So I have an '05 RX-8 M/T and it has returned codes P2096, P0300, and P0301. I took it to the dealer, they ran some diagnostics, and it's supposedly misfiring quite a bit on the front rotor. They told me that the apex seals on the front rotor are wearing down, and the misfires are due to fuel squeezing in around, getting into the... er... chambers? (or is it more like a region? I love rotaries, but they sure are different) it's supposed to be in.

My mileage is also crap. I drive normally, making sure to rev every now and again, but I'm only getting around 14 mi/gal, and that's with premium fuel. When I rev the engine (and even every now and then with it idling) I hear popping out my exhaust, and the fumes of gasoline while the car is running are overpowering.

So I had come to the conclusion that I'd need to replace the engine, but I've been thinking, could this be a problem with the fuel injectors or something? It's definitely burning more fuel than it should.

Could I be on to something, or am I going to need to drop some serious dough on a new engine?

UPDATE:
Here's some stats on the car:
1) 2005 M/T, no navi
2) I just bought it in August.
3) ~126,000 miles
4) I'm the third owner, with the first two being brothers
5) Taken to dealer for all maintenance by previous owners

Here's the **** I've done to the car since I bought it.:
1) Replaced the coils
2) bought some plugs (haven't installed them yet, as the old ones are only have 10k miles on them)
3) installed an oil catch can
4) gave up and took it to a Mazda Mastertech where he did a code read, checked the cat for contamination (checked out fine)
5) He then took it to the dealer and got a Mode6 done on it
6) Told me it needs a new motor (suggested it might just be carbon buildup)
7) Used official Mazda engine carbon cleaner. Didn't work.

The Mode6 says that the front rotor misfired 62 times in the last 10 cycles, and 5 times in the last 1. It also stated that the rear rotor misfired 19 times in the last 10 cycles, with no misfires in the last cycle.

So as I said, it's out of warranty at 126k miles even though I can get a hold of the original owner quite easily, which sucks major nuts.

 

have you tried the giant search box about 2 inches north of your first post?

This is a super common issue and generally relates to bad compression...

 

^^what he said

 

Unless your car is over 8 years old or is over 100K miles, the engine replacement will be covered under warranty, provided you can show evidence of oil changes according to the Mazda requirement which is at least every 7.5K miles.

Get a compression test done at the dealer and go from there. Use the search function as it was pointed out - you'll find all the information you need.

 

Yeah, I did that. I dunno, I guess my ADD got in the way of finding a thread that would help.

I guess I need to get a compression test. I saw something mentioning a laptop setup, but searching is proving uneventful. How does one do this?

The engine is out of the warranty status, unfortunately. LUCKILY, I bought the car for $4000 when they were asking $6500, and I was told the engine would be about $2500 after core exchange (I think it was for parts only, I had told them I was going to do most, if not all, of the work).

So since most of the knowledge I've obtained on the mechanicals of cars has come to me within the last few years and I'm still a bit iffy on engines, does a bad compression test pretty much slap an engine with "dead" status? I know it can be from a bad head gasket on a normal engine, but with no head gaskets on a rotary, I'm unsure.

The way it is, it'll last me through the winter, but it'd be nice if there was a cheap fix.

 

Wow.

No where in any of your posts have you mentioned how many miles are on your car, what all tests you have actually done to the ignition system, and if you have done any simple maintenance on the car, like spark plugs, wires, and ignition coils.

You're just making the assumption that you've got a blown motor, but you haven't even looked at the engine yet. Maybe you have 1 fouled spark plug in the front rotor? Have you looked? Have you had them changed since you bought the car?

You probably should go back to the very beginning of troubleshooting your cars symptoms, go through the entire check list of potential causes, and eliminate them one by one. Once you've gotten to the point that you actually do have a blow motor, then you can start worrying about that.

BC.

 

I always like to rule out the compression first becuase it only costs $100 where the coil packs/plugs and wires cost $450ish

 

I need to stop doing this crap when I need sleep, it looks like. Anyways, I went ahead and updated the OP with that said information. I'm going to take a peek at those spark plugs pretty soon here (definitely before I rip out my Renesis).

Supposedly both the ignition coils and spark plugs had been replaced about 10k miles before I bought the car. I got coils and plugs on the cheap from Advance Autoparts and the coils were pretty easy to replace. I have the old ones still just in case they were perfectly fine.

And what's a good way to go about doing a compression test? I know I can do it during the process of replacing the plugs, but with three apex seals per rotor, doesn't that make things a little difficult?

Thanks for all the help, guys.

 

So, interesting development, I still haven't done a compression test, but it was time to replace the oil (second time I've done it since owning the car), and rather than take it to my usual service station, I used my father-in-law's lift to do it myself this time, and when I took out the drain plug, I swear at least 5 quarts came out of there. I was wondering why every time I checked the dip stick it was never below full. In fact, nearly the entire stick was coated with oil every time I checked.

