I apologize if this has been covered in other threads. I did my part searching and did not find a similar topic.

My RX8 has misfire problems. In January it showed the symptom for the first time and I had it toed to the dealer, as they recommended. They said they could not find a problem but to 'bring it back if it happens again.' The dealer refused to run any tests on the health of the engine.

The problem did reoccur a couple weeks later, and I replaced the coils myself. That seemed to cure it.

Yesterday it came back. I ran through a large puddle (wide, not deep; no water reached the intake) and the car immediately started misfiring. I had it towed home, then to the dealer.

This time they say it's running fine again, but that it does this because I'm using synthetic oil. They also claimed that I may have done serious damage to the engine by doing so. I asked, if that was the case, if they'd do a compression test (since the service writer used the words 'low compression') to check the health of the engine. They refused to do so.

They also claimed that the car was not storing any fault codes. I read a single code off the car yesterday, for a 'cylinder #2 misfire,' and did not erase it.

I'm pretty frustrated at this point. Whether or not you're a proponent of synthetic in rotaries, I fail to see how the oil is the cause of my misfiring problem.

Thanks.

screw them, take it to another dealership....misfires arent cause by the type of oil you use, its either your plugs or coils going bad...

What they are suggesting is physically impossible unless you are injecting oil as your primary fuel.

Don't worry misfires are common.

you won't get rid of them. Car is pig rich from factory.

Re-set ECU

If it continues to misfire after two re-sets then you need to investigate the problem or driving habits.

I second Dozer's recommendation to try another dealer.

On the puddle thing...check the plug wires to make sure they're on firmly, have dielectric grease to keep water out, and are now dry.

Ken

With water being involved right as you through your misfire...Im with ken-x8. I might even go as far as replacing the wires depending on mileage.

With water being involved right as you through your misfire...Im with ken-x8. I might even go as far as replacing the wires depending on mileage.

Agreed. Wires should be done at the same time as coils/plugs. It's cheap insurance.

I also second finding a new dealer.

I'm curious to know how they are sure the OP is using synthetic oil. I'd be surprised by a dealership that would refuse to do a compression test, but would do a forensic analysis on oil to determine if it was dyno or synthetic. That's the sort of info I wouldn't volunteer to them.

Sorry I didn't get around to writing an update last night. After I picked up the car we were really busy.

I have the car and it's running fine. Basically the dealer doesn't know why the car does this. The service manager called me and agreed that the synthetic oil theory is ridiculous, and finally admitted that they have no idea what's happening. They're going to try to escalate the issue through Mazda, but he wasn't convinced they'd find a solution without the failure being permanent.

When I asked the service adviser why he refused to do a compression test, he said that he misunderstood me and thought I was asking if he'd recommend one. I think it's basically the same thing, and that if he thought I had done 'serious damage' to the engine a compression test is the way to test that theory. If he doesn't think his theory will stand up to that scrutiny, why present it?

Really, the car's running great. I took it for a short drive after leaving the dealer and it's totally back to normal.

I have another set of plug wires. I'll install them once it's dry and warm outside. Right now it sucks outside.

I second Dozer's recommendation to try another dealer.

On the puddle thing...check the plug wires to make sure they're on firmly, have dielectric grease to keep water out, and are now dry.

Ken

While I wouldn't eliminate the wires as a suspect just yet, when the misfire happened I was able to disconnect all the wires and reattach them. None were wet. One wasn't on real snug, and I crimped the connector a little to tighten it up.

As I said, I have a new set of wires. I'll install them this week, but I expect no change in the car's current behavior.

I would never EVER tell a dealership you are running synthetic oil. What they don't know won't hurt you. They can not test it anyways and have no idea what you are using. Why some are scared of an analysis I have no idea as you can send it into Blackstone labs for an oil analysis and even they can't tell you if it's synthetic or conventional. They can only tell you what's in it not how it's made. Don't be afraid of using synthetic. Just don't tell anyone. No one can really complain it's dishonest as it isn't going to cause anything to fail anyways. It's more dishonest to deny a claim based on the fact that it's there. Therefore ignorance is bliss.

And I was ignorant about telling the dealership. :) After I dropped the car off they called and asked if I was using synthetic. In the interest of an honest exchange between us in order to determine the cause of the problem, I told them the truth. I had no reason to suspect they'd settle on any random, inconsequential factor as the cause.

