MisterZJ

Dear Forum, I have an issue I would like someone to please chime in on how to resolve.

Today, Saturday, 4/3/2010, I spent ALL day doing some major mods to my 04 RX-8 6speed. They include the following:

*Drilled/Slotted rotors & ceramic pads all the way around.
*Plasma Coils ($645 upgrade)
*Iridium Plugs (old plugs were in awful shape)
*AEM Cold Air Intake
*Dual Resonated Mid-Pipe removing CAT.

Before all these mods, I was having the same rattling noise I am still experiencing, so I know what I did today didn't have anything to do with "creating" it; however, I was hoping it would eliminate it as there were noticable grounding "white spots" on every single coil I removed, some were severe. I was under the impression it could be misfiring. The noise is apparent from the driver's side, and ONLY is audible between 4-7k RPM's, and only under a load. You can rev the car all day long to redline, over and over, and you never once hear it. You have to have the car under a load and reach those RPM's.

This noise is now LOUDER due to the fact I now have no CAT. It completely destroys the performance sound i'm looking for as I also have a Greddy SP2 Cat-Back Exhaust. It was installed months ago.

Another peculiar issue is I appear to be experiencing power loss while this noise is audible. It isn't like a noise that is just there, but the car still performs. It is as if the noise is directly related to the power of the car. I thought initially it could be a mis-fire, which is why I upgraded the entire ignition system to the top of the line (as far as I thought) I already had 10mm plug wires, only 6-8 months old, so I didn't replace those.

On my first attempt cranking the car, it turned over and over and over and over with no fire. I stopped trying, checked the plug wires and coils to make sure I didn't miss one. Nope, didn't miss one. I tried it again with the pedal to the floor in fear I had flooded it the time before. Did that for about 10 seconds, then let off the gas pedal, and it finally started. It was a little rought initially; however, smoothed out.. I then took it for a test run, and at EVERY single stop, it would go dead. This issue; however, corrected itself after about 20 minutes of driving. I did pull the negative terminal off while doing all these upgrades as I wanted the computer to have a fresh reset after the upgraded coils and CAI were installed.

SO, this leaves me with the only problem being the "marbles in a blender" noise that is only audible under load and between 4-7k RPM's.

PLEASE HELP ME! WHAT IS THIS NOISE??

I'll do anything to get this eliminated! The car has 86k miles on it, so techincally the engine itself is still under the Mazda warranty until 100k. Could this problem be internal?

ANY advice is highly appreciated!! THANKS in advance.

Matt

2tone

iTrader: (3)

search for marbles in a can or miac...there are tons of threads on it. could be on your way to a new engine.

Mazurfer

Here, read this only if the noise seems to be coming from behind the glove box. If not, it's something else.
Most times MIAC can be solved with a restrictor in the heater hose.

https://www.rx8club.com/canada-forum-35/noo-my-09-has-marbles-can-noise-miac-191483/

I don't like where you said the noise was coming from though!

Old Rotor

If you have "MIAC"(Marbles In A Can) sound it is more of a Kegger getting hit by a lead hammer. This is preignition in a rotary engine. It is very damaging and needs immediate attention. It could be fixed by changing to a higher octane fuel or several other things could be causing this.

MisterZJ

Well, I think the best "description" of what I hear is it sounds like maybe a bolt is loose somewhere that is holding a purty heavy duty piece of metal in place, and that metal object is vibrating against another metal object. The strange part though, and reason why I don't think this is the case, is it doesn't happen ALL the time. For example, when the car is first started, no noise no matter what I do.. Even after the car has been running for some time, it doesn't do it every run. And when it does it, I can put the clutch in, rev to redline several times, then the noise vanishes, even with clutch out??

And just tonight while driving, I am experiencing signifiant "hesitation" issues as well. Acceleration is silky smooth; however, constant speed in any gear I get the feeling the car is "jerking". What could this be? The hesitation/jerking was not there before today's maintenance. I didn't change any of the iridium plugs' gap; however, they appeared to be exactly what the old ones were at. The plasma coils are one of the biggest upgrades I did, so surely that cannot be part of the culprit. ???

Any other ideas?

Thanks,

Mazurfer

Well..............if you did disconnect the battery, then the car needs to re-learn the fuel trims. Some people even stall out for a few drive cycles before it settles down. Did you disconnect the battery? I know you probably did, but check the plug wires again, that top leading one tends to come off. Make sure they all are snapped on. Maybe you need to clean the MAF?
In terms of the noise...............I really don't know. I have seen a thread where there was part of the SSV actuator making a noise. Maybe you can search on that and see. That noise would come from just left of the throttle body. I'll see if I can find that thread and link it back here.

Old Rotor

If it's preignition then it will show up when the engine is hot. After you are in slow stop and go driving your engine can easily get into the 200-210F even if it in the seventies outside. Your temp Gage will not move but it could be thirty or more degrees hotter then normal. If you are running reg and not prem gas you will get a funny rattling noise at first then if you push it harder you might get the MIAC(Marbles In A Can) sound. When plugs, coils, wires are in good shape then I would try a can of Seafoam($8 Walmart) and add it to a half or quarter tank of gas and ring it out give it a few revs to the redline after it warms up. Have you done a de-carbon cleaning on the engine? When I brought mine in with low compression they did a Zoom cleaning N/C. It says in the "TSB" it's covered till the 8yr-100K mile engine.

MisterZJ

Thanks for the replies. I had read something about the Seafoam stuff last night when I was searching the forums for answers. So, today, I realized I missed a vital piece of my AEM intake, apparently lol. There are two small screens that fit in the pipes, and upon first glance, I left them out thinking they would only hinder air flow, which is 1 of the 2 points of getting a CAI (cold air & lots of it). So, today, I re-inserted those, and cleaned the MAF sensor and had to add half a quart of oil (it had got a little low). That apparently helped out alot. I also went to Autozone and got some Lucas fuel additive as well as the Seafoam. I loaded both in the tank with 93 octane (which is all I ever run) and drove all the way to Atlanta (4 hour drive) and I didn't experience one issue at all!! I don't want to count my chickens, but I feel a combination of the missing screens (apparently stabilizes the air charge before it hits the MAF) and the fuel additives helped alot.

I finally got my CEL from my mid-pipe though lol.. But I knew it was coming

Who knows?

Also, on a side note, what "advantages" are there in purchasing the Cobb Accessport? I know it can turn off the CEL, but will it turn it off for ALL issues (like full on or full off) or just disable the second o2 sensor CEL? What are the other advantages??? HP/TQ increase??

Thanks,

Matt

Mazurfer

Well.......glad it was a simple as the screens. Yeah........most have to have at least one screen or air flow gets disrupted. That was a vital piece you didn't share with us! This was probably 99% of your issue.

I'm not an expert on the Cobb, but I know that you can turn off that o2 CEL and all other functions or ability to detect other CEls will still be there, so it's not an off/on situation for all CELs.
There are several advantages for the Cobb, especially if you get MM to tune it for you. I would suggest you go ahead and do some more searches on that and read up.