (spark plug/coilpack). I just hope this isnt the start of things to come, car has been great until today.....

[RobDickinson]

Well mazda rate the rotor tips at 150,000 miles and thats the first thing (in normal operation) that should need the engine cracking open for, and that shouldnt cost that much compared with a couple of timing belt changes.


There are other issues, as above, the coil packs are stressed (4 plugs firing a lot more often, coil packs are pushed at 9500rpm).

Theres from what I can tell been a very low level of engine faliures at least comparable to decent piston engines which is acceptable and mazda are very good with these too.

[chuntington101]

one US race car builder is using these stright from Mazda. they only cost about $2500 i think and give you over 200bhp! thats not bad when you compear them to something like a K-Series or even a K20! lol

i think they would make a great engine for a Se7en type car!

Chris.

[wolves_wanderer]

jimmyV8 said:

Well not wanting to throw a spanner in the works and im sure I've just been unlucky but, Ive owned my RX-8 since Saturday and today ended up arriving at my local dealer on the back of a tow truck. To say im gutted is an understatement. Severe misfire is about best I can do to describe it and initial diagnostic checks indicate a electric problem (spark plug/coilpack). I just hope this isnt the start of things to come, car has been great until today.....

As Robdickinson said, sparks and coil packs are very highly stressed in the RX8, although unlucky to go straight away it can happen with any car. My Leon needed new coils about 2 weeks after purchase. Check www.mazdarotaryparts.co.uk for uprated coils.

[jimmyV8]

Thanks for that link could prove very useful. Im still waiting for the exact verdict on the car now, just a shame coil packs from the above posted website have a 2 week delivery time! Maybe worth remembering for the future though! Thanks

[wolves_wanderer]

jimmyV8 said:

Thanks for that link could prove very useful. Im still waiting for the exact verdict on the car now, just a shame coil packs from the above posted website have a 2 week delivery time! Maybe worth remembering for the future though! Thanks

Get one at stealer prices to get you mobile and then order a set of the uprated ones to prevent a recurrence.

[300bhp/ton]

chuntington101 said:

i think they would make a great engine for a Se7en type car!

Chris.

I wonder what the reason is that you don't see more kit cars using it though?

[chuntington101]

300bhp/ton said:

chuntington101 said:

i think they would make a great engine for a Se7en type car!

Chris.

I wonder what the reason is that you don't see more kit cars using it though?

i dont know that one mate. i wonder if it cos people are a little scared of them. there is a guy on the Kit car section of this forum with a RX7 trubo engine...Pretty impressive!!!

i dont know alot about the RX8 engines, but im sure i have seen people putting superchargers on them. now that could make for a lovely setup in a Se7en! Can anyone confirm the price of a RX8 engine from Mazda???

Chris..

Here is what one guys is doing! the stage 2 looks very good! http://www.mazdatrix.com/8forcedinduction.htm

Edited by chuntington101 on Friday 20th March 13:37

[vrod]

300bhp/ton said:

My biggest gripe with the RX8 is not the reliability but the horrendous big block style fuel economy combined with fairly low HP.

Apart from that I'm actually quite an RX8 fan and cheaper prices mean all the better!

When I bought mine I compared it to similar cars and performance. The nearest match is the VW Golf R32, its 2.9 V6 does 0-60 in about 6 and a half seconds, about 150 max, 230ish BHP and about 25 mpg. It is about right for its performance, its just most people think it should provide the ecconomy of a normal 1300cc - not a chance!
I think they are comparable to many jap performance cars when driven as such, what seems to let them down is they are very thirty in traffic and don't become significantly more ecconomical when driven carefully. Most other performance cars I've had with a V6, 5cyl quattro etc will allow for eco driving.

[300bhp/ton]

vrod said:

300bhp/ton said:

My biggest gripe with the RX8 is not the reliability but the horrendous big block style fuel economy combined with fairly low HP.

Apart from that I'm actually quite an RX8 fan and cheaper prices mean all the better!

When I bought mine I compared it to similar cars and performance. The nearest match is the VW Golf R32, its 2.9 V6 does 0-60 in about 6 and a half seconds, about 150 max, 230ish BHP and about 25 mpg. It is about right for its performance, its just most people think it should provide the ecconomy of a normal 1300cc - not a chance!
I think they are comparable to many jap performance cars when driven as such, what seems to let them down is they are very thirty in traffic and don't become significantly more ecconomical when driven carefully. Most other performance cars I've had with a V6, 5cyl quattro etc will allow for eco driving.

I think its more the fact that I have 2 V8 performance cars, both faster than an RX8 and both generally see better mpg too.

I do like the RX8, espcially the 4 seater ability of it, but a bit more speed for the mpg wouldn't be a bad thing IMO.

[RobDickinson]

300bhp/ton said:

chuntington101 said:

i think they would make a great engine for a Se7en type car!

Chris.

I wonder what the reason is that you don't see more kit cars using it though?

Theres a seven that used 12b then a 13b for ages, big issues keeping them quiet and cool enough, though it rocks.