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Sudden Rotor 2 misfire, Sounds like a motorcycle. No power.
Got my 2004 rx8 3-4 months ago, its my only car so its my daily. Absolutely love the car. It has a JDM motor (probably around 40-50k miles), AEM intake, HKS catback. I have been keeping up with oil changes, topping it off (I check the dipstick weekly), and of course a redline a day to keep the carbon away (Maybe a few more than one a day).
Mazda changed my plugs, and wires about 3-4k miles ago.
I was driving home yesterday and was doing my pull for the drive, at probably 8-9k rpm The car felt like it lost all of its power, and instantly sounded like a 2 stroke motorcycle. Flashing CEL, obd2 said rotor 2 misfire. It was only a small one block drive back home so I got it into my garage. I was weary of the obvious, a blown rotor, but to my surprise there was no smoke, it only smelled like unburnt gasoline. It surprisingly will start up, even if barely. The noticeable things about when its running now is that there is a rotor 2 misfire, and the car will shake pretty bad. CEL says rotor 2 misfire. I have tried resetting ESS already (20 brake pump). after ESS reset I tried to start it and got a backfire so loud it sounded like a gunshot. Ears were ringing for awhile. I'm honestly at a loss of what to do. I don't want to drive it like this, I feel like if its revved at all it will break. It feels like its running off one rotor.
I have a clip of what is sounded like before and after.
I really hope its not a blown rotor, I don't have the money to rebuild right now. (Covid is killing me man)
Any help is greatly appreciated, thank you, and thank god this wonderful community exists.
If you suspect possible engine damage, the only real way to know for sure is a compression test. Sounds like something catastrophic has happened though. At least try to rule out the engine itself.
If you can get your hands on a rotary compression tester that would be ideal. Its very easy to do the test. Just need a 10" extention with a swivel joint and 21mm deep socket to remove the spark plugs. Just take off driver side tire and access to the plugs are behind the flap.
The beginging of your old clip it sounds like a roaring V8, lol.
Check your ignition system, I have once the spark plug wire got disconnected from the coil.
Pull the spark plug and turn the engine, see if you get that puff sound.
Ultimately you want a compression test, but what I have listed are free items.
Also if you have a cat, remove that, misfire is NO.1 cat killer
In reply to Shaozhou Zhang
No cat luckily. Ill probably try to see if I get a puff sound First. Would I need to disconnect the fuel system to do this?
No. Pressing the accelerator pedal to the floor cuts all fuel to the engine for the purpose of dechoking. You would want to remove all the plug wires to prevent spark just to be safe.
Once again, thank you so much. Once I get a chance ill try these 2 things. I have to go pick up some deep sockets and a compression tester. I really appreciate both of you.
Good to know actually, guess thats one reason my mpg is awful haha. Would the plugs still work? Or would this be part of the problem?
They could be damaged but unfortunately, could be a major issue with your car. Clean them up gently and reuse until you can get a compression test done. Or, crank the engine with the plug out. You should be hearing consistent pulses when cranking over the engine. If you don’t, it’s likely poor compression. Ensure accelerator pedal is fully depressed before trying this.
I do hear the pulses when cranking I believe, I tired this before calling it a night. Its hard to say though the starter is very loud so its hard to tell for sure alone. But I do think I hear it. Im going to pick up a compression tester tomorrow and see what I can do. Thanks for the help.
The beginging of your old clip it sounds like a roaring V8, lol.
Check your ignition system, I have once the spark plug wire got disconnected from the coil.
Pull the spark plug and turn the engine, see if you get that puff sound.
Ultimately you want a compression test, but what I have listed are free items.
Also if you have a cat, remove that, misfire is NO.1 cat killer
I would suspect the coil as well if there is a misfire on Rotor 2. You can check with a timing light.
If you have a 04 and the coils are never changed, it's a very good idea to change them out.
BTW, I can see where the V8 comparison comes from, but it's obviously still a bit different. Does sound a little bit like a pushrod V8.
Tried a compression test at home, got actually zero on the rear rotor. I thought I did the test wrong so I tried it on the front rotor and it was 95psi.
Rear rotor has zero compression. What do I do now?
Sounds like you spun a bearing. If it was an apex seal you would still get a pulse or two then a 0. So the rear rotor isn't even rotating anymore. Engine rebuild seems most likely at this point. Either that or engine replacement.
Sounds like you spun a bearing. If it was an apex seal you would still get a pulse or two then a 0. So the rear rotor isn't even rotating anymore. Engine rebuild seems most likely at this point. Either that or engine replacement.
Yea, I was kinda in denial, I knew this was probably the case. I'm guessing driving it anymore would further destroy chances of rebuild?
Yea, I was kinda in denial, I knew this was probably the case. I'm guessing driving it anymore would further destroy chances of rebuild?
Its probably better to source a new engine. There's no telling what kind of damage is in there until its cracked open. Try to source a known good second hand Renesis engine and do a swap. Its the easiest and cheapest way. The proper way would be to buy a remanufactured unit from a profession rebuilder but thats more than double the cost.
That depends on the compression results of that 40K engine - it might be bad as well. Until they show you the test on that engine (picture of the rotary specific tester on the actual engine (VIN showing) I wouldn't buy it.
not unless you intend to thoroughly rebuild it first.
there’s really nothing about a jdm engine you want imo, unless you want a headache
What about the jdm engine is so bad?
Originally Posted by wannawankel
That depends on the compression results of that 40K engine - it might be bad as well. Until they show you the test on that engine (picture of the rotary specific tester on the actual engine (VIN showing) I wouldn't buy it.
Yea probably a good idea to get the compression first.
11-04-2020, 12:38 PM
Sudden Rotor 2 misfire, Sounds like a motorcycle. No power.
Yea, I was kinda in denial, I knew this was probably the case. I'm guessing driving it anymore would further destroy chances of rebuild?
