OK update......the aircon being off does not sort the problem afterall as it did it with just the heater on the other night. It was rattling like a bag of old bolts at 6000-7500 rpm so much that I had to nurse it back home and this was also after only approx 5 miles of journey (so the long journey aspect of my original post is also out of the window).

If Redex (injector cleaner is added) this seems to reduce the problem considerably (possible lunbrication I am not sure?), however as soon as straightforward petrol is added the problem is horrific. I filled up with BP 95RON in case anyone asks. It had been running fine for about a week, even after quite a few red line drives up to the other night.

To revist the start of this post, does anyone think this is actually the OMP being the problem?

Would running a tank of premix possibly answer this, in that if it goes away it is most definitely the OMP?

 

What's your oil consumption?
if it is withing 1lt\3000km then i wouldn't worry about the OMP.

How's your catalyzer?

 

I will check the exact mileage when I get home tonight, however roughly I guess it would be using about 2 litres of oil in the last 4,000 miles.

Cat is brand new

 

Try premixing, it could be worth it. 250gr.
Your engine has indeed got a low compression so your problems may be engine related and made worse by other auxiliary items such as the catalyzer or coils, fuel pump etc (i don't recall your service history, sorry).

Start saving for a new engine and patiently wait! I think that I pm'd you about engines etc some time ago... did I?

 

BSE - yes you did post a msg about engine issues, however since then I have run cleaner through the engine and injectors and it would be interesting to see the compression figures again.

I do think that whenever you own an RX8 it is wise to have a 'spare engine' fund just in case, however mine really does not seem that far down the line yet!! (I hope anyway - see below).

I do have some important information though which is may be good and bad news. I took the car out last night and it really was struggling so today I went straight down to a local performance bike racing shop and picked up some Motul 710 fully synthetic 2 stroke.

I mixed a fairly good measure about 100:1 ratio and added my normal fuel. Guess what......I have just really given the car some gas and redlined 10-15 times and it ran sweet as a nut and sounded brilliant (it has not sounded as good since I have owned it). There was not a hint of any rattle and the power was brilliant.

I was always on the fence with the whole premix issue, however this has definitely worked for me.

So, back to my original post, would we all agree that if it goes away with a premix it is more than likely the OMP failing or dodgy oil injectors?

I get no CEL codes so it is doubtful that the OMP has failed completely, which suggests either it cannot cope with high revs or that the oil injector lines are shot - Any comments people??

Whilst I am happy this has worked, I am also worried that some damage may have been done. The car has been like this since last August (6 months), whilst waiting for the dealers to actually agree to fix the problem. I hope that the internal damage is not too bad given the length of time the oil has not been properly injected.

This should have been fixed months ago ........sooo annoying!!

I will do some further testing to make sure it was not just a 'one off', however the results look promising. It would be nice to solve this problem once and for all

 

Well, running for a long time with a poorly lubricated engine can cause premature wear.

The high premix is a temporary solution and it may help with both poor lubrication and worn seals so it is all down to how much oil your car uses
1kg\3000km is a good average while city driving, if you're away from that mark then it may be the OMP.

Again, the OMP may be injecting less oil than needed for 2 reasons:
1) You're running on an old mazda flash (04-05 cars)
2) Your OMP shaft is worn.

If you're mechanically inclined remove the OMP and slightly loosen the bolt that regulates it. It should increase the injection rate. 1/6 of a turn should suffice.

This will also help you to use your engine for some time but keep in mind that a worn engine may lead to more problematic issues if you just wait for it to die.
If you want to rebuild your engine don't wait, you may regret it If you just want to put a new engine when yours fails.... That's another story!

There are some easy modifications that can be done to a new engine in order to increase its durability, some of them are still being discussed so i leave it up to you to search for the answers

Many engines failed before reaching 50.000kms here because of poorly set OMPs

 

For my own sanity after reading ~ 1 bazillion posts, I tried to summarize some of these in:

https://www.rx8club.com/series-i-tech-garage-22/my-sneaky-plan-extend-engine-life-series-i-190372/

 

No extended warranty here

 

Thought I should finally bring a conclusion to this as I forgot to last year and there is nothing more annoying than following a post with no conclusion from the author!!

The conclusion was that I ended up get the engine stripped down by a professional roatary mechanic and I was informed that one of the rotor tips was damaged, which most likely was accounting for the problems.

The premixing probably helped as it provided a better seal, however eventually it would have given up.

He rebuilt the engine last year and it has now run sweet ever since. currently at around 12,000 miles on rebuilt engine.