They no longer suspect it's the cause of the misfire. Their manager has set them straight on that. They just don't know what the actual cause is.

Start your car with the hood up...let it idle for a bit and be normal. Then take a spray bottle and spray water on your wires and see what happens. Do it at night and you might even see them spark if they are bad.

:bsmeter::bsflag::wtf:

uggh. misfire happens. it just does. one time it will be because of a coil issue , next it will be a plug issue and another time if will be a wire issue and sometimes it will just do it for the hell of it.

i have no idea why you had it towed. misfire is never a reason to have the car towed.

as for why they didn't see the code. misfire codes are only stored for a certain amount of time. if no other misfire is sensed then it erases the code. if it detects enough in that time frame then it will light a solid cel. your car didn't detect any more so it erased the code and they didn't see it.

uggh. misfire happens. it just does. one time it will be because of a coil issue , next it will be a plug issue and another time if will be a wire issue and sometimes it will just do it for the hell of it.

i have no idea why you had it towed. misfire is never a reason to have the car towed.

as for why they didn't see the code. misfire codes are only stored for a certain amount of time. if no other misfire is sensed then it erases the code. if it detects enough in that time frame then it will light a solid cel. your car didn't detect any more so it erased the code and they didn't see it.

I had the car towed because the dealer has told me that I shouldn't drive the car when the misfire happens. I also assumed that they wanted to see the state in which car misfired so they could figure out why. Apparently they did not. All they did was clear the code, start the car and drive it, which is what they told me not to do.

When I said they didn't see the code, that was a result of poor communication on their part. The dealer later explained to me that they had read the code that was stored when the car arrived, but erased it and then no more codes cropped back up.

Yes, it was storing a code. I read it myself. I understand that an isolated fault won't store a code.

Anyway, you're not the first in this thread to say, 'misfire happens.' How serious of a misfire would you excuse as a quaint rotary quirk? Because this was consistent, no power, giant cloud of smoke misfire. Does that 'just happen?' Is that something I should just accept as part of life with a rotary?

Or are you referring to the misfire that results from dirty plugs or sketchy coils, where the engine doesn't quite rev smoothly?

plug and unplug your maf sensor. look at the wiring.

the big other idea, and i had this happen just recently.. and you mentioned a puddle..

reset your eshaft sensor. brake dance!

i kept getting an odd missfire on cruise. then it would throw a hard 300 code.

reset the eshaft sensor all is well.. :)

beers :beer:

Because this was consistent, no power, giant cloud of smoke misfire.

ok see you didn't say that earlier. did this big cloud of smoke happen in January , yesterday or both?

ok see you didn't say that earlier. did this big cloud of smoke happen in January , yesterday or both?

wow, did not see that either..


beers :beer:

I have seen some smoke before, but not like that. Of course, I was under full throttle when it happened this time because I was in the middle of an autocross run.

In January, after the dealer had already given the car back to me once without doing anything, it happened again a couple weeks later. The car misfired all the way home (which is only a mile) and a friend was following me. He said that big, burning chunks of catalytic converter were coming out of the exhaust. When I say it was misfiring, I mean probably only one rotor was working. The car had almost no power and was difficult to get moving. It had done this a few times before when I first started the car and went away as it warmed up. Replacing the coils fixed it at the time. Now it's back, and at random, not just when cold. The car had been running in the grid for probably fifteen minutes before that run, and it was probably in the low 60s outside.

A friend, who was at the event, now tells me that the smoke started to trickle out of the exhaust before I hit the puddle. So I'm not sure I really suspect water any more. There was a long, fast slalom right before the misfire happened, and when the smoke started, so it's possible that violent left-right-left-right caused the symptoms. My car is much stiffer and has much wider tires than stock, so it's probably capable of higher lateral Gs. Whatever part is the problem on my car may be upset by that.

ok see you didn't say that earlier. did this big cloud of smoke happen in January , yesterday or both?

My mistake. That's why I wanted to clarify. 'Misfire' meant something different to you and me.

If you are blowing chunks of the cat out of your exhaust then of course it's going to misfire. Your exhaust is clogged and air can't get out. A cat issue can be a frustrating thing to diagnose sometimes. You don't always get a CEL from it. It may not even always cause the car to run bad. Sometimes the problem can be worst if the engine is warm but not cold. A cat issue isn't always obvious and if the MAzda techs are only looking for CEL's which is pretty common anymore, they may not find it.

