Pin8

iTrader: (1)

Hi all,

This may be a little long but I think it's better, that way you guys have a better understanding of what's wrong with my car.


I bought my car about a year ago. The previous owners cared for the car very well, regular maintenance, garaged, 91 octane etc... When I bought the car it ran great. I decided to get the Mazda Zoom cleaner and clean the engine. Sometime after that, I was accelerating in second and at 6000 rpm, it felt as if I lifted my foot off the accelerator for 2 or three seconds ( I hadn't) it was fine after that but there was a faint fluttering sound and it didn't go as well as it should have for the rest of the trip. The CEL was illuminated for a few trips after that but then it went away. I didn't have a reader at that time so I didn't get the code.

Some time after that I went for a long trip. At the end of it as I was accelerating I heard a very loud knocking sound (marbles, popcorn etc..) and experienced extreme loss of power. For the rest of that trip I heard pinging and experienced lack of power. I did some research and figured it might be the coils so I changed them, but that didn't do anything. When I would drive for longer than a few minutes, the car would knock loudly and would not accelerate nearly as fast as it should. As the car would get higher in the Rev range the knocking would get louder and the engine sounded like it was struggling (it was louder than it should be).

After quite a while of this happening and the dealer insisting that I get a tune up ($650 even though I changed the coils and the plugs were changed 4000 miles ago at that time) the CEL light came on and it was the APV valve stuck open. I brought it to the dealer and they said I should get a new intake manifold. Luckily it was still under warranty so the job was free. They asked me what type of gas I was using and I said 87 some of the time and 93 some of the time with no noticeable difference in the symptoms, but from then on I've used 91 or 93. As I drove it out if the dealer the CEL came on again. I brought it back and they said I should run some fuel additive in and it would go away. The car ran pretty well after that for a while, but I still heard the fluttering sound and experienced a little lack of power. (It seems to me that the fluttering sound is pinging just not as severe as when it knocks since when it runs like it's supposed to, I don't hear the fluttering sound.)

Recently, I experienced louder knocking again after driving for a while and very rough idle, I changed the plugs and wires but that didn't help. I cleaned it again with the zoom power cleaner and again at 6000 RPM, it felt like I took my foot off the accelerator and the CEL went on for a few seconds. I couldn't read it since it went off a minute later. I brought it to the dealer again and they said they didn't feel any lack of power after a short test drive. (Duh! I told them it happens after driving for a while) They replaced the motor mounts which did fix the really bad rough idle but I still feel it ever so slightly. I asked them if they can do a compressions test and they didn't really want to. They said they can do it for $300 ( not happening).

Im really at a loss as to what the problem is. It seems to be worse after it gets fully warmed up and driven for a while, but I can't say that it's totally fine when its cold. Sometimes it runs perfectly even for a while, sometime it flutters quietly some times louder and sometimes it knocks loudly at higher RPM's. I just came back from a trip where it ran badly for 6-7 hours and then after sitting in traffic for a hour, at the end it was perfect. I've put in BG 44k a few times and it runs much better for that tank and a tank or two after that. It may still be a issue with the APV valve but why would it run fine with the BG44k in it. Also, I've driven times where it was fine in the beginning and I never went past 6000 RPM the whole way but it was much worse at the end of the trip. I redline almost every time I drive it and I try to put it through it's paces (I wouldn't have got this car if I didn't want to do that). It seems that the APV valve getting stuck from carbon was ( or is) more of a symptom of the problem (and exaggerates it) but its not quite the underlying issue. I've looked at the Cat and it's not glowing.

I've done a lot of searching here but I can't seem to figure it out, nor does the dealer seem to listen to what I tell them, so they're no good. My mechanic doesn't really know too much about the RX-8, and he said he'd be glad to help me but he needs some literature on how to get to the APV valve to clean it, if that's what I want him to do. (it seems from the research I've done here that you need to take the engine out)

This has been going on for close to 10 months. I really enjoy driving it when it works well, it handles like a dream, looks awesome and is really fun to drive but I can't corner when I don't know what the car is going to do when I push the accelerator. I'd just like it to work and do what it was supposed to do. I guess I could get a compression test from the local mechanic to rule that out? Maybe someone knows a dealer that listens to their customers and tries to fix cars instead of squeeze as much money as possible from their customers. (in the NYC area)? I just don't know where to go from here.

Thanks in advance.

Sleepy-z

Try another dealer, a compression test is covered ai believe if it fails under warranty but it may not fail. Sounds like the zoom zoom dislodged carbon and it sludged up, it cant really escape unless you remove the spark plugs and disconnectg the eccentric shaft sensor(crank angle sensor) next to the pulley and turn it over so the rotors turn and shoot out some of it, just realize your blowing oil out also, it probably wont help though. I would heat it up and run by another dealer and have them hope in for a test drive with you.

2tone

iTrader: (3)

wow...sorry...wasn't in the mood to read a novel

that sucks man. i didn't read the last part, but saw post #2...def go somewhere else (?) and get a compression test done. you will PROBABLY need a new engine, so i hope you're under warranty (if you mentioned that already, i skipped over it!!)

if you're out of warranty, they might be some caveat for the testing where they say you have pay for it, UNLESS the test comes back low. in other words, it's just to prevent every joe schmo w/ an 8 to walk up and say 'hey i want the cleaning and testing done b/c i felt a loss of power.' it's a known issue, so they just try to protect themselves from the onslaught of greedy customers. in essence, if your engine fails, which is sounds like it will, you don't get charged for the cleaning/testing (under warranty)...

gl, sorry for the novel myself!

