mrhouseremix

Hello,
I have a problem with my 2006 year RX8 i've bought a week ago, i try to explain.

I got P2259 error as i took the car from the previous owner and bought the 3 solenoids part K5T49091, unmounted the whole air intake to clean (had some oil inside), changed the air filter and did a full service with replacement of the three solenoids.

Now the P2259 is solved but i've got P0410, the car runs well but seems it hesitates from 4000 RPMs till 6200 RPMs where i start to feel a strong power in plus in acceleration since 6200 RPMs.

I cleared the P0410 and seems not to appear again but i still feel that "jump" after 6200 RPMs when the car feels to accelerate way better and slighter.

Is that "jump" feeling normal?

Thank you

Loki

iTrader: (1)

P0410 shouldn't matter beyond the first 30 seconds of operation or so, that's the only time the air pump is active.

There shouldn't be any jump or stumble, the car should pull smooth to redline.

A couple of theories:
- one of the intake valves is sticky or slow to open (like if there was a slight vacuum leak in its line)
- ignition coils are worn out (very common ans serious with rx8's, but easily fixed/prevented)
- poor intake configuration

Is the car all stock? Can you test the intake valves operation by hand to verify smooth opening?

mrhouseremix

Thanks for the answer

Already ordered coils and plugs, just waiting them on Monday and I’ll mount.

The car is all stock.

Can you guide me on how to check the valves? Do you have maybe a pic of where to act?

thank you so much!

JoeBlow

https://www.rx8club.com/series-i-do-...valves-174009/

mrhouseremix

Videos of how it runs, both videos in full throttle and 2nd gear :



4th gear full throttle :
Link password : rx8


Let me know how it looks and if notice that weird “boost” after 6000-6200 RPMs.

Thanks

mrhouseremix

@Loki what do you think of the videos I posted above?

CaymanRotary

Seems like everything is operating well after 6k. Could possibly just be weak ignition components. That would be the first thing to try to see if there is a difference. Definitely also replace the spark plug wires. I believe a set of NGK's are under $30.

mrhouseremix

Yeah, after 6k RPMs i feel a "boost" and the car runs way slighter, tomorrow i'll get the coils and the plugs (NGK), will change both and try, if happens again i will replace the wires.

Other possible theories?

Thanks

CaymanRotary

Not quite yet. Sounds like its running good just doesnt have the power as you said. You'd be surprised what a difference new coils, plugs and wires can make.

mrhouseremix

I've checked the plugs few days ago when i did the full service and they were also a bad item number, they aren't T and L marked, just all four are the same

The previous owner always did service in official Mazda but here in the local dealer they are also Hyundai dealer, i think they use wrong products...

Thanks again!

CaymanRotary

In this case yes, this will cause problems. I wouldnt advise driving at that speed with improper plugs. Could potentially cause damage.

mrhouseremix

Yeah, tomorrow i'll change the plugs and coils, i'm not anymore gonna use it with wrong plugs

One more question, i did a full service using 10W40 Castrol GTX Ultraclean and gonna use it till 2 more weeks and then i'm gonna install the Sohn adapter and switch to Bardahl 15W50 Racing, it's a good idea? (i'm already premixing with 2T premium oil)

Thanks

CaymanRotary

That Castrol GTX 10w-40 is the only oil I use across 4 RX8's. I worry about running too much thicker in this engine. If you are doing a SOHN you could switch to a 5w-30 Castrol Edge full synthetic. Always use the Mazda oil filter though.

mrhouseremix

Here in Italy in summer the degrees are around 35-38 C° that's why i was thinking to switch to 15W50, do you think it's a bad idea?

Reading on few discussions many people say that isn't a problem running a thicker oil if the Sohn is installed... what do you think?

Brettus

iTrader: (2)

Classic symptoms of an inoperative SSV.
https://www.rx8club.com/series-i-tro...operly-265862/

do that test after shutting engine down and again after 5 mins after shutdown to check if vac tank is holding vacuum.

mrhouseremix

Gonna do that check tomorrow! Could you maybe upload a picture and circle where that place is located?

Thank you!! Gonna update you guys tomorrow!

CaymanRotary

I do know thicker oils are better for the bearings but not everything else. Full synthetic is far better for the engine as a whole and you can get the benefit from a thinner oil. This is only possible with a SOHN to allow for 2 stroke oil to be injected instead of the engine oil itself. You can run 15w-50 but I just believe it’s too thick even for a tropical environment. My personal opinion of course.

mrhouseremix

Thanks for your opinion! then, i think to keep the 10W40 (changed it few days ago)

CaymanRotary

Its a great oil choice. I run Castrol GTX 10w-40 in all the RX8's and they are all daily driven. I've not yet had any engine issues and all are producing good compression results between 7.5 bar, all the way up to 9.4 bar.

mrhouseremix

@Brettus Just checked the SSV, it operates when the engine turns on but doesn't operates when the engine turns off... do i have to unmount it and clean? I've just used some spray lubrificant and will check tomorrow if operates. What do you advice?

Brettus

iTrader: (2)

please clarify . Do you mean when engine is free revving it works per the video but then when you turn off the ignition it doesn't cycle ? Or after waiting 5 mins it doesn't cycle ?

mrhouseremix

@Brettus As i turn on the engine i see it moving but then turning off the ignition it doesn't move, no cycle... i didn't try to rev

Brettus

iTrader: (2)

Dunno why it would move as you turn on the engine (that normally doesn't happen ) so still confused as to what you are seeing.

If it moves when you free rev it but not after turning engine off and letting it sit for a while then switching ignition ...then it's a vacuum leak .

mrhouseremix

@Brettus Today i didn't have much time so i tried just to turn on and off the ignition and see if it moves (thought it had to move also just turning off the ignition).

Tomorrow i'm gonna make a full test and let you know... if there is a vacuum leak which are the possible positions where it leaks?

Thanks!

Brettus

iTrader: (2)

Could be the one way check valve leaking ..... the green/white one that sits above where the oil filter is. If it's not that it could be a leaking solenoid valve or the tank itself.