Old Rotor

Please give us some more info...Year, Have you de-carboned the engine. What mods have you got? Whats the sound like?

DeViLbOi

iTrader: (1)

If your APV were stuck open you would notice a loss of power on the low end, bad idle, some power stumbling and your car would be slightly louder while performance after 6250 would normalize. If your APV were stuck closed the low end would be normal and on the high end you would notice a loss of power because it would be fuel rich. You might notice more backfires and your exhaust would smell really bad. I would expect a CEL for running rich though if you didn't get one for APV failure.

SauerKraut

Year is 2004, AT.
Sound is like I posted before; Exact same raspy sound everyone else in this thread is having.
I have not De-carboned the engine... guess it's time ot pick up a can of zoom-power or whatever it's called and give that a shot

DeViLbOi

iTrader: (1)

The RP Supercat will make your car raspy months after installation. Because of it's design the cat material starts to break down and it sounds like crap...that's just how it is. Oh yea...and don't waste your money on ZoomZoom cleaner ($30). Just go to your local autoparts store and pick up SeaFoam ($6). It is the same product without the Mazda logo.

chiggernut

Shiiiit yeah. I called up mazda, told em my problem (which is definitely your problems too) and dude tells me to bring it in for my new motor. Getting the recalled clutch pedal done while its in there.

BuBuBDunk

So what was the outcome?

SauerKraut

I have an exoticspeed on mine, but i doubt its the problem.... I put the exotic on because my car was making the sound with the oem cat. I bet its the typhoon intake somehow, lol. It seems most people posting here have aftermarket intakes

vglnte1

with this, is anyone noticing your fans coming on after the car is shut off? mine runs for like 10-15 minutes after I shut it off

DeViLbOi

iTrader: (1)

vglnte - You have a cooling problem. Check your coolant level and if it's ok my next guess would be a thermostat

ODDDOOD

iTrader: (3)

crazy world how this all works out...I remember trying to help you troubleshoot this problem when if first came up for you. Now I have the same thing...and boy is it irritating.

Based on this diagnosis, and this description sounds like my problem to a T, my APV is stuck closed. How does one go about cleaning/fixing the APV?

Has anybody else noticed that this happened after they overfilled the engine oil? I ask because while on a trip recently, I went to top off the oil and accidentally added too much. Since I wasn't at home, I couldn't drain a little off and had to run with this overfilled oil. It was during this trip that I started noticing the hesitation up top. I have never experienced this type of problem, except for my CAT...but I know that is not the problem because I've verified that the CAT is no more and is now a "race-pipe".

I'm trying to cover all the little things at the moment. I've cleaned the MAF, and I'll be installing the MSCAI this weekend in hopes that it might be the OEM intake or VFAD causing some issues. I guess there is also a potential that a vacuum line has actually come loose or even cracked and is keeping the valve from actuating?

Hopefully one of us will be able to break the code and get answers for everybody.

SauerKraut

THe guy before me constantly overfilled his engine oil... in fact there was a puddle of oil under the typhoon intake when I bought it from him... Perhaps I have something stuck open as well

My engine also gets REAL friggin loud when it's making the noise... up to 7500rpms right when it first starts up the sound seems normal enough... but when it makes the raspy noise at those same RPMS, it sounds like the car has no muffler.... Is something opening and venting to atmosphere?

DarkBrew

There is no substitute for methodical troubleshooting unless you have gobs of money and can afford to pay the dealer
Go through your intake system following this https://www.rx8club.com/showthread.p...&highlight=APV
Clean up your MAF and install a catch can if your oil filler neck still vents to the accordion tube.

Citrik

Did you ever meet with that Mazda rep and get an update on this issue?

ODDDOOD

iTrader: (3)

I think that (in bold) is important to note. If people are running aftermarket intakes (or K&N filters like me), than the MAF should be cleaned more often since the oil from the filters can leave an oily residue on the sensor and possibly gum up the rest of the intake system. This added to any "extra" oil dumped into the intake from the filler vent could cause some serious problems.

I ended up cleaning the MAF with the "special MAF" cleaner just to be safe. Reset the NVRAM (brake stomp method). My car felt a lot better and more powerful almost immediately. Once the trims were learned (a few drive cycles) and everything seems to be somewhat back to normal. Also, my catless exhaust smells a bit more like exhaust should smell (if that makes sense).

I think there is something going on with the car when it starts up and the fuel mixture is very rich and maybe this causes it to run with little to no problem, despite the MAF sensor being completely fouled.

As soon as the car gets up to temperature, the overly rich fuel mixture leans out and the sensor starts relaying bad information to the PCM for what is required in the fuel mixture to make it correct. The result is a very poor and inefficient detonation (pinging) because the air/fuel mixture is completely wrong since the MAF cannot get a good read on the actual stream of air.

Does this make sense to anyone else? I do field service for a living and develop and test theories all the time to try and find and fix problems...this is a new one for my car now.

ODDDOOD

iTrader: (3)

From Wikipedia: http://en.wikipedia.org/wiki/Mass_flow_sensor

Hot Wire MAF sensors are very prone to sensing wire element contamination. A condition referred to by many technicians as “growing hairs” happens when debris, dirt from cheap air filters and outside air stick to the sensing wire element, shielding it from the incoming air. This shielding effect prevents the MAF sensor from correctly measuring the air flow and mass causing severe air-fuel ratio control problems. An ECM not in control while at pre-load is a strong indication of a dirty MAF.



