Hey everyone, i was wondering if someone can help me out.
My car is acting up, the symptoms are:

1- after driving for 30 minutes the power is almost gone (car is loud but doesn't have any pick up) and it sounds like there is rocks or marbles in the exhaust while accelerating.

2- While this is happening, if I turn my car off for a few minutes(revving it before shut off) it takes 5 minutes to get started again, it just keeps turning over and not catching.

last time this happened the engine light was on. I changed the catalytic converter some O2 censors, spark plugs and shutter valve, the problem went away for about a month and now its back. (with no engine light)

After recent events, I don't want to bring my car back to the dealer that did the work because, well...I think they or whoever worked on my car is incompetent, the amount of damage done to my poor 8 (smashed fender, some kind of quarter sized paint chips on rocker panel, bent the metal RX-8 plaque on the door step, the battery cover clips and the hood prop rod clip) and the number of times i had to go back to the same place for the same problem is too much.
Not to mention my car doesn't run the same after i got it back from them.

I am hoping this is a quick fix that i can do myself.

Any help is appreciated.

Thanks Everyone

 

Need more details.. kilometer-age?

Have you ever changed engine coolant? Have you monitored engine coolant temperature?

 

Its a 2004 GT with about 100k. I have kept it topped up but never gave it a flush. the temp has always stayed in the normal range.

I don't think its a coolant issue, every time this happens it sounds like there is something plugged up or muffled when i accelerate.

I changed the air filter 2 years ago but i don't think i drive it enough to need a new one.

 

im having the same problem as u man same year only difference is mine have 170k on it...im thinking about just rebuilding the whole engine and porting it

 

Symptoms sound like a bad Catalytic Converter.

 

I thought about that. I cant afford to do it yet. Any idea what the problem is? O2 censors? intake? there has to be a solution.

 

That's what i thought...replaced mine a month and a half ago

 

Have you cleaned the MAF sensor lately?

 

That depends...what is a MAF sencor?

 

It is located in the accordion intake tube. It has a wire harness connected to it. This will be a general explanation of the MAF. LINK
But really the lack of power your describing all sounds like a bad Cat. Or a bad fuel pump possibly.

 

Thanks, Ive never cleaned that censor before...or changed the fuel filter.

would any of these issues cause the car to behave this way all the time?

It seems to happen after driving for 30 minutes.

 

MAF can and certainly the fuel pump/filter. Though clogged fuel filters are really not that common.
More failing fuel pumps.

 

Thanks Easy, I'll look into it as soon as i can. I hope this works.

 

After donning rubber gloves and safety goggles
use your favorite electrical parts cleaner to
hose down the sensor wires and any other
things hanging off the working end of the MAF.

 

Sounds like a Cat thing to me as well, but you changed it.
U can also use brake cleaner to clean the MAF, very ez.

 

probably is your cat and fuel pump. your fuel pump goes and your car runs lean super heating cat causing it to fail prematurely.

also if your old cat went and the dealer didn't clean it out of your exhaust system it could be causing a blockage.

why are you paying for a cat when your are covered under the emissions warranty to 128 000?

 

Please do not use "Brake Clean" on the MAF. Get a specific Electromotive cleaner or a MAF cleaner.

 

Brake cleaner...

 

I didn't have to pay for it...it was the ONE thing Duffrin mazda didn't screw me on

 

[QUOTE=nate340;3533153]also if your old cat went and the dealer didn't clean it out of your exhaust system it could be causing a blockage.

What would they have to clean out? do i have to worry about the new cat?

Man, I think this is the last time i bring my 8 to that dealer

 

sometimes the cat shatters and you can hear all the bits rattling around inside the exhaust system and they can cause a blockage.

other times cats just melt into one big solid chunk and its not a issue. but if it sounds like something is rattling in your exhaust system and you feel that your exhaust note is muffled i feel it would be highly likely you have parts of your last cat still in you exhaust system.

 

Thanks Nate, That kinda helps...but now the rattling sound seems to have gone away. The muffled sound is still there. I was asking around and someone said if the fuel filter is blocked its always blocked. there wouldn't be an intermittent loss of power. This weekend i will finally have the time to get some electronic cleaner and deal with the censor.

Thanks everyone for all your suggestions. I will keep you posted

 

I had something similar happen to me last summer. I replaced the cat, spark plugs, spark plug wires, and ignition coils and the problem was fixed, seeing as how you've replaced all of those except the coils I would think that those could be causing the problem. After that I also got the upgraded starter which is important to do if you own an 04 cause our starters are really weak.

 

Run the car up to operating temps. Check the colour of the exhaust. Do you see black soot or blue smoke or white smoke? Now shut the car off. Pull the plugs out and check the colours/soot on the plugs. Google search what a proper running plug should look like. Black soot means running too rich, white chaulky stuff means running lean.

Start with this.

 

means your engine is dead... go see another mazda dealer and he will replace it.. under warranty... they are just milking you for now.. the reason for the loss of power is that compression is off on the engine.. thats why it sounds like a bag of rocks. make the problem seem alot more worse than it is and then get it replaced make sure you trash talk the other dealership you went to first to the new dealership they will be nicer to you. but im pretty sure the compression is off when you drive the metal expands and the pressure leaks out the sides.. new engine