rGSkieS

Hi there guys I am new to the forum but I have a problem and hopefully you all can point me in the right direction. Been searching for about 2 days on the forums for an answer but it just doesn't seem anyone has had this issue or they resolved it but didn't really say how. A bit of background info on the vehicle, it's an '04 RX8, Auto, 62k miles, plugs and coils replaced shortly after I bought it and have only put 7k miles on it since then, the engine was replaced in 2008 and when I bought it the car had about 1,200 miles on the new motor (assuming it was just a to and from work car or weekend driver). On last Saturday I went out to start up the car and the battery was dead (the previous battery was 3 years old so probably time for a better one anyway), so I decided to wait until monday to pick up a new one (no sense buying a 180$ battery on saturday when I can get it for $40 2 days later). Hooked up the new battery things went smoothish with that, but this is another story, on tuesday I was on my way home when the car started to drop RPM's down to 1k as I was going about 65mph, then it would sputter out and try to die. Pulled over and the car ran normal for a minute, then the CEL came on and started flashing and RPM's dropped again from 1k to 100 and tried to die twice. The temps were normal, no steam from the coolant, been running it like normal (for an 8 that is), keep up with general maintenance (oil change at 2800miles, add oil at every other fill up as needed, run 2oz. of 2cycle per tank of gas). Anyone have any idea why the RPM's would just drop like crazy, engine would sputter and die, from just changing out the battery? Just seems a bit odd, someone told me it could be a temp sensor being offset from the batter being disconnected for a couple of days and threw off the computer, but I would assume this would auto fix after driving it about 50 miles. Another thought is that it doesn't completely die when driving, it just seems to sputter and kick for a minute and drop rpm's, then goes back to normal. Just feel completely lost on this one.

Vlaze

iTrader: (14)

Sounds like you might be losing compression, and a new engine might be in order

Bigbacon

iTrader: (4)

Check your cat to make sure it isn't plugged up.

flashing CEL could be a misfire, might want to go to autozone or something and have them scan it.

If not, take it in and have them do a compression check and hopefully your engine isn't dying.

rGSkieS

Really hoping that the motor isn't losing compression to tell you the truth. Just seems odd though that was no issue prior to changing out the battery. (edit) Going to pick up a diagnostic tool today, once I pull the code and find out what it is and get it fixed I will update. Before I run off anyone got any other ideas?

kelvin2003

Hi there, i am having the exact problem as you are having. let me explain \ introduce the experiences from my 8. the RPM swing between 1k~200 when you are idle\ free gear but the car is running without throttle. i had the problem after i have changed the battery. i found a suspection over some blog and they said you may try KAM and reset the fuel trims. i have tried the KAM and it just make it a littble bit better and it goes worst when you drive a little big longer.( i have changed the coil also)

what i am going to do is , an ECU reset and then KAM. here is the link for KAM and NVRAM

http://www.rx8blog.com/how-to-reset-ecu-on-mazda-rx8/

tell me your result too when you had the solution , thank you

zoom44

coils.

kelvin2003

do u mean changing all 4 coils will fix the problem ?

rGSkieS

Misfire, Cylinder #2 replace plugs and it's fixed until the next thing comes up. [Edit] Running lean now, going to finish up replacing plugs and wires. Got all the error codes though, will keep posting as things get done. Probably be Saturday night when I finish up.

kelvin2003

i am going to mazda service center by next monday. hopefully your log might help the technician to fix my car in shorter time

nuke0907

iTrader: (2)

i was having the same problems before my motor blew. i finally got it working but i honestly don't know what helped fix it. it still wasn't running perfectly though. then i finally really knew it when i lost almost all compression on rotor #2.

rGSkieS

Just got the parts in today, wires & 8 plugs (L & T). Going to start working on it tomorrow most likely, to much to do after work tonight. Got a new code last night though, "Misfire multiple cylinders" and "Running lean", should stil be plugs/wires to fix, the other odd thing i noticed was that it went from hot exhaust to cool, so its possible the O2 sensor is out. Will keep updating as I keep finding more things wrong and get them fixed. Unless its the motor or the cat, I don't want to be charged 20x cost just to do something I can do myself...

kelvin2003

have you ever try that when you rev your RPM to 2k and hold the throttle , RPM will drops to 1k plus and you may heard that your exhaust sound like " poo . poo ."?

rGSkieS

Just changed the plugs and wires out. Still a no go. Lost all power while I was driving it to check to see if problem was fixed. My guess so far is lost compression. Will keep posting as I get more details

rGSkieS

Yea, the popping sound? That's pretty normal from the exhaust. Nothing to worry about there.

rGSkieS

Well, I guess Vlaze was correct. Checked and replaced everything I could, took it in to have compression checked, that was it. Currently waiting on mazda to approve warranty on the motor, the saddest part is that I have only had the car 7k miles... I would assume the previous owner didn't take care of it at all.

Vlaze

iTrader: (14)

Honestly, I wish I wasn't correct. Just that when you replaced coils n plugs when you got it and only have 7k on it, no way were they the problem. It might of been the CAT contributing but, with your symptoms of not going past 1k RPM it sounds like it was something internal in the engine .

rGSkieS

I was hoping that it was going to be something simple, but it turned out that the seals in the motor were bad so it was losing compression and power randomly. The warmer the car got, the worse it would be. Oh well though, had been hoping to find something else but at least I managed to get it done on warranty work