Yes, prolly the synthetic.

S

If you are blowing chunks of the cat out of your exhaust then of course it's going to misfire. Your exhaust is clogged and air can't get out. A cat issue can be a frustrating thing to diagnose sometimes. You don't always get a CEL from it. It may not even always cause the car to run bad. Sometimes the problem can be worst if the engine is warm but not cold. A cat issue isn't always obvious and if the MAzda techs are only looking for CEL's which is pretty common anymore, they may not find it.

So you think the cat issue predates the infrequent misfiring? Because the misfire seemed to cause the cat problem. Also, 99% of days my car seems to run fine. This is like a switch gets thrown and suddenly one rotor stops firing.

A cat can start to show issues long before it completely fails. They may be subtle things like a perceived misfire every once in a while. As it gets worse, the engine may just not want to run at all. Your cat could have had issues for months before it finally died. Now I'm not saying for sure that your cat is the cause of all of your issues, but it is a very possible one. Brillo had a similar issue a couple of years ago. He had random misfire and replacing the cat fixed it. It didn't even rattle when you shook it after it was off the car. You just never know with those things.

Now that's very interesting. I think I'll call the service manager and ask if they might replace my cat, just to try it.

Here's a new symptom. I've taken the car on quick trips up and down the freeway twice today, just so I can accelerate up through the rev range a couple times in second gear.

Each time I did this today, at least once at WOT I've had a moment of hesitation from the car, then a hissing noise, clanking as I hear bits go through the exhaust, and finally a thin grey cloud and chunks - chunks I can see bouncing down the onramp - are expelled from the exhaust.

It did this before for awhile after I replaced the coils last time I had a bad misfire like this. It's been fine for a few months. At the time I figured the bad ignition parts caused the misfire and therefore damaged the cat. I wonder if it wasn't just the cat all along.

big chunksa cat were also not mentioned previously:banghead:

the engine trouble smoke happened at an autocross(which you didnt mention previously either:banghead: )

so there have been chunks of material fly out of your exhaust on multiple occasions and the cat hasnt been physically inspected or replaced yet?

you did an autcross knowing you previously had chunks of catakyst flying out of your exhaust?:icon_no2:

what modifications have you done to your car?

have you ever cleared the nvram with the 20 brakestomp clear? please have this sensor and its harness checked

http://www.rx8club.com/showthread.php?p=2971610&highlight=sensor#post2971610

Look, I'm sorry, but this has been going on for quite some time. Excuse me for not mentioning every little thing the car has done over the past six months. It's been a long, frustrating period. I find my seat warmers insufficient in very cold weather and my instrument cluster rattles. Better?

I have not modified the engine at all. It is on the stock intake with a K&N panel filter, and I have a Greddy cat-back exhaust on the car.

I'm going to drop the car off at the dealer in the morning to have them look at the cat and, hopefully, order me a new one.

I have owned, and worked on, a lot of cars and I have never had a problem with a catalytic converter. This is all very odd to me, and it seems to be a chicken-and-egg situation. I don't know which came first, the misfire or the bad cat.

I replaced the plug wires tonight. I had a new set I just hadn't gotten around to installing. In order to get to the coils, I removed the box that's attached to the side of the flexible intake tubing. It had a couple ounces of oil in it. I pulled off a couple of the vacuum hoses, and they were coated on the inside with oil. I have no idea how it got there, but that seems like kind of a lot.

While replacing the wires, I checked the rear leading plug, because it was easy to get to. It had brown crust on about 50% of it. I have ordered a new set just in case. I replaced these plugs only a few thousand miles ago, but both misfiring incidents occurred since then.

oil in the intake. you can get a kit from mazda to rework the venting to alleviate that. it may be under warranty. or you could install a catch can. it can get there from over filling and also from just topping off the oil and some "spilling" into the vent on the filler neck.


http://www.finishlineperformance.com/pdf/rx8/bulletin/01-050-06-1664.pdf

btw oil in the intake can cause bad maf readings which can make car run even richer than normal causing fouled plugs and misfires and lead to premature cat failure due to over temp situ caused by unburned fuel reaching the cat and igniting in it.

cat failure can be more common on a rotary than a piston engine because of higher normal egt's. so what is a small amount of higher egt in a boinger caused by the above scenario is enough to push the cat over the edge with a wankel.