Sometimes I scare myself. Just doing a bit of homework after my post...I never actually knew how these things work and I don't even know what type we have in the RX8, but this fits.

Renesis05

It would seem that I have the same problem.

My details:
2005 6-speed sport
45,000 miles
K&N air filter
Magnecore plug wires
JIC Magic Ti catback exhaust

The problem 1st occurred around 25,000 miles. Just like the OP, a new set of coils/ plugs will seem to cure the problem for awhile. For me, new coils will buy me about 4000 miles before the problem comes back.

Earlier this year I gave up and took it to the dealer. They told me that both leading coils were "barely firing". After I replaced them myself the problem was fixed...for awhile.

The best way to bring out the problem is to drive on the highway at 70-80 mph for 15 minutes and then slow down and try to accelerate. It will barely idle, sounds terrible, and is down on power. Recently mine died while driving on the street. It didn't want to restart. After letting it sit for a minute it did.

I have some BHR coils coming soon and I will change the plugs as well. I'm not very optimistic that this is addressing the root cause though.

04auto

I am a brand new member and I need HELP!

Profile:
Model: '04 4 spd auto
Mileage: 71,400
56,600 mi. : K & N cold air intake installed
60,000 mi. : Ign. coils & wires replaced
Maintentance: All as recommended, sometimes w/ 5/30 oil - dealer over-filled oil on few occasions
Long-time symptom: Very strong sense of burning rubber after heavy driving - unexplained
Past history: misfire, some backfire (popping) and PostCAT code prior to new coil inst.
Current: Loss of power, growling/rumbling noise at high temps and/or under load & eventual stalling at start/stop. Code: large evap leak (cap)

Recently took long trip in N. Cal and had big problems in very hot weather and at altitude. Car made HUGE growling noise, no power and stalled after refueling at sea level and repeatedly during the trip - all in hot weather & mostly at altitude. Starting from a dead stop became an adventure. The growling sounds exactly like a leaking exhaust manifold on a piston engine - DEEP and LOUD RUMBLE! Ran smoother back home but growling resumed with temp. and driving under load, but the hot temps are gone and I can't reproduce for my mechanic.

My mechanic can't find anything yet. I am in rotary hell and have probably been there much longer than I know. For some time I had jerkey hesitation when starting cold, then on a Feb. '10 trip L.A. area had big power loss crossing mountains, after which we discovered faulty coils. The growling started quite some time after installation of the K&N intake. HELP!!!

ODDDOOD

iTrader: (3)

04Auto - There are a number of possible fixes here. I would recommend cleaning you MAF and resetting your fuel trims.

There is special MAF cleaner. It is very easy to pull out, two small screws and disconnect the electrical plug. Spray and let dry. I mention just above about the K&N Filters causing problems and explain why you should clean your MAF if you use an oil-filter.

Resetting your NVRAM is easy and can be accomplished by turning your ignition to the ON position, just before the car starts to turn over. Then you need to push the break pedal about 20 times in 8 seconds. You can search more about this procedure.

vglnte1

I made my own cold air intake, and I had the screen out. Figured it was worthless like my other hot rods. Ran great for months then started the same noise you all are having. I figured motor was toast. i out the intake all back to stock and took it in. all they said was 1 spark plug had some corrosion on it. i replaced all the plugs and just put the screen back in. Im back to my normal milage (was down about 70 miles to a tank) and it runs 100% again with no hic ups...

04auto

Thanks for the input. I have not been much of DIY-er since I owned a '64 Valiant back in the 90's. My mechanic whom I trust cleaned MAF thinks it may be CAT and advises taking to dealer, which has bad reputation. I can try resetting NVRAM - whaever that is. Also, I never had the 2008 MSP-16 re-flash done. Any more thoughts?

SauerKraut

Ok, so last night I pulled out my K&N filter and cleaned it. Took a look at the MAF, and it looked clean. Didnt have any cleaner(will be picking up some), just blew air over it. Reset NVRAM and the car ran beautifully this morning. Redlined it at least 15 times with no mention of this sound... then as I lined up my approach to the office, I decided to gun it one last time for it's triumphant finish. And it made the sound.
Going to try MAF cleaner, or maybe a new MAF sensor

DeViLbOi

iTrader: (1)

Prolly a dumb question...but what grade gas do you normally use?

SauerKraut

Never used anything below 93

04auto

I reset my NVRAM and drove 12 miles for a meeting in 1st & 2nd only between 4 - 7000 rpm, and and the noise was starting to return. Had I run it hard longer I'm pretty certain it would have been even louder. Still no power on the high end. Ambient temp was in 60's. I always run 91 gas (Calif) with either Chevron, Arco or Shell - occasionally Costco.

K&N intake coming off before I visit the Dealer. No other mods or decarbonization. I am new to the club & only re-flash my records show was waaaaay back via MSP - 04. Other than that, only back for recalls, the last being 4206 F - I show no other re-flashes done. I must be light years behind in these! What TSB should I refer to and what flash letter should I be telling them to do? Any other suggestions?

DeViLbOi

iTrader: (1)

My suggestion would be to remove the intake for a day before you schedule with the dealer and see if your problem goes away.