AlphaBlue

I have a 2004 RX8 that I bought used about 8 months ago. Its current mileage is a bit over 47,000
Shortly after I had to have the engine replaced with what the service team explained to me was a new updated factory engine. After which the car operated great for about 2 months until I noticed low engine performance.

When starting, the engine sputters lightly but noticeable, then return to its normal idle.
The engine is sluggish when accelerating on take off with very little power, then after 2 to 3 seconds winds out to its normal rpm's

I returned the car to the service department and was told by the tech that he could not find anything wrong and to bring it back if the engine check light comes on.

If any one has experienced the same problems or can offer any advice I would greatly appreciate it.

05rex8

iTrader: (7)

I suggest finding a new dealership.

I would check the cat, coils, plugs. GL.

ILoveFI

Two words: Ignition Coils

I took my car into the dealership for "Lack of power" as the car would sort of sputter when turning on as if it had a REALLY weak battery and then when accelerating after 1.5-3k rpm it would return to a normal RPM but would pull REALLY REALLY slowly.

They diagnosed the problem as some spark plugs as the car had about 170 counts of misfiring. They replaced the plugs said they fixed the problem, didn't happen.

Took it back in they put the computer on it said nothing was wrong so I talked the mechanic into LOOKING at the ignition coils, which I said was probably the problem in the first place. He looked at them, replaced them, VOILA! Fixed problem.

XRX8X

i wish my problem was as simple.took car in for the lost of power recall and the damm thing got worse and worse on performance.took it back and did the coils and plugs(myself)and still have a kinda knocking in the 2nd rotor.been there for two weeks(at the dealer) now and they said maybe the cat(not so been replaced).or some kinda broken off piece from the cat.i have never heard of a cat.converter backing up into the engine i was pretty sure the exhaust is just that exhaust.only the intake would suck.but this is what mazda tech line told these guys to check for.don't know whats next but i want my baby back.(not ribs!!)2004 6sd G.T.w/55,000.i time flooded, all updates and oil changed on time or before dueand no low oil running.totally baffelled

XRX8X

now remember that after every recall the car started running worse than it did before the reflashes and oil metering flash.oil use went up to a quart per 1,ooo miles instead of the qt.use every 3,000 miles ???

whitebeau

clogged cat.

If your in the USA. theirs a federal Emmissions Law that warranties the Catalytic Converter for up to 80k miles. I just had mine replaced, it was doing the exact same thing during warm up.. and no power above 6k-rpm and became progressively worse.

I also had an engine replacement this last January, along with an OMP replacement 2 months ago.

My Perceived Root Cause:

Mazda Engine deflood process "Add oil to intake manifold" done on my car with the old engine. which also had the engine recently replaced this year, will eventually clog the cat. I had my 'deflood' process done on the old motor 3 times before the engine was diagnosed with a failed side seal, warrantying the engine.

i know my car smelled like oil in the cabin when i first bought it and thought of it as 'normal' for a rotary. But the dealer also warned on initial purchase of how much smoke it will 'blow out' if the engine floods... So the old motor had roughly 6quarts of oil poured into it with an 'guestimated' 5-6 Mazda spec'd deflood process.

have them check the cat. Dealer was asking $1,400.00 for the part before i called Mazda USA to have them authorize an approval.

(Note: Call to Mazda USA was needed, as the Emissions law in CA is 70k for emissions with the exception of the Catalytic converter. Which the dealer perceived otherwise. My car was initially sold in CA. Relation with the dealer is great, and they were fine with me making the call as all their resources for Warranty coverage have been exhausted).

whitebeau

same here.. with the latest flash. I've noticed an increase in Oil consumption.. about 1/2 a quart every gas up.... i usually drive WOT until 'recommended' speed limit is reached....

whitebeau

Sorry. I just reread your post. Mine had a rough idle on warmup.. no sputtering, they ever give you what the CEL code was? or did the car throw any CEL?

The techs after they swapped my engine were scratching their asses as it also had a startup stumble problem until they flashed the PCM noticing it was way out of revision...

+1 on the coils in place of clogged cat. Sorry i didn't read the post thoroughly

Damara

Hey, I have a 2004. It has about 106xxx miles on it, Depending on how long the car has been running, it has a very rough idle, loss of power when speeding up, BAD! If it goes above 4k rpm, its makes a strong rattling sound. It comes and goes, more so when im going up hill. Advise and words of wisdom PLEASE!!