I dropped off the car this morning, and the dealer claims the cat is fine. They ran a 'catalyst efficiency test' on it, and that told them it was okay. I asked them to remove the cat and actually inspect it, which they said they'd charge me for. I agreed, and they still claim it's fine.

I have no idea what to do about that. I do not think the cat is fine. The chunks that came out of my exhaust came from somewhere. The cat also rattles now, where it didn't before. The dealer agrees with me that the cat is what's rattling, but they still won't replace it.

I suppose my only course of action is to keep provoking it and see if I can get it to show more symptoms.

There's your problem. Zoom44 told you.

Put a filter on the oil spout. cap off the intake. Clean all the hoses and intake tube, clean MAF, install new plug as as they are fouled.

Seats, warmer is normal.

Dash rattling has been traced to small sand stones wedged between the steering column and dash. Can't get rid of the rattle if you have a KN intake. (You have filter so thats ok).

Also, KN filter has spray oil, get air compressor clean excess oil on filter. Many get oil from KN filter on MAF causing MAF and CAT problems.

Good Luck on the CAT, they are trying to save money. It passes test and works but is falling apart.

The cat inside is in two pieces - the first, the one you see when you look in, is about four inches long, then after the O2 sensor hole there is a second layer, about eight inches long. This second piece could be destroyed, and rattling around in the muffler, the cat efficiency test would still be fine.....

I had the same situation before(miss fire, and engine light on sometimes), it was solved after spark plugs replaced

congrats on your new catless midpipe.

:lol:

can u go another dealership ?

I dropped off the car this morning, and the dealer claims the cat is fine. They ran a 'catalyst efficiency test' on it, and that told them it was okay. I asked them to remove the cat and actually inspect it, which they said they'd charge me for. I agreed, and they still claim it's fine.

I have no idea what to do about that. I do not think the cat is fine. The chunks that came out of my exhaust came from somewhere. The cat also rattles now, where it didn't before. The dealer agrees with me that the cat is what's rattling, but they still won't replace it.

I suppose my only course of action is to keep provoking it and see if I can get it to show more symptoms.

call the mazda 800 # and explain the what happened. they will call the service manager and it should go better from that point.

if not escalate it with mazda na on the phone. ask for the area rep..

if the dealer said they did a visual inspection and you did not get a look, or no photos. with the stuff you have described, sucks to be them..

beers :beer:

call the mazda 800 # and explain the what happened. they will call the service manager and it should go better from that point.

if not escalate it with mazda na on the phone. ask for the area rep..

if the dealer said they did a visual inspection and you did not get a look, or no photos. with the stuff you have described, sucks to be them..

beers :beer:

To be fair, the service writer offered to show me the cat if I came to the shop to see it. Unfortunately, they had my car at the time.

Of course, it would make sense that I would have to be there to press the issue - I've had to hold their hands every step of the way so far.

Their service manager is supposed to call me when he gets back in to work Monday. If I can't convince him to replace the cat, then I'll escalate it up through Mazda NA. He seemed like a pretty reasonable guy, so we'll see.

I've run royal purple 10W30 for 5 years in my car and never had an issue. I also get ~17mpg in the city and ~24 hwy and I don't baby the car.

I suggest a different dealer who isn't an idiot.

Update:

The service manager has had my car, driving it as his own, since Monday. He has seen no problems with it in that time. This does not surprise me. It goes months in between misfiring and the exhaust had stopped spitting out chunks before I dropped it off. Of course.

They were able to find one Mazda service bulletin that recommends against using synthetic engine oil. The bulletin is for hard starting. I will post the bulletin number later; they're providing me with a copy.

Sigh.

When I pick it up after work, I will change the plugs. I just replaced them a couple thousand miles ago, but they're very crusty already. The car acts like it did before I replaced the plugs last time. It's just not quite as smooth.

I will also clean the oil out of the intake tract. I bought a can of MAF cleaner to use...on the MAF.

I have an oil catch can on its way. Maybe the misfire was caused by excess oil being ingested by the engine via the intake. I dunno. The can should get here tomorrow, so I'll have time to put it in and...zip-tie it to something, I guess.