Aseras

When you do the carbon cleaning ( seafoam or whatever ) make sure your car engine is HOT. Make sure it's all the way warmed up and then have it idle in your driveway and rev the engine for a minute or so till it is nice and toasty, even do it until the engine cut happens when it gets too hot. Then do the engine treatment. The hotter you get it the more carbon will get cleaned out and cooked off when you restart it. Also after the cleaning when most of the smoke is gone, make sure you redline the car a few times to really get it all out.

peterlemonjello

How many miles on your 8? Since you've covered just about everything that's most likely to cause the problem... my next guess would be the fuel pump. You may be experiencing fuel starvation at high rpms. If the problem gets worse the longer you drive the car this is symptomatic of the fuel pump failing too.

This is just a guess but it's similar to the problems I experienced when my fuel pump was going out.

nycgps

iTrader: (1)

Check your SSV, its not opening smoothly or at all.

Pin8

iTrader: (1)

It's got 67,000 miles on it.
nycgps, why do you think it's the SSV?

volcomx31

iTrader: (4)

pin8, did you ever resolve this problem? if so, how?

Pin8

iTrader: (1)

Well yes and no. I have found that when I use Gumout fuel injector cleaner fuel additive I have no issues so I just use that every fill up. I have no idea why it helps or what is the problem with the car, but it works fine with it so thats what I do. Maybe someone has some insight? Hopefully one day I'll actually fix the underlying problem.

volcomx31

iTrader: (4)

did you use the mazda zoom zoom cleaner to decarb?

Pin8

iTrader: (1)

Yes as well as seafoam, did this three times.

Old Rotor

Print this out and bring it with you. It says on the bottom that it's covered under the 8yr-100K warranty. You might be the next one......


http://www.finishlineperformance.com...4-08-1924g.pdf

epikeddie

It sounds to me that your engine is on its way out.

Fuel Pump starvation may be an issue especially at your mileage, but when mine cut out.....it was pretty brief and didn't have some of the symptoms that you're describing.

I would contact Mazda North America Operations if your dealership is being uncooperative. I've had to threaten my local dealership with the MNAO threat for them to do the coil inspection / de-carb TSB on my car.

Here's their information:

Mazda Customer Assistance Representatives are available

Monday - Friday, 6:00am - 4:45pm Pacific Time

1-800-222-5500

Pin8

iTrader: (1)

Thanks for the number, I'll give them a call see if I can get anywhere. As far as the TSB goes, isn't it just cleaning the engine with the zoom cleaner or do they do some other things as well? It seems like they check the SSV valve first so that may be helpful. I bought a compression tester and did a compression test. The numbers on that were fine, not to high not to low. The only thing that I haven't tried yet is the fuel pump (or lowering the engine out and checking the APV valve). The question though would be if it makes sense that it would get worse when its hot.

zoom44

personally i think the first situation with the wall at 6k was an undertemp situation. if the engien is not at operating temp OR THINKS its not at operating temp it will force teh revs to stay under 6500 .

i wonder if you are having radiator or fan issues.

the fluttering could be air moving through the heater core. lots of air could mean less coolant which could mean over temp situation.


seafoamed several times by you AND by the dealer equals dead cat which equals your problems since- no air out no air in

zoom44

what do you mean not too high? what were the numbers? explain how you did the test.

hot cat equals hotter fuel tank equals pump failure too. what year is the car?

zoom44

my typing is just awful

Pin8

iTrader: (1)

The temperature gauge never goes higher then about halfway so I assume that things aren't getting too hot. (unless of course the sensors are messed up but then how would I tell that)

I wasn't aware that cleaners mess up the CAT since they have nice labels and all proclaiming that they are totally safe for anything that you may ever imagine to use them for but thanks for letting me know! I won't use them freely anymore.

I haven't done a definitive test on the CAT except look at it and make sure that it wasn't glowing (not very scientific)

As far as the compression test I took off the drivers side wheel disconnected the fuel line pulled out a spark plug at a time connected the tester to the engine, cranked the engine a few times etc... I wanted to make sure that the numbers weren't too high since at least from the research I did, that would show carbon build up. They came out to be between 105 and 115 psi.

But again with all these things, why would using injector cleaner fix them? That just seems really strange to me?

volcomx31

iTrader: (4)

did the decarb with the cleaner help at all? do you get a knocking sound at idle?

Pin8

iTrader: (1)

I don't think the de-carb helped this my issues. I never heard knocking at idle but many times when I heard knocking at higher RPM's when it idled it idled at a lower speed then it should have and it stalled a few times.

volcomx31

iTrader: (4)

did your car sound like this? http://www.youtube.com/watch?v=Hk5A6MFla4Y. that is what mine sounds like..

ZumnRx8

^that loud? DAMN.. in a piston engine thats called ROD-KNOCK.... i dunno about rotaries.... mine idles kinda loud... but no knocking.....VOLCOM u still getting that diagnosis check by BHR at SS? or what not>?

volcomx31

iTrader: (4)

yeah..i am. hopefully someone can figure out what is wrong with my gay car! are you?

ZumnRx8

i probably will ... i need an engine diagnosis... i have hard shifting sometimes... very rare... and I wanna figure out if its my engine or TRANNY....

BTW.. we can compare noises from the engine at the CARAVAN.... maybe they are the same?? Do you get it when you are in drive also? Do you have power loss?

Im still under warranty at 70k mi

volcomx31

iTrader: (4)

i get the knocking all the time during idle in all gears..its just louder in D,M,R. i do get power loss sometimes, mainly when its hot