Car: 2004 RX-8 6MT, 35400 miles. Cold weather climate.

Symptom: Smooth idle, zero CEL light, zero stalling. Engine is ~40% down in power, dealer pulled misfire codes from the ECU.

There is a lot of hesitation when the engine is under load, the rev climbs slowly, especially in the 3-4k rpm range. Between 4000-7000 rpm it does seem to pull okay, but obviously not as smooth or strong as before.

Engine sounds rough, makes a groaning noise instead of the smooth turbine sound. Shifter is vibrating a lot more than normal.

Replaced all four spark plugs, didn't make a difference. The leading plugs had 25k miles on them. They do look a little grungy, but nothing out of ordinary for a rotary.

Dealer claim to have pulled cat to inspect the internal, and also did a compression test. Said both are okay.

I have 4 coil packs on order, will be replacing them next week. Dealer refused to do anything further until I get a CEL on the dash. Meanwhile my car is slower than a Rabbit diesel.

Other possibilities I've considered: bad plug wires, clogged MAF sensor (I don't have oil residual in my accordian), stuck VVT valve.

So what do you guys think? mysql101, MazdaManiac, anybody..?

 

its easy to check the coils id start there first, my guess is your going to find white marks on the underside.

 

Sounds like what mine is doing exactly, took it in and they said bad plugs and Coils, will be replacing them all Friday. I am at 50.7K miles. Safe to say yours is the same issue. Mine is an 04 as well.

 

here's how to check the coils:
http://www.finishlineperformance.com...16-07-1793.pdf

 

I thought i smeeled a BBQ

 

Remember... many a dealers say they have removed the CAt for visual inspection when in fact this is not the case.

It has happened to several members on the forum.

 

Be careful driving it before you replace the coils. If the coils are the problem driving them in that condition can take out the cat.

 

Umm, so I just unplug the harness from the coil pack and check the resistance across the terminals? Think I might try that tonight. I don't have a timing light, or I'd hook that up too.

I've thought of swapping the coil packs for L and T as a test, but I figure if it's T that's failing, swapping it to L will make things a whole lot worse. Might as well wait for the new coil packs to get here.

I've parked the car in the mean time, don't want to screw up the cat or foul up my brand new, $300 spark plugs. (is there a middle finger icon in the forum software?)

 

the coil packs are all the same, there is no L or T on them. (only the spark plugs are Leading / Trailing sensitive)

 

What you can do is you can try to swap the cables around.

remember to match it exactly as T to T, L to L

if should run a lot shittier if its failing.

 

I think this might help: https://www.rx8club.com/series-i-tech-garage-22/idle-quality-updated-engine-mount-brackets-107328/

Have your dealer/mechanic check your engine mounts. I have some of your symptoms (shaky start ups, shaky gear shifter) and I am going to replace the engine mounts. These symptoms are more obvious between 2-4k RPMS, 5-9k my car runs like before.

 

wat do you mean it will take out the cat? how so?

on full throttle, climbing up the rpms, mine stops limbing at 5000 rpms and sometimes will go beyond that...also it has a shaky rough idle.......replace the coils???

 

If you get no spark in the combustion chamber, the unburnt fuel gets dump into the cat where it goes up in flame and turn your cat into a tandoori oven.

 

yea because i took off my cat pipe section and i dumped out alot of the honeycomb ceramic stuff...and my 8 is laggy, has not get up and go anymore, and it bogs down after usually 5k rpms...sound like the coils need replacing???

 

Thats more like ur CAT is being cook.

I had that almost 2 yrs ago, and *eventually* all the filter material has been burnt then my car went back to normal. but of course I got a CEL, it smells bad, and Its bad for the earth.

Replaced it. not a problem since