We have another event Saturday. Here's hoping it doesn't act up again.

I believe I have found the source of my misfiring problems. After getting the car back from the dealer a couple days ago, I replaced the plugs. I had pulled one over the weekend, and it was pretty well fouled.

When pulling the plugs, I found that they weren't in the right places. Over the winter, because it was cold out, I had paid a local shop to put a new set in. I was very specific and told them that they had to go in the right places. Apparently they didn't listen, because one rotor had both trailing plugs and the other had both leading.

If you want something done, do it yourself.

It's running a heck of a lot smoother now through the rev range, which is pretty typical for having a new set of plugs in. We'll see, I guess.

I still have an oil catch can on the way. Hopefully that'll keep all the oil out of the intake tract.

I still think it's that evil synthoil.......

The sky is falling.

I believe I have found the source of my misfiring problems. After getting the car back from the dealer a couple days ago, I replaced the plugs. I had pulled one over the weekend, and it was pretty well fouled.

When pulling the plugs, I found that they weren't in the right places. Over the winter, because it was cold out, I had paid a local shop to put a new set in. I was very specific and told them that they had to go in the right places. Apparently they didn't listen, because one rotor had both trailing plugs and the other had both leading.

If you want something done, do it yourself.

It's running a heck of a lot smoother now through the rev range, which is pretty typical for having a new set of plugs in. We'll see, I guess.

I still have an oil catch can on the way. Hopefully that'll keep all the oil out of the intake tract.


Can you please contact the dealer and thank them for their help. You don't have to tell them what you found out. However, admiting that they were correct will go a long way in the future should you need their service.

I examined the ingredients on the MAF cleaner verses brake cleaner. Same except MAF ensures that is is safe for plastic while brake cleaner says safe on most plastic, do a test. Therefore difference in quantity of chemicals.

Can you please contact the dealer and thank them for their help. You don't have to tell them what you found out. However, admiting that they were correct will go a long way in the future should you need their service.

I examined the ingredients on the MAF cleaner verses brake cleaner. Same except MAF ensures that is is safe for plastic while brake cleaner says safe on most plastic, do a test. Therefore difference in quantity of chemicals.

I appreciate the sentiment. I left things just fine with the dealer. I know the service manager from his days at another dealer, and we get along just fine. I would like to tell them what I found, but I worry it would give them an out if the engine needs to be replaced under warranty in the future.

As for them being 'right,' I don't see how they were. They refused to believe me about the cat spitting out pieces. I still think that's a problem and it'll have to be replaced some day. They also never even looked at the plugs, obviously. I brought it to them to figure out (four times), I told them I had the plugs replaced over the winter, and they didn't think they should look at those.

They were also adamant that the problem was synthetic oil when an obvious problem was staring them in the face.

The service manager has admitted to being rotary ignorant. He literally knows less about the engine than I do, and I don't know a lot. They're nice guys, really, but without a website or a diagnostic machine telling them what to do, they seem to be lost.

As for the MAF cleaner, it smells exactly like brake cleaner. It eats oils and other contaminants much the same way, too. Neat stuff, and I'm sure entirely healthy to breathe. :p My MAF and entire intake were just dripping with oil. It was pooling. I have no idea where it came from, but I'm keeping my eye on it.

well the oil in ur intake is from it venting from the oil filler tube through the hose into ur intake....catch can will take care of all that!

Can you please contact the dealer and thank them for their help. You don't have to tell them what you found out. However, admiting that they were correct will go a long way in the future should you need their service.

I examined the ingredients on the MAF cleaner verses brake cleaner. Same except MAF ensures that is is safe for plastic while brake cleaner says safe on most plastic, do a test. Therefore difference in quantity of chemicals.

+1. seemed like the dealer actually cared. wow.

Hmm... maybe I should get a catch can as well.

Anyway, atleast you finally found your problems :)

Good Luck.

+1. seemed like the dealer actually cared. wow.

Sure, the service manager tried. He really did. But it's pretty clear to me at this point that they don't know the car very well and if the answer isn't on a screen in front of them they don't know what to do.

Again, I like the service manager at the dealer. He's a good guy. But they should have found this problem. I see no reason to tell them that 'they were right.' They missed a very obvious problem with my car and refused to believe me when I said the exhaust was coughing up chunks of cat.