RobiRX8

Does anyone have this in CA with 91 poor fuel? I experience knock under full throttle after 6000 RPM and again around 8500 RPM. Funny is I was couple of times to visit dealer and they are claiming that this "vibration" is normal. I am in Riverside area.

Besides that I don't have any real problem, only gas miledge is bad 200 miles for gas tank (14 gallons fill ups). Is possible that this is because 91 poor CA octane fuel with Ethanol aditives? Well if so how come Mazda can't deal with it. If someone know or have some feedback I will be happy to know.

rx8spiritR

i don't know about knocking. but i know my 1st gear can only take me to 25mph no matter how hard i step on my throttle, it'll keep rev up but the can won't go, no power, i'll take it back to dealer wednesday. but i've never pass 8000rpm, maybe i should try huh....**** bro we got the exact gas mileage, i have half tank now and it only give me 92.3 mile.

dknv

Stupid question, but Does a rotary engine knock? I reported this to my Mazda service person, when I had a power loss on an uphill drive, and he indicated it wouldn't have been knocking.

RobiRX8

Yes Rotary engine knocks as the same as in traditional engine there is combustion of fuel and air.

Jsuzuki

rx8spiritR: Was your low oil or low fuel light on? First gear is good to about 40mph and I can easily tap the rev limitter.

RobiRX8: What brand of fuel are you using? I have run with fuels that contained ethanol without issues. I stick with major brand fuels like Chevron or Mobil.

RobiRX8

I Use 91 octane 76 or Shell station. I am scheduled for service tomorrow so I will see.....Next step that I will try 100 octance performance fuel which is street legal but no ethanol. I would like to also see if it will improve my fuel consumption. What is yours?

Jsuzuki

I hover around 19 to 21 mpg depending on how long I'm stuck in bumper to bumper traffic. It's kinda wierd where my last 300 mile trip up to Vegas with sustained speeds of 90+ mph got me 19 mpg. My trip back at a more sedentary speeds for 70 to 80 mph got me 22 mpg.

I do not think high octane fuel will help you get better mileage. And even if it did, at $6 a gallon you would need to get three time better mileage to make it worthwile.

Have you gotten the latest PCM caliberation from Mazda for your 8? What you are experiencing almost sounds like my car before the flash.

What are you shift points? Are you keeping the engine speeds between 2.0k and 3.5k?

Do you regulary spool up to high engine speeds to clear out any deposits?

RobiRX8

I do have M Flash so that's why I am currious why there is not improvement. I did tap brake test and it worked so I believe it's correct flash.

I want mainly try high octane to get rid off knocks, but I hope they will fix it tomorrow at my service. Howevery I must say they are not that bright so I will see.

With this fuel consumption I drive very easy and my shifts are no more than at 4500 rpm. I don't even want to know what would be fuel consumption under full throttle.

Once I get rid off knocks I will be able to drive more agressively once a while.

Did they place sticker on your car once they did M flash, they did on my 8 but I looked at it and numbers are just made up. I don't trust them much.

I would be happy to have your fuel consumption....

rx8spiritR

do you have the M processed paperwork? and **** i use shell 91 which is the best in San Francisco. my oil? it never move when since i got this car, it stays solid above half, my fuel? it matters? i think i am a little bit over half tank. and yes after million times of driving it hard in 1st gear, 25 - 29 is the best i can do, i stay at 1st all the way until i heard the beep. so something's wrong right? i didn't notice anything when i got the car cuz i was so dumb that i baby it in evey shift and never driven it HARD! so now i'm pretty sure i'm fully brake in. and this **** is really pissing me off....

Jsuzuki

RobiRX8: Perhaps your sparkplugs are fouled? What you are experiencing is not normal... Did you get one of the mechanics to ride along so you can show him the problem? Your mileage is pretty low but there could be a number of reasons like long warmup times or long idle times. It seems that the 8 to consumes the same amount of fuel whether at speed or at a stop... Maybe you could attend one of the rotary club meets and see, hear, and feel what other 8s are doing while accelerating.

rx8spiritR: Forgot to ask, automatic or 6 speed transmission? If the 1st gear ratios on the automatic and 6 speed are similar, the 7k rpm redline will translate to about 30mph.

rx8spiritR

mt

Jsuzuki

Something is wrong with your car... Can't figure it out over the web. Time for a visit to the dealer it seems.

Edwin Clairmonte

My 2004 /5 rx8 knocks when you start it but you hear it louder in drive or reverse
it’s an automatic and has around 78,000 miles on it
can anyone give me and idea please
it’s a clucking / knocking sound
it sound like it comes from the lower right of the car
thanking you guys in advance
do hope it’s not a rebuild

Loki

iTrader: (1)

Can you start your own thread in the new members section and possibly post a video of the situation? 'knocking' could be many things, from a loose heatshield to a spun engine bearing.