So I filled it with the recommended amount this time, and--now I'm not sure if it has anything to do with my problem--it's running fine, more or less. I drove 80+ miles since the oil change, and the issues cleared up after about five minutes of driving.

Interestingly enough, I was having issues with the BRAKE(!) and TPMS warning lights coming on randomly (the TPMS would come on when the car started, brake light randomly while driving), and they seem to be gone, too. Does this make sense to anyone?

Thank you for any insight!

 

TPMS may come on when the tires are cold and the pressure is low. Driving warms the tires, the air inside warms & expands and the TPMS light goes out.
The Brake Light is controlled by the amount of brake fluid in the reservoir. As the pads wear, the brake caliper pistons move out and the fluid level goes down. Check the amount of pad left on all 4 corners if the fluid level is down before you just add fluid.

I was recently getting misfires and I determined it was contaminated gas (water or too much alcohol).

 

I'll make sure to check those things in the morning. The tire pressure one makes sense and I had considered it. I just found it odd that both that and the brake light deal happened around the same time and now they're gone. I mean gone gone. Normally, even in only a 5-minute drive, the brake light comes on. I drove it a whole lot today (warm day, cold night) and it drove like a brand new car, minus the CEL.

Thanks!

 

but you cant get a good compression reading without having at least decent ignition. if its . if its been flooded or nearly flooded the compression will be poor because the oil film will have been washed out. if its misfiring because of dirty fouled/old plugs then you wont get a good compression reading because of the same oil film washing effect.

 

I wouldn't agree with that Zoom. The oil film isn't creating compression itself. The only way a faulty ignition could impact compression is if the plug is cracked or damaged and allows a leak.

 

you cant get a good compression test with a flooded or "partially" flooded engine. the poor ignition contributes to that situation.

 

Well, whatever the case, the CEL turned off on its own this morning and the car has been running like a charm. The brake fluid was low, but all the pads look to be just fine, so I may have a small leak that I didn't know about. I added some fluid and the light's back off.

I'll get that compression test soon, just in case, but right now it's like new. Thanks for the input, guys, it really helps.

 

Alright, here's what's up. I was nearly empty on gas, refilled to full with 91 octane as usual, and the performance issues came back. CEL is on and all. I'm wondering WTF? and then I remembered: when I changed the oil, I also put some Gumout fuel system cleaner in with a fresh tank of gas. With that in, the car runs perfectly.

Why would it be doing that? I don't mind putting some in with every fill, but it says to only do so every 3000 miles. I assume that that number is more or less BS, but still.

Any thoughts?

 

They flooded your engine with oil? I assume it was the "service station" you mentioned. Hmm. Might want to check the MAF tube and clean the MAF. I would say a lot of oil has been vacuumed up into your intake.

 

Thing is, I've cleaned the MAF and have an oil catch-can (did them both at the same time). There was some oil in the can when I last checked, but very little. Do you think I need to replace the MAF? What about the fuel injectors? I find it odd that when I have a cleaner for them in the fuel the car runs like a dream.

 

Sounds like you might have some sort of contaminant in your tank/gas. Maybe water. I'd be looking into that first.

 

Okay, so, I let this tank run through and filled again with the Gumout fuel system cleaner, and voila, it ran smoothly again.

What's a good way to get rid of that water? Would it be wise to clean/replace the fuel pump? I'd be nice if there was an external filter on these things.

 

Well, the easiest way is to just drive the car until the tank is really low, add 4 gallons to mix it up, drive until low again, and repeat another time or two just to be sure.

For a quicker, more hands on approach, drive the car until really low on gas, then pop out the back seat, remove the fuel pump, then siphon out everything that's in there (use that in your lawn mower, or dump it into someone's tank you don't like) and then refill your car with fresh gas.

BC.

 

Note to self..........Never park next to BC or watch him carefully.

 

Hah, yeah, I could do that :D.

I ran it down to fumes today and filled her up with 91/cleaner. Purring again like a kitten. I found a place with 101 octane (I always laugh when I see an octane rating over 100, as when that system was implemented, the number is a percent). Has anyone tried putting 118 in it? Some guys at Advance Autoparts recommended putting in 3 or 4 gallons after it had completely emptied and run that through.

 

Poor a bottle of Heet in it after your next fill up. Its made to help prevent water in the gas tank. My quick suggestion...... if that is your problem.

 

Change gas stations, go to one in an area that has higher end cars. These are more likely to use premium gas and the station's tanks will be refueled more often. This has been my recent experience. The cut-rate stations will sell mostly regular grade fuel, because the customers are looking for a bargain.